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526 Cards in this Set
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- Back
Nutrition is ...
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the study of foods, nutrients, other chemical constituents, and the effects of foods on health & disease
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Nutrients are required for...
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growth, maintenance, reproduction
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Energy is measured in...
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Calories (nutritionists always mean kilocalories)
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Nutrients are characterized by 6 main categories, what are they?
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– Carbohydrates
– Lipids – Proteins – Minerals – Vitamins – Water All of these are "macro-nutrients" except for water, which is a "micro nutrient" |
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How are essential nutrients characterized?
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Life-sustaining
Must be provided by the diet The body cannot synthesize these nutrients in adequate quantities |
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Examples of some essential nutrients...
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Carbs, fats, proteins and water
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Examples of some essential vitamins...
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Vitamins A, B (6 & 12), C, D, E, K
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Examples of some essential minerals...
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calcium, iron, zinc...
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3 Types of Carbs...
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Simple- glucose (blood), sucrose (common), lactose (milk)
Complex - starches (long chains) Fiber - plant carbs (indigestible) |
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Sources of Protien...
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Animals and plants
Amino acids |
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Types of Lipids/Fats...
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Saturated fats- mostly animal (carbon molecules are saturated in their bonds with hydrogen)
Unsaturated - mostly plant Essential fatty acids - linolenic and linoleic acids Others: trans fat, cholesterol |
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How many kilocalories in carbs (CHO)?
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4 kcal/gram
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How many kilocalories in fat?
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9 kcal/gram
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How many kilocalories in protein?
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4 kcal/gram
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How many kilocalories in alcohol? (not a nututrient)
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7 kcal/gram
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Our requirements for nutrients vary as a function of...
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Age, Sex, Growth Status, Body Size, Genetic traits, Pregnancy, Breast Feeding, Illness, Drug use, Environment
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Excess energy from which nutrients will be stored as fat?
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Carbs
Protein Fat |
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How many vitamins in total?
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13
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Characteristics of vitamins...
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Organic micronutrients
Contain C, H, and O; other elements Do not provide energy Essential Vulnerable to destruction by heat, light, and chemicals |
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How many minerals in total?
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16 essential minerals
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Alcohol is turned directly into...
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Adipose tissue (fat)
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Vitamin D can be is a special essential nutrient because...
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It can be synthesized by the sun, but only on a case by case basis so it is still essential
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Characteristics of water...
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Inorganic
Contains only H and O Does not provide energy Participates in many metabolic reactions Provides a medium for transport of vital materials to cells and wastes away from cells Of all 6 nutrient classes, most foods contain water in highest amounts The nutrient consumed in greatest quantity |
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Phytochemicals are..
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plant chemicals
sudo-nutrient non essential and don't usually synthesize Rich in veg & fruits known to be protective against heart disease, cancers (sulfur) beneficial but some can be detrimental (alliin) |
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Examples of phytochemicals...
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Lycopen - beneficial in supplement form
Antioxidants - prevent/repair damage to cells by oxidizing pollutants (smoke, ozone, oxygen) |
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Malnutrition can occur from...
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inadequate or excessive intake
Increased need due to: Disease Genetic susceptibility Growth |
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How have animals adapted to nutrient availability?
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Fasting vs. excessive intake
Altered expenditure Storage of fuels Absorption Increases when stores are low Decreases when stores are high Excretion Increased filtration and loss through urine |
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Examples of malnutrition influencing disease development...
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Lack of calcium- osteoporosis
High sugar diet – tooth decay low fiber, high fat, low vegetable diet- CVD |
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Groups at risk for malnutrition...
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Pregnant & breastfeeding women
Infants Children Frail elderly Ill Poor/Inadequate health care |
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Key to a healthy diet...
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Variety, moderation, adequacy and balance
There are no good or bad foods only good or bad diets. |
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Major causes of death in Americans are...
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slow-developing lifestyle-related chronic diseases. Such as:
Obesity Coronary Heart Disease Cancer Diabetes Mellitus Osteoporosis Liver and Renal Disease Stroke Etc. ALL DIRECTLY RELATED TO NUTRITIONAL STATUS |
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% of U.S.A that is overweight or obese
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72.9%
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% of U.S.A that is obese
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33%
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Leading Lifestyle- Related Chronic Deaths...
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Tobacco use, currently the leading cause of preventable death in the U.S., killed 400,000+ people
Obesity – No. 7 leading cause of deaths in the United States in 2005 -- about 25,814 people. Obesity may surpass Tobacco Use as the #1 leading cause of death in the U.S. in future years - CDC |
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What is DRI?
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Dietary Reference Intakes (umbrella term)...
Decreasing level of goodness: 1. Recommended Dietary Allowance (RDA) (old term, still used, rarely able to achieve, only for 97-98% of people) 2. Estimated Average Requirement (EAR) (only able to determine for 1/2 of population b/c people over-consume) 3. Adequate Intake (IA) (new term, more of an estimate, used when RDA can't be determined) 4. Tolerable upper levels of intake (UL) (new term, almost never reached by food alone) |
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The RDA is...
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Not designed for individuals
A guide for food intake of groups Generous by design, except for energy |
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How is nutrition assessed for individuals?
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Historical information
Anthropometric data Physical examinations Laboratory tests |
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How is nutrition assessed for populations?
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National Nutrition Surveys
Food consumption surveys Nutrition status surveys National Health Goals |
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What is on the food label?
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Serving Size
based on an average amount people actually eat, may not be the amount you eat! Servings per Container Amount Per Serving; listed in cups and grams Ingredient List if more than one ingredient in descending order by weight |
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"Fat Free" is measured how?
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By weight not by calories
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Food Label: Nutrition Facts for a single serving.
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Calories (kcal) and Calories from fat
Macronutrients: Fat saturated fat polyunsaturated fat monounsaturated fat Carbohydrates (CHO) dietary fiber sugars Protein Cholesterol Sodium Vitamins and Minerals Vitamins: A and C Minerals: Calcium and Iron |
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Food Label: Percent Daily Value (% DV)
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shows how nutrients fit into the overall daily diet
based on a 2000 or 2500 calorie diet |
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What are daily reference values?
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based on 2000 and 2500 calorie diets
gives example of good diet structure adjustable depending on individuals kcal needs |
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What does it mean when foods are enriched?
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Replacement of vitamin and mineral loss to refined grains and bran
Ex. Thiamin, iron, riboflavin, niacin |
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What does it mean when foods are fortified?
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Addition of one or more vitamin/mineral to a food product
Ex. Folate, vitamin D, iron, etc. |
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Health claims must:
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be validated by scientific research
describe an association between a disease or health condition & a nutrient or food substance Examples: Calcium and Osteoporosis Folic Acid and Neural Tube Defects Sodium and Hypertension Dietary saturated fat and cholesterol and Cardiovascular Disease |
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Dietary Supplements...
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Do not have to undergo vigorous FDA approval
Cannot claim the products treat, cure, or prevent disease. Must have supplement facts |
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What is irradiation?
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Exposure of foods to gamma rays
Fragment DNA Destroys insects, bacteria, mold, microorganisms Enhances shelf life Reduces risk of food born illness Common practice Dried herbs, poultry, beef, lamb, grains, etc. Still controversial |
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What is a healthful diet?
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Adequate diets
Wide variety of foods – providing sufficient calories and essential nutrients Balanced diets Provide calories, nutrients, and other components in the right proportion |
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Example of fortification...
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Folate - all cereals are required to be fortified with this
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History of Nutritional Recommendations...
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1916 – Dept of Agriculture Nutritional Guidelines
1956 – 4 Basic Food Groups 1980 – Introduction of Dietary Guidelines Address issues of: dietary balance Adherence to the food guide pyramid Updated as new information is available Low saturated fat, trans fat, cholesterol. Moderate overall total fat - not to exceed 30% of total calories for a day 1992, the U. S. Department of Agriculture issued a Food Guide Pyramid 2005 - Dietary Guidelines for Americans (next issued in 2010) updated every 5 years by the Departments of Agriculture |
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2 Parts of Circulatory System
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Vascular System
Lymphatic System |
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What regulates digestion and absorption?
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Hormones and Nerve Pathways
System at Its Best |
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Overview of body functions...
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DIGESTION GI Tract
ABSORPTION Walls of GI tract primarily small intestine TRANSPORT Blood and Lymphatic System METABOLISM Cells within target tissues EXCRETION Large intestine (via anus), kidney, skin, hair and nails |
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1st step in body food processing:
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Ingestion
Regulated by internal & external cues: Hunger Appetite Satiety |
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Hunger is...
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physiological drive (internal cues)
metabolically motivated hunger signals can be overridden |
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Appetite is...
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a learned response (non-physiological; external cues)
Includes: site or aroma of food social or environmental cues time association |
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Satiety is...
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the cessation of food intake; meal termination
doesn't require being full Both physiological (internal cues) and a learned response (external cues) |
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Satiation is...
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feeling leading up to satiety, signals causing sequences of satiety
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Digestion is...
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Process by which foods are broken down into simple absorbable units
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Digestive system:
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mechanical and chemical breakdown of food.
all the organs and glands associated with the ingestion and digestion of food. |
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Alimentary Canal:
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from mouth to anus.
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What is digestion and absorption?
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Processes that make nutrients available for body to use
Nutrients transported via lymphatic and circulatory system (out of GI into cells) Eventually all nutrients go into circulatory system Large intestine: water, Na |
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What happens during mastication?
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chewing
mechanical breakdown of food salivary amylase is excreted - breaks down simple starches and carbs |
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What nutrients can be directly absorbed through the mouth?
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glucose and water
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The esophagus is...
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A muscular tube about 10" long
connector between mouth and stomach |
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Peristalsis is
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chain of rhythmic contractions that propels food to stomach
food transported through the diaphragm |
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Lower esophageal sphincter is also known as...
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cardiac sphincter (lies below the heart)
closes so food stays in stomach GERD - heartburn (gastro esophageal reflux disorder) |
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Stomach is...
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Muscular organ that grinds and churns swallowed food mixing with enzymes and acid
On the left side of the body |
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Chyme is...
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semi-liquid mass of partly digested food (vomit)
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Gastrin is triggered by...
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chyme in the stomach
it stimulates release of hydrochloric acid (HCl) |
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When HCl is released in the stomach it results in...
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drop in pH to ~2.0 and release of:
– protease: protein digestion Pepsin – Protein Digesting Enzyme (central is protein digestion) – lipase: lipid digestion (no absorption in stomach of nutrients) – mucus: protective coating |
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How is chyme released to the small intestines?
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through the pyloric sphincter
this is what makes the gurgling sounds after eating |
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What connects the stomach to the small intestine?
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the pyloric sphincter (only flaps out, but if it goes inward, bile can come out of vomit)
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Stomach is made up of...
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crisscrossed muscle layers (creates churning and mixing motions)
has mucus layer that protects stomach tissue (ulcers form if there's not enough mucus) |
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What are the 3 sections of the small intestine (IN ORDER) and their length?
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1) Duodenum (10 in)
2) Jejunum (8ft) 3) Ileum (12ft) |
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Chyme stimulates what?
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release of pancreatic juice
pancreatic duct ==> intestine |
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Pancreas secretes what?
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enzymes to digest CHO, fats and proteins and bicarbonate (a base) to increase pH to 5.5-6.5 (make it more neutral)
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Liver secretes what?
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bile which solubilizes or emulsifies water-insoluble fats
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What is emulsification?
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mixture of two immiscible (unblendable) liquids.
example: soap is an emulsifier, fat and water combine through emulsification |
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What does the gallbladder do?
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It stores and concentrates bile between meals; contracts to release concentrated bile during meals
you can have it removed, just have to stay away from high fatty foods |
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What is bile made up of and what is its purpose?
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made up of cholesterol
purpose - to emulsify fats ( holds small particles of fat in suspension with water) |
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What is absorption?
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Process by which simple nutrient components move from lumen of the GI tract into the cells of the GI tract
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Where does the bulk of the absorption occur?
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Small intestine:
duodenum jejunum ileum |
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What are inside the intestinal folds and by how much do they increase the surface area?
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Villi -- 15 times more surface area
Microvilli -- 300 times more both found only in small intestine |
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What is intestinal lumon?
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The area within the intestine
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What happens to villi during absorption?
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As food goes through GI tract the top of the cells get broken off.
30% of protein goes to replenish cells in small intestine. |
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What does the ileocecal valve do?
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joins the small and large intestines. Most digestible nutrients are gone at this point.
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What happens in the large intestine?
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Intestinal bacteria degrade some fiber to simpler compounds
The colon reabsorbs water and salts. (water concentrates feces) Waste is excreted as feces through the rectum and anus. |
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Colon =
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secum
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What is bili reuben?
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the black tarry substance that changes feces black/brown
if you can't process it you get jaundice (babies usually get this) |
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What is dumping syndrome?
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diarrhea
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What does feces consist of?
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dietary fiber
microorganisms water Also includes losses from: kidney skin liver epithelial cells shed by body hair and nails lungs |
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What are the different mechanisms of absorption?
** KNOW |
Passive diffusion (not common)
Does not require energy Facilitated diffusion (not common) require assistance to move across the membrane – minimal to no energy requirement (like a turn dial) Active transport (most common) requires expenditure of energy, lots of ATP use |
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Factors influencing GI function:
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Physical immaturity
Infants spitting up Aging Constipation Illness Diarrhea Nutrition Fiber = Effect GI structure & function |
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Common digestive disorders:
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Constipation and Hemorrhoids
Ulcers and heartburn Irritable Bowel Syndrome (IBS) Diarrhea Flatulence Stomach Growling |
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How are nutrients entering the cells of villus transported to the rest of the body?
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by either the:
Lymphatic system - fats and fat soluble vitamins A, D, E, K -or- Vascular (circulatory) system -carbs and protein (everything else) fats do make their way into circulatory system |
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What happens to carbs and fats inside cells?
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They are “metabolized” inside cells to produce energy
(plus water, CO2 and heat) |
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Why is the net energy yielded less for carbs than for fats?
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It takes mor energy to break a circular bond (carb) than a straight bond (fat)
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What happens to protein in cells?
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It is “metabolized” in cells to produce energy (plus H2O, N, CO2 and heat)
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What is a calorie?
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the amount of energy needed to raise the temp of one kilogram of water (about 4 cups) from 15 degrees Celsius to 16 degrees Celsius (59 to 61 degrees F)
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How can you measure the energy in food?
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Calorimeter
Direct measurement of heat produced Bomb calorimeter - all processed foods must go through this Calculate 4,9,4 calories / gm : CHO, fat, protein based on how fast it burns and the heat it produces Calorie chart or nutrient database |
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Energy leaves through:
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Basal metabolism – at rest – post absorptive state – room temperature environment
“Dietary thermogenesis” (thermic effect of food) Exercise-induced thermogenesis |
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what is basal metabolism? how do you estimate it and what is it affected by?
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the energy needed to maintain life when a body is at complete digestive, physical and emotional rest
Men estimate: lbs body weight X 11 Women estimate: lbs body weight X 10 affected by Muscle > Fat Male > Female Previous nutr. status Temperature: body and environment |
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what is the basal metaolic rate (bmr)
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Measurement of basal metabolism
2/3 of total energy used by the body Varies among individuals |
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The energy required to eat goes to what processes?
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chewing food
digesting food absorbing nutrients transporting nutrients storing excess nutrients excreting waste |
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10% of energy expenditure happens from what?
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the thermic effect of food (diet-induced thermogensis)
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What is the energy expenditure required as a % of BMR while being inactive? active?
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Inactive, sedentary 30%
Active, physically active, 50% strenuous exercise 75% |
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How do you calculate your energy expenditure?
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Basal metabolism: weight x 10 or 11
Physical Activity (BM x .3, .5, or .75) Dietary Thermogenesis: .1 x (BM+PA) Total needed: BM + PA + DT |
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How is obesity often treated?
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as a “subacute” illness, in which time-limited treatment will lead to a complete cure
it is a chronic disease |
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What is body weight made up of?
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fat + lean tissue + water
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What is BMI?
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Weight (kg)/height (m2)
Advantages: Independent of frame size Independent of gender Better correlated with body fatness No tables needed Conversions: 2.205 lbs = 1kg 2.54 cm = 1 inch 100 cm = 1m |
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Definition of obesity in ranges:
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BMI Status / Obesity Class
<18.5 Underweight 18.5 – 24.9 Normal weight 25.0 – 29.9 Overweight 30.0 – 34.9 Obesity I 35.0 – 39.9 Obesity II > 40.0 Extreme (Morbid) Obesity III |
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U.S Obesity Trends:
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1990 - 10 states w/ prevalence of obesity less than 10%
no states w/ prevalence equal or greater than 15% 1998: no states w/ less than 10% prevalence, 7 states 20-24%, no state greater than or equal to 25% 2007: only Colorado less than 20%, 30 states equal to or greater than 25%, 3 states equal or greater than 30% |
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What are the costs related to obesity?
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+400,000 deaths per year attributable to obesity
$117 billion/year in economic costs – in 2000 $61 billion in direct medical costs – in 2000 |
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What is the body fat percentages in males and females?
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Male 10-25%
Female 18-32% Storage primarily under skin (subcutaneous) around hips, upper arms, thighs, and abdomen |
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What is central obesity?
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(android obesity)
Fat accumulation around the abdomen (apple) This “visceral” fat more metabolically active---oxidative stress (under abdominal tissue) Inflammation-damage to blood vessels and tissues Associated with increase in disease-type II diabetes, high BP, cancer, etc. More common in men |
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What is gynoid obesity?
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Lower body fat (gynoid obesity)
Fat accumulation around the hips (pear)—subcutaneous fat Not associated with increase in disease More common in women Less associated with chronic diseases |
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What are the major flaws of BMI?
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Major flaws:
Body composition is not considered % fat % lean tissue Fat distribution Subcutaneous Visceral |
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Other ways to measure body composition?
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Anthropometrics
Waist to hip ratio (WHR) Fatfold measures Waist to height ratio Hydrodensitometry (Underwater Weighing) GOLD STANDARD Bioelectrical Impedance Potassium Counters (Whole Body and Segmental) Dual X-ray Absorptometry (DXA) |
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What are the health risks associated with being underweight?
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Further compromises status during disease
Particular problem in wasting diseases such as cancer, and AIDS Changes in physiology Amenorhea - Women cease menstruating when body fat < 12% |
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What are the health risks associated with being overweight?
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Coronary heart disease
Especially with central obesity Diabetes Type 2 diabetes risk 3x Cancer Obesity is associated with various cancers Breast, Colon Hypertension (high blood pressure) |
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Approx what percentage of Type 2 Diabetes may be prevented by weight loss of as little as 5 or 10%
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90%
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Lost productivity due to obesity:
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$3.9 billion, with $39.2 million in lost workdays
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1995: Cost attributable to obesity?
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$99.2 billion
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3 Factors that cause people to become obese
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1. GENETICS
2. METABOLICAL AND PHYSIOLOGICAL 3. ENVIRONMENT |
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Stages in food consumption.
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Hunger
Seek food/start meal Continue meal Satiation End meal Satiety |
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The general goals of weight loss and management are:
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At a minimum, to prevent further weight gain,
To reduce body weight if prescribed, and To maintain a lower body weight over the long term. |
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6 Strategies for weight loss and maintenance
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Dietary therapy
Physical activity Behavior therapy “Combined” therapy Pharmacotherapy Weight loss surgery |
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Reasonable timeline for weightloss goal
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= 6 months of therapy
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1 lb of body fat = how many kcal?
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3500
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What happens in weight loss?
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Decrease in:
Water Fat Bone density gradual weight loss minimizes loss of muscle and bone |
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An example of genetics and environment contributing to obesity...
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Pima Indians - genetically predisposed to be obese if their environment permits
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What does PAL stand for?
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Physical activity level
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From what part of the body do obese people expend the most energy? normal sized people?
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obese - extremities
- because there is less insulation there - more likely to have sweaty palms normal- core |
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Why do obese people loose more weight quicker?
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The larger the mass the greater the amount of energy expended.
They also have more water retention (weight fluctuates 2-5 lbs throughout the day depending on water) |
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Volumetrics says...
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adding water increases volume and reduces the energy density of high fat foods
adding air affects volume, but not energy density example. raisins vs grapes grapes have a greater volume (the excess water increases volume) |
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Summary of dietary intervention...
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SMALLER PORTION SIZE
REPLACE HIGH KCAL DENSE FOODS WITH LOW KCAL DENSE FOODS INCREASE FRUITS AND VEGETABLES EAT BREAKFAST SMALLER FREQUENT MEALS |
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The only two weight loss supplements approved for long-term use...
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Sibutraminie (Meridia)
Orlistat (Alli) |
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What is ketosis?
|
Lack of carbs
ketons are produces when the body doesn't have enough carbs - acetone is produced in the body This would happen with people on the Atkins diet. |
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What is the problem with high protein diets?
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Protein is the most satiating nutrient, but we don't need more than 10-15% in our diet.
|
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What happens in gastric bypass surgery?
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Stomach is almost completely removed from the GI nutrient flow.
Still need stomach to secrete enzymes into duodenum and ileum 2% die due to surgery complications |
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Why is Sibutramine (Meridia) so effective?
|
It reduces the presence of the transmitters seratonin and norepinephrine (neurotransmitters that aid in weight control)
|
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What is the risk of Xenical (Alli)?
|
risk of vitamin deficiency (blocks fat soluble vitamins A, D, E, K
binds to lipase so you can't absorb the fat; causes oily stools |
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Other types of gastrointestinal surgeries:
|
Vertical Banded gastroplasty - irreversible, more of the GI tract left, band and staples are used to create a small stomach pouch.
Adjustable gastric band procedure - less effective 50%, reversible |
|
Why is liposuction not very effective?
|
No more than 8 lbs. of fat permitted to be vacuumed per procedure in U.S. (though people bend the rule constantly)
Fat is active tissue—vascularization, hormonal release Re-distribution of body fat stores post-op |
|
Symptoms & Risks of Anorexia Nervosa
|
Self-starvation; < 85% Healthy wt
Often 300-700 calories per day Distorted food beliefs-overwhelming fear of weight gain Body dysmorphia Amenorrhea early osteoporosis, lack of estrogen regulation Hypothermia Death 33% incident of relapse 1% of adolescent women, 0.1% men in Western World |
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To be classified as having bulimia nervosa...
|
need to have recurrent binge purge syndrome at least 2 times a week for 3 months
loss of control and feeling of guilt during and after the binge 1-3% of women, 0.5% men |
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Treatment for bulimia...
|
Break the cycle
Organize the eating pattern Psychological counseling and anti-depressants Like anorexia, high degree of relapse (33%) Interestingly, pregnancy improves condition in almost 70% of cases (Seratonin increases in pregnancy and play key role in combating depression) |
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What is binge eating?
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Excessive intake without purge
Compulsive behavior Secretive Disgust after binge 30-90% of obese exhibit BE |
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What is Pica?
|
consumption of non-food substances
|
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Types of Pica...
|
Geophagia – clay, dirt (most common)
Pagophagia- ice Amylophagia- laundry starch Plumbism- lead Coprophagy – Eating of Feces (required in some animals; absorb nutrients the 2nd or 3rd pass) |
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How many carbs in:
1 cup Milk? 1/2 cup veggies? 1 fruit? 1 tsp sugar? 1 slice bread? 1 small dessert? |
Milk: 12 g
1/2 cup veggies & tsp sugar: 5 g fruit, slice bread, dessert: 15 g |
|
Sources of carbs...
|
Starch from grain products & veggies
Sugars from fruits & refined sweets Milk sugars from dairy NOT from eggs, meats or oils 55-60% of calories should come from carbs |
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Chemical makeup of Carbohydrate
|
C6H12O6
|
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Simple Carbs...
|
require little digestion
Monosaccharide ”One Sugar” (no digestion required) Disaccharide “Two Sugars” |
|
3 Types of Monosaccharides:
(in order of prevalence) |
1. Glucose
2. Fructose 3. Galactose |
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Glucose is...
|
Also known as dextrose (energy currency of body)
- Essential energy source - One part of every disaccharide |
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Fructose is...
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Also known as levulose
- Fruit sugar - Sweetest of sugars |
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Galactose is...
|
Rare as lone monosaccharide
- Part of primary sugar in milk With glucose (as a disaccharide) |
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3 Types of Disaccharides
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Sucrose - table sugar (also honey) (glucose and fructose)
Lactose - milk sugar (glucose and galactose) Maltose - breakdown product of starch (glucose and glucose) |
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What is glycogen?
|
complex carb
Storage form of glucose in animals branched molecule (every ~8 glc) glucose polymer |
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What is the function of glycogen?
|
Maintain blood glucose between meals
Provide muscle with energy during anaerobic exercise |
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How is glucose stored in the body?
|
Liver glycogen can supply body with glucose for energy needs (limited)
- Stores only enough for a few hours Muscle glycogen supplies glucose only for muscle energy (limited) Excess stored in fat (unlimited) |
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What is starch?
|
storage form of glucose in plants
|
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How much of our caloric need do we have stored in our body?
|
Only 1/2 of our caloric need per day.
|
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Starches are...
|
Amyloplasts
Amylose (30%)- Linear glucose polymer Amylopectin (70%) - Branched glucose polymer-less extensive branching than glycogen |
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What is the function of starch?
|
Provide an energy source for the developing plant
|
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What are the word endings for sugars? enzymes?
|
-ose = sugar
-ase= enzyme |
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Salivary amylase digests...
|
starch (amylose)
|
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HCL acid deactivates what once it reaches the stomach?
|
salivary amylase (no starch breakdown)
|
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The more branched the chemical...
|
the more can be stored in smaller places
|
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Enzymes in the small intestine:
|
Pancreatic amylase (from pancreas)
- digests amylose and dextrins |
|
Disaccharidases from small intestine:
|
Sucrase (glucose and fructose)
- Lactase (glucose and galactose) - Maltase (glucose and glucose) |
|
Carb absorption mainly happens in...
|
small intestine
- Active transport mostly - Absorbed into portal vein => Directly to liver |
|
What organ converts galactose and fructose to glucose?
|
the liver
they travel there via the portal vein (general circulation) |
|
What are the end products of carb digestion and how do they enter the intestinal villi?
|
monosaccharides and through the capillaries
|
|
What is found in the large intestine?
|
Indigestible CHO (fiber) found here
- Some breakdown occurs due to bacteria (microflora) - Very little energy derived from fiber little starch enters the Large Intestine |
|
What happens when someone is lactose intolerant?
|
Undigested lactose is fermented by GI bacteria - results in the production of gas & acids
not enough lactase Symptoms: Bloating, pain, diarrhea Lactaid supplements/milk-- treatment |
|
Causes of lactose intolerance...
|
Ethnicity
Groups with incidence: Asian, Native North American, African American Damage to villi Illness, medications, malnutrition Deficiency from birth Age |
|
Remedies for lactose intolerance...
|
Replace missing lactase enzyme
Milk with lactase Lactase tablets taken with food Aged cheese < cottage cheese Fermented milk < regular milk - yeast has begun to break down lactose |
|
How are starch and fiber similar? different?
|
similar:
Both are polymers of glucose - Different bonds connecting the glucose molecules together (alpha vs. beta) different: We can digest starch (amylopectin) Enzymes that break the bonds between the glucose molecules - Energy source We can not digest fiber Our enzymes do not break the bonds between the glucose molecules - Not an energy source |
|
4 Types of Indegestible dietary fibers
|
Cellulose - vegetables, fruits and legumes
Pectins - vegetables and fruits Gums Lignin |
|
Types of water soluble fiber and their metabolic effects...
|
gums, pectins
- bind with fatty acids - prolong stomach emptying time so that sugar is released and absorbed more slowly Oat bran Barley Legumes Fruits Metabolic effects: Lowers blood cholesterol Delays stomach emptying |
|
Types of water insoluble fiber and their metabolic effects...
|
cellulose, lignin
Vegetables Wheat Grains Metabolic effects: Increase fecal bulk Decreases intestinal transit time |
|
Normal concentration of blood glucose?
|
Between 80-120 mg/dl
|
|
Excess glucose from meal stored as
|
- Glycogen in liver and muscles - limited
- Fat reserves - unlimited |
|
What are the two primary hormones are released from the pancreas to regulate blood glucose?
|
Insulin - transports glucose into cells
Glucagon - releases glucose from storage |
|
If you get too little glucose from meal...
|
Gluconeogenesis
Protein converted to glucose Fat converted to ketone bodies Energy for muscles Not for brain and nerve cells Results in ketosis |
|
Glucose homeostasis: maintaining blood glucose concentration is vital. What are the extremes?
|
Too low = weakness, coma and death
Too high = vasculature damage, peripheral nerve damage, wasting syndrome |
|
3 Types of Diabetes:
|
Type 1: Insulin-dependent diabetes mellitus (IDDM); lack of insulin; destruction of pancreas
Type 2: Non insulin-dependent diabetes mellitus (NIDDM); insufficient use of insulin; insulin resistant; Western diets and physical inactivity are conducive Gestational diabetes: 3-6% pregnant women; disappears after delivery |
|
What are the recommended Carb and Fiber daily intakes?
|
CHO: 55-60% of energy (kcal)
Fiber: 25 gm/day or 11.5gm/1000 kcal |
|
What happens if you have too much fiber?
|
Can displace kcal and nutrients
Intestinal discomfort Interfere with mineral and nutrient absorption |
|
Types of artificial sweeteners (zero calorie)...
|
Saccharin
Aspartame Sucralose Acesulfame potassium |
|
Alcohol Benefits (moderate drink,1-2 drinks)
|
Increases HDL-cholesterol (clears cholesterol)
Protects against heart disease |
|
Alcohol Adverse effects (excessive drink, > 5 drinks)
|
Hypertension, stroke, liver cirrhosis, cancers, nerve system disorders
Associated with: Death from homicide, drowning, traffic accidents, suicide |
|
Proteins are made of...
|
many Amino acids (AA) connected together
|
|
What is the basic structure of an Amino Acid?
|
Central carbon (C)
Hydrogen (H) Acid (COOH) Amino Group (NH2) Exception: side group or side chain “R” |
|
How many different AA's? How many essential & non essential?
|
20 in all:
9 essential from food 11 non essential |
|
AA’s are connected to each other through a...
|
peptide bond (condensation reaction)
|
|
The enzyme that will break apart a peptide bond is called...
|
a peptidase
|
|
What is the name of the chemical breakdown that occurs in the stomach?
|
Hydrolysis
|
|
What is denaturation?
|
When protein looses its 3-D structure due to the acidic environment (HCl) of the stomach
|
|
What is pepsin and how is it formed?
|
It is the stomach's peptidase (enzyme that breaks the peptide bonds of amino acids)
The HCl in the stomach converts inactive enzyme pepsinogen to active form pepsin. |
|
What is the order of the GI tract?
|
Mouth
Esophagus Stomach Small intestine: - Duodenum - Jejunum - Ileum Large intestine: - Cecum - Colon Rectum Anus |
|
What is present in the small intestine to aid in digestion?
|
Pancreatic and intestinal proteases (enzymes specific for certain peptide bonds)
|
|
What do you call 2 AA's linked together? 3? 2-20?
|
2 - Dipeptide
3 - Tripeptide 2-20 - Oligopeptide |
|
Given that insulin is a protein what would its fate be if it were taken orally?
|
The stomach would denature it. That is why diabetics need to inject insulin so that it can bypass the GI tract.
|
|
What do intestinal cells do?
|
They absorb single amino acids, di- and tri-peptides
|
|
How do AA's get absorbed?
|
AA's must pass through the cell membrane, through the cell and then through the cell membrane again where transporters are located.
Absorption occurs through transporters specific for certain AA’s |
|
What is phenylalanine?
|
it is an essential AA that is converted into tryptophan in the body which increases mellatonin (neurotransmitter than makes you sleepy)
|
|
What are conditionally essential AA's? An example?
|
AA’s that are normally made providing the precursors are available.
People that have PKU can't metabolize phenylalanine or they will die (caused by inbreeding; prominent in Pennsylvania & Utah) Therefore typtophan becomes conditionally essential. For burn victims all AA's become condit. essential |
|
Which body processes do protein regulate?
|
Water (fluid) balance--prevent edema
Acid-Base (pH) balance--buffers Immune system - antibodies |
|
What happens in protein synthesis?
|
Transcription: DNA ==> RNA
- Taking the information from DNA and transcribing it into RNA Translation: RNA ==>Protein - Taking the information from RNA and translating it into an amino acid |
|
What does DNA stand for? RNA?
|
DNA=deoxyribonucleic acid
RNA=ribonucleic acid |
|
What is an example of error in protein synthesis?
|
Sickle cell anemia
- One AA is wrong causing the structure of hemoglobin structure to change resulting in a dysfunctional protein |
|
In protein synthesis what is the role of DNA?
|
DNA code controls : Which AA needed and what order AA go on new chain
|
|
What are the requirements for protein synthesis?
|
Requires: Calories Essential AA from AA pool Non-essential AA from synthesis or diet
|
|
Proteins are the building materials in what?
|
Growth and maintenance
- Muscle tissue - Bone tissue - Blood - Skin - Intestinal cells Repair - Clotting factors Replacement - Red blood cells (have no nucleus so they can't reproduce by themselves) - production within bone marrow Life span of ~120 days - Protein turnover Continuous breakdown and synthesis |
|
What are hormones?
|
Compounds made in one cell or organ that elicit effects upon other organs
Examples: Insulin and glucagon -Insulin: Half-life of 6-10 minutes (ceases to function, constantly needs to synthesize protein to release insulin) |
|
What is osmosis?
|
Water will move from an area of low solute concentration into an area of higher solute concentration. Solutes can be proteins, salt, etc.
|
|
What is happening in the body when a person develops edema?
|
If the concentration of proteins in the blood decreases, perhaps due to malnutrition, the effective solute concentration in the interstitial space has increased. Water will leave the blood vessels and enter into the interstitial space resulting in edema (swelling).
|
|
What happens in the protein role of transporter and receptor?
|
- In blood proteins transport:
Glucose Water insoluble compounds Fat, steroids, hormones, vitamins - Hormone receptor Insulin, glucagon, estrogen |
|
What are the 3 type of nitrogen balance in amino acids?
|
Nitrogen balance
a. Balance: intake = output - Normal losses include: urine, feces, sweat, skin, hair b. Negative balance: intake < output - Nitrogen consumed is less than that lost - loss due to stress or injury c. Positive balance: intake > output - Nitrogen consumed is more than that lost |
|
How do you use amino acids to make glucose for energy?
|
1. Deamination
a. Removal of the amino group (N) 2. Carbon skeleton then used to make glucose (gluconeogenesis) b. used for energy c. excess used to make fat (lipogenesis) |
|
What happens during the catabolism (breakdown) of protein?
|
AA converted to fat when excess AA are ingested
N from AA is reused for AA synthesis; excess is excreted in urine May cause loss of Ca in urine Kidney disease problem |
|
What is a complete protein? example?
|
Contains all essential amino acids in amounts we require
support growth maintain adult’s protein Example: - Animal proteins - Egg protein is reference protein (egg whites have all 9 essential AA's; standard again which all proteins are evaluated) |
|
What are incomplete proteins? example?
|
Lack “limiting” amino acid
- One essential amino acid that is not present in sufficient amounts Examples: - Cereals => lysine - Legumes => methionine Must be supplied by another food “complementary protein” |
|
What are the protein requirements for the population?
|
.8 gm/kg body weight
Protein RDA ~46 gm for women ~58 gm for men 10-35% kcal from protein Actual US Intake >90 gm >130 gm ~15% kcal from protein |
|
What are the protein requirements for athletes?
|
Athlete needs 1.26 gm / Kg (~90 gm)
|
|
Food protein sources:
|
Meat
Fish Poultry Eggs Beef & pork rich in iron but high in fat Dairy products select low fat (butter not good protein source) Legumes Cereal grains Seeds Nuts Plant sources of protein are low in fat |
|
What is the only AA supplement that became credible in 2002?
|
Typtophan - for people with sleep disorders
|
|
What is the most widespread form of malnutrition? What are the causes?
|
Protein-Energy Malnutrition (PEM) andProtein-Calorie Malnutrition (PCM)
Primary: inadequate food intake Secondary: disease states that lead to 1) low food ingestion, 2) inadequate nutrient absorption or use, 3) increased nutrient requirements, and/or 4) nutrient losses |
|
What are the forms of PEM/PCM?
|
Decreased Protein Kwashiorkor
Decreased Energy Marasumus Decreased Protein & Energy Marasmic 1. Marasmus (severe-chronic PEM) - severe deprivation or malabsorption of protein and calories Chronic food deprivation Children 6-18 mo. Impairs brain development & learning Muscle wasting, including heart Severe weight loss 2. Kwashiorkor (acute PEM) - inadequate protein intake or infections Primary decreased food intake Secondary due to a concurrent disease A disease primarily occurring in young children when sufficient kcalories, but insufficient protein is consumed; child suffers from edema, poor growth, weakness, and an increased susceptibility to infections |
|
What is the difference btw starch and fiber?
|
their molecular structures:
fiber - beta bonds starch - alpha bonds |
|
What are the two critical dietary fibers?
|
cellulose and pectins (in fruit and veggies
|
|
How does the body control blood glucose levels?
|
1) Rush of glucose into body - Beta cells of pancreas secrete insulin - promotes glycogen storage in liver and muscles and glucose uptake in cells
2)When glucose levels drop - alpha cells of pancreas secrete glucagon - promotes for gluconeogenesis (stimulates liver cells to break down glycogen) |
|
When the body is deprived of glucose what happens?
|
All other organs will cease to use glucose to maintain the brain, liver, lungs, heart and kidney.
|
|
What does diabetes mellitus mean?
|
Sweet urine (eww)
|
|
What did type 1 diabetes used to be known as?
|
Childhood onset diabetes
|
|
Aspartame is...
|
an artificial sweetener.
the most widely studied supplement in the world. 99 countries have adopted it as safe. |
|
Artificial sweeteners are...
|
man made
zero calorie sucralose and aspartame are both derived from nutrients |
|
What are the FDA requirements for weight loss supplements?
|
no side effects for vast majority of population
min of 5% weight loss in 6 months |
|
What is the primary site of digestion and absorption for carbs? What form do they need to be in at this stage?
|
Monosaccharides - in order to be absorbed
glucose and lactose - need active transport sucrose - need facilitated transport SI = primary site |
|
What is the primary site of digestion and absorption for protein? What form do they need to be in at this stage?
|
Di, Tri or single AA
need active transport SI = primary site |
|
What is the primary site of digestion and absorption for alcohol?
|
Stomach and SI
|
|
What is the primary site of digestion and absorption for fat?
|
SI
|
|
Y or N: All all fats lipids?
|
Yes
|
|
Y or N: All all lipids fats?
|
No
|
|
What are the classes of lipids and their characteristics?
|
1) Fats (triglycerides)
-solid, triglycerides/saturated fat, caloric 2) Oils -liquid, unsaturated fats, caloric, also exists as triglycerides 3) Cholesterol -used to make Bile (fat digestion), sex hormes, and Vitamin D (w/o cholesterol you can't make them) - non caloric 4) Phospholipids -makes up cell membrane bilayer, the surrounding barrier of animals cells |
|
What is a triglyceride?
|
glycerol with 3 fatty acid chains (interchangeable btw saturated and unsaturated)
|
|
In what form does fat...form?
|
In droplets
|
|
The longer the fatty acid chain, what happens to the food?
|
It becomes more solid
|
|
How much of dietary fat is made up of triglycerides?
|
98% (also a vast majority of body fat stores are also triglycerides)
|
|
What is the length range for fatty acids? What is the most common length?
|
4 to 24 carbons long (always even numbers).
18 is most common |
|
What are some characteristics of unsaturated fatty acids?
|
Unsaturated fatty acids may have one or more “point of saturation”
May be “monounsaturated” (MUFA) or “polyunsaturated” (PUFA) |
|
Name 2 polyunsaturated fats and the location of their first point of unsaturation.
|
Omega-3 fatty acids
First point of unsaturation next to 3rd carbon in chain Linolenic Acid : 18 carbon chain omega-3 Omega-6 fatty acids First point of unsaturation next to 6th carbon in chain Linoleic Acid : 18 carbon chain omega-6 |
|
Name the parts of a fatty acid.
|
Carbon chain (C,H,O elements)
Omega end (CH3) Carboxyl “acid” end (COOH) Chemistry of opposite ends allows FA to group together |
|
What is the point of saturation?
|
where the double bonds are introduced.
|
|
how is a fatty acid different from sugar and protein?
|
in its formation. it is circular
|
|
What are the 2 chemical properties that lipids exhibit?
|
LIPIDS ARE BOTH :
HYDROPHOBIC - (water-resisting, fat attract) HYDROPHILIC - (water-attracting, fat resist) Allows fats to attract each other, and group together, forming spheres |
|
Which end of a fat molecule is very reactive?
|
carboxyl end
|
|
what is saturation?
|
molecule is saturated in its bond with hydrogen
|
|
How many bonds can each of the following make?:
Carbon Hydrogen Oxygen |
Carbon: 4 bonds
Hydrogen: 1 bond Oxygen: 2 bonds |
|
What do carbon carbon double bonds do?
|
= alter the orientation of the molecule
- which leads to different biological functions and health implications |
|
Difference between saturated and unsaturated
|
Saturated: no double Carbon to Carbon bonds in chain
C-C-C-C *all possible hydrogens are bonded, solid at room temp (almost always) Unsaturated: one or more double bonds between carbons C=C-C-C=C *double bonds can be broken to add hydrogens |
|
What do double bonds do?
|
They make molecules more fluid. Unsaturated fats have more double bonds.
|
|
What are food foods with saturated fatty acids?
|
Animal fats
Meat Dairy products Butter Tropical oils (heat degrades many things. the weather you find them in made them develop into more saturated FA to protect cells) Palm and coconut oil |
|
Characteristics of a Monounsaturated FA (MUFA)
|
One double bond (C=C)
liquid at room Temp |
|
Characteristics of a Polyunsaturated FA (PUFA)
|
Greater than 2 double bonds (C=C)
Highly unsaturated liquid at room temp All Omega-3 and Omega-6s are PUFAs |
|
Example of Nonessential FA (the body can make it)
|
Oleic Acid from stearic acid by Desaturation
|
|
What happens in desaturation?
|
Insert carbon double bond,
removes hydrogens |
|
Examples of essential FA
|
LINOLENIC Primary Omega-3 Family Member
also, EPA (eicosapentaenoic acid) (20:5) DHA (docosahexaenoic acid) (20:6) LINOLEIC ACID – Primary Omega-6 Family Member -also, arachidonic acid (20:4) |
|
How do you identify a fatty acid's family?
|
THE LOCATION OF THE DOUBLE BOND CLOSEST TO THE OMEGA (METHYL) END OF THE FA IDENTIFIES A FATTY ACID’S FAMILY
|
|
Examples of Omega 3,6 & 9 unsaturated fatty acids and the location of their double bonds
|
OLEIC ACID:OMEGA 9 (DOUBLE BOND AT C 9)
LINOLEIC:OMEGA 6 (DOUBLE BOND AT C 6 AND C9) ALPHA LINOLENIC: OMEGA 3 (double bond…) |
|
If there is a picture of a molecule and it says the following on the bottom, what does this mean?:
ALA, C18:3, omega-3 |
Alpha Linoleic Acid
From methyl end, where is first carbon double bond? C3 or C6? C3 How many total carbons? 18 How many carbon-carbon double bonds? 3 |
|
What are the sources of omega fatty acids?
|
OMEGA 6
LINOLEIC ACID: VEGETABLE OILS, POULTRY FAT ARACHIDONIC ACID: MEATS OR FROM LINOLEIC OMEGA-3 LINOLENIC ACID: cod and salmon, flax seeds, walnuts EPA AND DHA: HUMAN MILK, SHELFISH AND FISH |
|
What is the important ratio of Omega 6 to Omega 3 that we should intake?
|
4 to 1
|
|
What is the recommended % of Omega 6 to intake daily?
|
5-10%
|
|
What is the recommended % of Omega 3 to intake daily?
|
0.6-1.2%
|
|
Are there any foods with more omega 3 than omega 6?
|
no
|
|
Fatty acids combine to form what?
|
tryglerides
|
|
What does hydrogenation do?
|
Improves texture, taste & cooking properties
Adds H at double bond Becomes solid at room temp Decreases health benefits |
|
What are the advantages and disadvantages of hydrogenation?
|
AVANTAGES OF HYDROGENATION
1. PROTECTS AGAINST OXIDATION (SHELF LIFE) 2. ALTERS TEXTURE (HYDROGENATED OIL BECOMES SPREADABLE) DISADVANTAGES: 1. POLYUNS FATS BECOME MORE SATURATED 2. UNSATURATED MOLECULES AFTER HYDROGENATION CAN CHANGE SHAPE: - FROM CIS (H’s on same side, naturally occurs) - TO TRANS (H’s on alternate sides, synthetic) |
|
When does hydrogren contribute to disease?
|
when it is incomplete
|
|
what is CIS confirmation?
|
both H are moved from the same side
|
|
what are TRANS FATTY ACIDS?
|
Hydrogens surrounding double bond on opposite side of the carbon chain
- causes the bent carbon chain to straighten, solidifying the chain -acts like a saturated FA |
|
What are the Eicosanoids?
|
EICOSANOIDS are derived from omega acids.
- Prostaglandins – inflammatory responses, clot formation or clot prevention, hormone regulation, etc. - Thromboxanes – clot formation |
|
What are the physiological effects if eicosanoids are derived from omega 6 FA? omega 3?
|
OMEGA-6 LINOLEIC ACID (18:2)
CONSTRICTING BLOOD VESSELS PROMOTING BLOOD CLOTTING PROMOTING INFLAMATION OMEGA-3 ALPHA-LINOLENIC (18:3) DILATING BLOOD VESSELS DISCOURAGING BLOOD CLOTTING REDUCING INFLAMMATION |
|
About phospholipids:
|
- Contain Fatty acids
- Cell membranes formation - Lipid transport (lipoproteins/cholesterol) They have: hydrophilic heads and hydrophobic tails |
|
about cholesterol:
|
(only from animal source)-Cell component, 2/3 made in liver
Bile Acid precursor Contain no Fatty Acids Plant Sterol or phytosterols – can reduce cholesterol absorption |
|
what do Plant Sterol or phytosterols do?
|
can reduce cholesterol absorption
|
|
how is bile made? where is it stored?
|
synthesized from cholesterol in liver, stored in gall bladder
|
|
what does bile do?
|
Acts as an emulsifier : holds small particles of fat in suspension with water so enzymes can break down triglycerides
|
|
what does bile help with?
|
fat digestion
|
|
what is the role of sterols?
|
Sex hormone production
a. Estrogen b. Testosterone c. Adrenal hormones - Corticosteroids Vitamin D formation |
|
what does fiber do?
|
Sequestering Cholesterol from Bile and excreting it in the feces
|
|
A high fiber diet does what?
|
helps reduce the risk of CHD, by lowering blood cholesterol
|
|
What happens in the stomach?
|
Minimum digestion – mixing to expose fat molecule-attack by gastric lipase
|
|
What happens in the small intestine during digestion
|
Fat entering the small Intestine stimulates release of cholecystokinin (CCK) causing the gallbladder to release bile into the small intestine
|
|
What happens in fat digestion?
|
Fats and watery juices tend to stay separate
Bile released in watery portion attacks fat, surrounds droplets and pulls into water layer Enzymes (lipases) can now break down fat |
|
how much of the bile do our bodies reabsorb?
|
Approximately 95% of the bile acids delivered to the duodenum are absorbed back into blood within the ileum.
|
|
What accounts for the majority of cholesterol breakdown in the body?
|
Hepatic synthesis of bile acids
|
|
how much cholesterol converted to bile acids and eliminated in bile every day?
|
500mg
|
|
What are the small molecules that get absorbed during digestion?
|
Glycerol, Short- and Medium-chain Fatty Acids
- Diffuse directly into intestinal cells and absorbed into blood |
|
what are the larger molecules that get absorbed in the body?
|
- Monoglycerides, Long-chain fatty acids
|
|
what are micelle and how are they formed?
|
emulsified fat droplets surrounded by bile
- Bile assists in micelle formation which are transported into intestinal cells |
|
What molecules re-form to triglycerides in intestinal cells? What is then formed?
|
Glycerides and fatty acids
Chylomicrons are then formed from triglycerides, protein and cholesterol |
|
how is digested fat transported?
|
via the lymphatic system
|
|
what are lipoproteins
|
emulsified fats for transport in blood
|
|
what are lipoproteins and the different types?
|
Lipoproteins: emulsified fats for transport in blood
Chylomicron -- food fat from gut to body VLDL (very low density) -- carries fats to adipose LDL (low density) -- carries cholesterol to body HDL (high density) -- removes cholesterol from body |
|
the HIGHER the triglyceride level...
|
the LOWER the density.
|
|
fat, in the form of what, is much less dense than both cholesterol and water?
|
Fat as triglyceride
|
|
why can't a chylomicron go directly from the intestinal cell to blood?
|
b/c blood capillaries and intestinal wall is too small
|
|
about the chylomicron:
|
A water soluble transport vehicle for dietary fatty acids
Synthesized in the intestinal cell Transports fat to cells Leaves intestinal cell through lymphatic system, then travels to thoracic duct where it can enter bloodstream b/c it is big enough to allow it to enter |
|
where does the chylomicron remnant go for destruction?
|
the liver
|
|
what is the order of the chylomicron lipoprotein pathway?
|
intestine=> chylomicros=>triglycerides=>fat & muscles
once the chylomicros are devoid of triglycerides (phospholipid shell and cholesterol) it goes to the liver and gets destroyed. |
|
what are chylomicrons essential for?
|
absorption of large triglycerides and other associated fat soluble compounds
|
|
how are the chylomicros able to enter the lymphatic system
|
via the lacteals located near to and associated with the small intestinal cells
|
|
About VLDLs
|
Lipoprotein made by liver
Consists mostly of triglycerides - also of protein and cholesterol Transports lipids to various tissues in the body |
|
About LDLs
|
Derived from VLDL
Meaning, after an LDL downs off triglycerides to body it BECOMES an LDL Consists mostly of cholesterol Transports contents to all cells ‘bad’ cholesterol -Associated with high risk of heart attack |
|
Healthy levels of HDL vs LDL
|
Ideally, HDL >60 mg/dl in blood, less than 40 is considered significant health risk
Ideally, LDL <100 mg/dl in blood, above 130 is considered significant health risk Total cholesterol (HDL + LDL) should be less than 200 mg/dl |
|
About HDL
|
High density lipoprotein (HDL)
made by Liver Transports cholesterol away from cells to liver Removes cholesterol from arteries Made by liver ‘good’ cholesterol |
|
Health effects of lipids:
coronary heart disease ( how does it relate to each |
Positive association with saturated fat
- Some saturated fats raise LDL Positive association with LDL Negative association with MUFA - Monounsaturated fats raise HDL Negative association with PUFA - Omega-3 fatty acids (fish oils) decrease cholesterol reduce blood clotting reduce blood pressure? Positive association with trans-fatty acids Formed in the hydrogenation of vegetable oils (margarine) |
|
what is the recommended fat intake?
|
10% or < of total kcals from saturated
200 mg or < of cholesterol |
|
how are carbs stored?
|
glycogen in muscles
fat |
|
about the adipose cell:
|
loaded with triglycerides
nucleus is being pushed out because there is so much fat |
|
what happens when you loose fat?
|
fat cells diminish in size not quantity so they just shrink
|
|
what do lipase inhibitors do?
|
blocks breakdown of triglyceride in intestinal lumen, inhibiting absorption
|
|
how can you reduce cholesterol?
|
reduce fat consumption
|
|
at what mg level does the benefits of omega 3 max out?
|
800mg
|
|
what is CHD?
|
Any disorder that results from inadequate blood circulation to the heart, impairing heart function.
|
|
what is CVD?
|
Any disorder that results from inadequate blood circulation in heart, brain, neck, and extremities
--often due to plaque build-up and atherosclerosis |
|
how are CHD and CVD related?
|
CHD is a kind of CVD
|
|
what is angina?
|
– chest pain resulting from arteries that are narrowed by 50% or more, reducing blood supply to the heart
|
|
how does plaque start in the arteries?
|
elevated total plasma cholesterol
|
|
what is atherosclerosis?
|
the hardening of the arteries
|
|
what is the cause of atherosclerosis?
|
Elevated blood levels of cholesterol
- Focus on HDL (under 200) vs. LDL (>60) - Role in plaque formation and progression |
|
what are the primary and secondary risk factors for atherosclerosis?
|
Primary risk factors
Smoking (1 or more packs a day) -- veins constricted -- carcinogens promote free radicals that cause micro tears in blood vessels Blood Pressure (diastolic > 90 mm Hg; systolic > 150 mm Hg) Elevated plasma cholesterol (>240-250 mg/dl (can be hereditary) Secondary risk factors Elevated plasma triglycerides Obesity Diabetes Chronic stress |
|
Arteriosclerosis –
|
degeneration of the arteries, resulting in thickening and hardening of the arterial wall
|
|
Atherosclerosis –
|
specific form of arteriosclerosis accumulation of lipids in lesions of intima of large - & medium-sized arteries
|
|
Aneurysm –
|
dilation or ballooning of an artery
|
|
Ischemia –
|
deficient blood supply (angina)
|
|
Infarct –
|
area of coagulation necrosis due to deficient blood supply
- In myocardial infarction (heart attack), part of the heart dies due to inadequate blood flow |
|
Embolus –
|
a plug, composed of a detached clot, mass of bacteria, or other foreign body, occluding a blood vessel.
|
|
Thrombus –
|
a blood clot which more or less occludes an artery or cavity in the cardiovascular system
-heart attack can occur from both thrombus or embolus |
|
Infarct in extremities –
|
gangrene
|
|
Stenosis –
|
the narrowing of a vessel
|
|
Cerebral infarction –
|
stroke
|
|
what are the layers of a blood vessel?
|
endothelial cells - line the inside wall
intima - innermost layer media- all muscle adventitia - needed to make muscle cell in media |
|
what are the good cholesterol levels and risk factors?
|
Cholesterol;Desirable ;Borderline ;High
Total <200 ;200-239; >240 LDL <100 ;130-159 ;>160 HDL >60 <40 --- Triglyceride <150; 150-200 ;>200 |
|
what is the link between Chronic Inflammation and Heart Disease?
|
LDL breakage of endothelial layer can trigger inflammatory response.
Inflammation release a number of factors, among them, free radicals, which are reactive oxygen atoms that lack an electron. These free radicals oxidize LDL. An oxidized LDL more plaque forming than normal LDL since steal electrons from a nearby atom or molecule (oxidation). |
|
Antioxidants –
|
substance that prevent or repair damage to cell cause by exposure to free radicals
|
|
examples of antioxidants
|
Beta-carotene
Vit E Vit C Selenium |
|
about PUFA in our cell membranes
|
double bonds susceptible to oxidation
free radical + FA oxidized FA(reactive) anti oxidants get oxidized instead |
|
what can happen if atherosclerotic plaque builds up?
|
pieces of plaque can break free, travel to the brain and block blood vessels that supply blood to the brain
|
|
TWO main types of Drugs used to combat elevated Cholesterol
|
HMG-CoA reductase Inhibitor - best molecular target of cholesterol in liver
-- target key enzyme in cholesterol synthesis Bile Acid Sequestrants |
|
what does Hepatic synthesis of bile acids do?
|
accounts for the majority of cholesterol breakdown in the body.
|
|
In humans, how much cholesterol is converted to bile acids and eliminated in bile every day.
|
500mg
|
|
Approximately how much bile acid delivered to the duodenum are absorbed back into blood within the ileum.
|
95%
|
|
what do sequestrants do?
|
interfere with the reabsorption of bile acids by the intestine
Enhance conversion of cholesterol into bile acids in the liver Reduce hepatic cholesterol content Enhance the activity of LDL receptors Shifts system toward excretion rather than reabsoption Not as effective as statins |
|
what are the 2 key events that happen for atheroscleratic plaque to form?
|
Endothelial injury
Foam Cell Formation |
|
other risk factors for CVD
|
High Blood pressure
High blood homocysteine degrades and inhibits the formation of the three main structural protein components of the artery, collagen, elastin and the proteoglycans |
|
HOMOCYSTEINE –
|
an “intermediate byproduct” of normal metabolism
|
|
High levels of homocysteine result from what?
|
1) genetic defects, and/or 2) nutritional deficiencies.
|
|
Men and women with high levels of homocysteine have increased risk not only for:
|
1) stroke and
2) heart attack but also 3) osteoporosis, 4) depression, 5) certain types of cancer, and 6) dementia (memory loss and loss of higher brain functions, such as seen with Alzheimer’s disease) |
|
what are foods with little caloric sources can be rich sources of phytochemicals
|
Celery, tea, garlic
|
|
how do phytochemicals work?
|
Hormone-inhibiting substances – prevent cancer initiation
Antioxidants Block harmful enzymes Modify cholesterol absorption, synthesis, and utilization Decrease blood clot formation |
|
what is resveratrol and where can you find it?
|
a phytochemical
skin of red grapes, constituent of red wine |
|
what is a hazardous phytochemicals?
|
ackee fruit
Found in Jamaica, Africa Fleshy part around seed edible Skin, and unripe fruit contain agents that drop blood pressure and blood glucose Can result in immediate death |
|
do vitamins have calories?
|
no, don't break them down for energy
|
|
what do vitamins do?
|
Function as regulators--allow metabolic reactions to occur
Serve as part of a “co-enzyme” non-protein chemical compound that is bound (either tightly or loosely) to a protein (enzyme) and is required for the protein's biological activity. |
|
what is the active site?
|
where compounds will bind to the enzyme in order for them to function
|
|
what is bioavailability?
|
Availability of vitamin in food depends on quantity in food and amount absorbed.
|
|
How is bioavailability determined?
|
Efficiency of digestion and time of transit through GI tract
Previous nutrient intake and status Other foods in meal Method of preparation (raw, cooked, processed) Source of nutrient (synthetic, fortified, naturally occurring) |
|
how can vitamins be damages?
|
Prolonged heating – (thiamin loss)
Can refrigerate most foods UV light – (riboflavin loss) Translucent storage containers Oxygen – (vitamin C) Store cut fruits in airtight wrappers, then refrigerate |
|
when measuring vitamin intake what must be taken into account?
|
both vitamin and provitamin intake must be taken into account.
|
|
what causes vitamin deficiency?
|
Little variety in diet--insufficient intake
Poor intake of vitamin Increased requirement for vitamin illness competing drugs growth, etc. Severe vitamin deficiency is not a big US problem |
|
what nutrients are enriched grains still deficient in?
|
B-6, magnesium and zinc
|
|
what was the point of the enrichment act of 1941 and 1998?
|
increase vitamin b content in foods
|
|
what are the 9 water soluble vitamins
|
B-complex vitamins: B1, B2, B3, B6, B12, folate, biotin, pantothenic acid
Vitamin C |
|
what are the 4 fat soluble vitamins
|
A, D, E & K
|
|
about water soluble vitamins
|
Absorption: Directly into the blood
Transport: Travel freely Storage: Freely circulate in watery area Excretion: Excess removed via urine Toxicity: Possible with supplements Requirements: Frequent doses every 1-3 days |
|
what are the names of b1, b2, and b3
|
Thiamin, Riboflavin & Niacin
|
|
what do the b vitamins do?
|
Function: as coenzymes for energy absorption and utilization
Energy metabolism, nerve cell function must be added to enriched flour by law |
|
what are the deficiencies associated with b1, b2, and b3
|
B1-beriberi; B2-ariboflavinosis; B3-pellagra
lots of effect on nervous system |
|
what are the 3 types of beri beri?
|
Dry BB
- Nervous System Wet BB - Heart & Circulation Wernicke’s – brain/nerves. Often seen in alcoholics, at risk group for thiamin deficiency - excessive alcohol consumption blocks thiamin absorption |
|
what are the main thiamin sources?
|
pork, meat products, fortified grains
|
|
what happens in riboflavin deficiency?
|
No one disease associated with deficiency
General inflammation of the mouth, skin, GI tract |
|
what is a great riboflavin food source?
|
liver
|
|
what happens in niacin deficiency? how can it be prevented?
|
Pellagra
Diarrhea, Dermatitis, Dementia, (Death) Occurs in 50-60 days Decrease appetite & weight Prevented with an adequate protein diet Only dietary deficiency disease to reach epidemic proportions in the U.S. in the 20s and 30s - prompted acts of congress in '41 to enrich foods |
|
what is the name of b6 and what is it's function?
|
Pyridoxine
Function: protein and amino acid metabolism neural function conversion of tryptophan to niacin conversion of tryptophan to serotonin |
|
what happens in b6 deficiency?
|
Deficiency: anemia, muscle weakness, depression, confusion
|
|
what happens in b6 toxicity?
|
Toxicity: first reported 1983: 2 grams/day supplement for 2-3 months.—nerve degeneration
|
|
what does folic acicd do? what is the current recommendation?
|
Functions:
production of red blood cells; protein synthesis Synthesis of nucleotides to make DNA Prevents neural tube birth defects; maintains normal homocysteine level Current recommendation: Women should take folic acid supplements when they want to become pregnant, as well as during pregnancy |
|
what happens in folate deficiency?
|
Heart Disease & hyperhomocysteinemia
Megaloblastic Anemia Neural Tube Defects Similar signs and symptoms of vitamin B-12 deficiency |
|
what happens in megaloblastic anemia?
|
due to folate or vitamin b12 deficiency red blood cells are unable to divide. so they stay in an early stage of development, keep their nuclei and are slightly larger than normal red blood cells.
|
|
what are the causes of folate deficiency?
|
Poor diets
poor & elderly Pregnant women – increased requirements Alcoholics Anticancer/ RA drug methotrexate |
|
what is the neural tube?
|
the embryo's precursor to the central nervous system, which comprises the brain and spinal cord
|
|
what happens in spina bifida?
|
th eneural tube has failed to close near the base of the spine
|
|
what is anencephaly?
|
the brain is absent or very poorly developed
|
|
what is encephalocele?
|
the brain is protruding through an opening in the skull.
|
|
what are the food sources of folate?
|
Liver
Fortified breakfast cereals Grains, legumes Foliage vegetables Susceptible to heat, oxidation, ultraviolet light |
|
what is the name is vitamin b12 and what is its function, deficiency and sources?
|
Cobalamin
Function: red blood cell, Nerve tissue production Deficiency: Megaloblastic Anemia similar to folate, it is also characterized by large immature cells neurological disorders – including neurodegeneration Source: animal products and fortified grains Absorption can be problem in elderly--take B12 shots |
|
what are the 2 ways to have deficiency of b12?
|
Dietary Deficiency
Megaloblastic Anemia, similar to folate, it is also characterized by large immature cells Atrophic Gastritis Condition common in older people, cells of stomach damaged Normally, stomach cells release Intrinsic Factor (IF) with HCL which binds VitB12 and releases it from proteins in foods undergoing digestion VitB12 not easily absorbed into blood without being bound to IF If stomach cells damaged due to Gastritis, too little IF released. Resulting Megalobastic Anemia due to B12 deficiency in patients with Gastritis termed to have Pernicious Anemia |
|
how can you differentiate vit b12 and folate deficiency?
|
Vitamin B-12 deficiency is usually accompanied by elevated concentrations of blood homocysteine and methylmalonic acid.
Folate deficiency results in only elevated homocysteine. Also test for Intrinsic Factor in blood |
|
what is the name of vitamin c, can we synthesize it and what conditions are related with its deficiency?
|
Ascorbic Acid/ Anti-Scorbutic Vitamin
Synthesized by most animals not by humans Deficiency- Scurvy, dermatitis |
|
what are the functions of vit c?
|
Collagen synthesis (main protein of connective tissue) - if not then you bruise easily
Reducing agent (antioxidant) Enhances Iron absorption Synthesis of neurochemicals, steroids, cholesterol to bile acids (the enzyme that does this requires vit c) Immune functions Cancer prevention? |
|
what happens in vit c toxicity?
|
Possible with Supplements (greater than 10x the upper limit)
Tendency toward Gout Kidney stones Pro-oxidant Cramps, nausea, diarrhea |
|
about fat soluble vitamins
|
Absorption: Lymph then blood
Transport: Many need protein carriers Storage: In fat cells Excretion: Tend to remain stored Toxicity: Likely with excessive intake/supplements Requirements: Periodic doses (Weeks- months) |
|
what prefic denotes vit a? what are the different forms of vit a?
|
retin-
retinol (alcohol) retinal (aldehyde) retinoic (acid) |
|
what is rhodopsin?
|
- (Opsin + Retinal)
- Responsible for black and white vision - Located in the rods - Night vision |
|
what is iodopsin?
|
- Contains Retinal
- Responsible for color vision - Located in the cones - Day and color vision |
|
what are the rods and cones responsible for in the eye?
|
rods - night
cones-day/color |
|
what are more functions of vit a?
|
Maintains mucus-forming cells throughout the body
- Produce mucopolysaccharides - Act a lubricants and protects against infections - Found in eyes, lungs, GI tract, etc. Maintains epithelial cells (skin...) Growth (retinoic acid) - normal bone growth - tissue growth Immune function Cancer prevention ? - cancer involving epithelial cells - beta-carotene acts as antioxidant to trap free oxygen radicals |
|
what happens in vit a deficiency?
|
Night blindness
Permits early deficiency diagnosis The eyes slow to recover in response to flash of bright light Blindness (xerophthalmia) Caused by severe Vit-A deficiency Cornea becomes dry and hard, then soft (irreversible) Keratinization Epithelial cell secretes Keratin (found in hair and nails) Skin becomes hard, rough, and scaly Infectious Disease Measles, Malaria susceptibility enhanced with Vit A deficiency Widespread initiatives, supplement infrequent mega Vit-A doses |
|
what happens in vit a toxicity?
|
Birth defects; liver damage; hair loss
Toxic only by supplementation, not food Vit A is toxic but not beta-carotene Carotene from food stored in fat tissue. May turn skin orange, but this is cosmetic, and not harmful. From supplement, may act as Pro-Oxidant in very high levels |
|
what is the name of vit d and how is it synthesized?
|
calciferol
Synthesized in skin when exposed to sunlight From U.V. irradiation of skin Possible for adult to synthesize requirement, different from all other nutrients Acts like a hormone Controls cellular functions |
|
what is the function of vitamin d?
|
Function in Calcium balance: blood Calcium
absorption in small intestine calcium deposition in bone for mineralization and strengthening urinary calcium re-absorption by kidney |
|
what happens in vit d deficiency and toxicity? what are food sources?
|
Deficiency:
Rickets in children Loss of Calcium in bone leads to osteoporosis in adults Toxicity in excess – supplements can alter calcium concentrations in blood and bone Few food sources Fortified milk, butter/margarine, Liver Sunlight activates precursor in skin |
|
what is the name of vit e and what is the function and food sources?
|
tocopherol
Function as antioxidant Foods: protects against rancidity(oxidation of food) Body: protects from “free radical damage” to cells and tissues; prevents artery plaque formation Food sources Nuts, seeds, wheat germ, whole grain Veg oil, marg, mayo & salad dressing |
|
what is the function and food sources vit k?
|
Function: blood “K”oagulation
Synthesized by colonic bacteria in GI tract Food sources--leafy green veg |
|
what happens in vit k deficiency and toxicity?
|
Deficiency: abnormal blood clot; bruise easily
Long term use of antibiotics Hemorrhage common in infants b/c little synthesis (sterile GI tract at birth) Toxic only with excess synthetic supplements |
|
what is an antioxidant? examples?
|
substance that prevent or repair damage
Beta-carotene Vit E Vit C Selenium |
|
what is the most abundant mineral in the body? where is it found?
|
calcium
99% in bones/teeth Bone structure- rigid frame to hold body upright, attachment of muscles Serves as a calcium bank, readily available source to fluids of the body if blood calcium drops Hydroxyapatite- Calcium and Phosphate crystals (seen in bone deposition) Mineralization- crystals become denser, strengthening and providing rigidity to maturing bone Bones constantly gaining and losing minerals continuously …NOT inert like a rock! Balance of the two Fluoride stabilizes and hardens teeth, opposing mineral withdrawal (different from bone) 1% in blood and soft tissues Blood clot formation/blood pressure Nerve impulse transmission Muscle contraction Enzyme regulation Blood level is maintained at the price of bone calcium |
|
about minerals and their varied roles
|
Inorganic Elements (do not contain carbon)
Unlike vitamins, which are large molecules, are easily damaged/destroyed, mineral atoms always retain their chemical identity. No destruction by heat, air, acid, mixing Carry a charge, meaning they are “ions” Positive charge- Cation, Negative- Anion May be easily absorbed or require carriers Water soluble Fat soluble Bioavailability variation, similar to vitamins Interactions Excess of one mineral can create inadequacy of another (Na/Ca , Mg/K) Varied roles Fluid Balance (sodium, potassium, chloride) Growth and health (calcium, phosphorus, magnesium) |
|
what happens when blood calcium rises?
|
thyroid glad is signaled to secrete calcitonin => calcitonin does the following things:
inhibits the activation of vit d; prevents calcium reabsorption in the kidneys, limits calcium absorption in the intestines; inhibits osteoclast cells from breaking down bone, preventing the release of calcium |
|
what happens when blood calcium level falls?
|
signals the parathyroid glands to secrete parathyroid hormone. This hormone in turn...
stimulates the activation of vit D vit d and the hormone stimulate calcium reabsorption in the kidneys vit d enhances calcium absorption in the intestines vit d and parathyroid hormone stimulate osteoclast cells to break down bone, releasing calcium into the blood |
|
what are osteoblasts?
|
deposits calcium in bones
|
|
when is the peak bones mass?
|
in the 20s
|
|
what happens in calcium deficiency?
|
osteoporosis - holes in bones
|
|
what is the adequate intake of calcium and the toxic amount?
|
AI: 1000 -1200 mg/day for adults
AI: 1300 mg/day for adolescents (9-18 yrs. old) Actual intake range from 600-800 mg/day for women and 800-1000 mg/day for men Many are slightly deficient toxic: 2.5 g/day – deposits in kidney and liver |
|
about sodium: functions, requirement??
|
Major cation of extracellular fluid
Movement into cell initiates action Est. min. requirement = 500 mg/d Should consume < 2300 mg/d Functions: Maintains electrolyte balance Nerve impulse transmission Muscle contraction |
|
what happens in sodium deficiency?
|
Sodium Deficiency
(Hyponatremia) Symptoms Muscle cramps Mental apathy Loss of appetite |
|
what happens in sodium toxicity?
|
Sodium Toxicity
(Hypernatremia) Symptoms Edema Acute hypertension Usually not a problem if H2O is adequate |
|
what is hypertension?
|
= high blood pressure
medical condition in which the blood pressure is chronically elevated. Sodium environmental factor given much attention. ~1/3 hypertensive population is responsive to sodium intake. increasing salt in a person's bloodstream causes cells to release water (due to osmotic pressure) to equilibrate the concentration gradient between the cells and the bloodstream This increases pressure within the blood vessel wall Increases thirst Increase retention of water by kidneys |
|
about chloride?
|
Major anion in extracellular fluid
HCl in stomach - Protein digestion Lose HCl through vomiting pH = Metabolic alkalosis Abundant (esp. NaCl), no RDA |
|
about potassium?
|
Principal cation inside all living cells
Fluid balance Nerve transmission Muscle contractions (same as sodium) Best source: whole & fresh foods fruits and vegetables K diet blood pressure |
|
about phosphorus?
|
85% with Ca in hydroxyapatite crystals (bone & teeth)
Energy Metabolism - ATP, many enzymes and B vitamins are “phosphorylated” Phospholipids - lipid carrier, cell membranes DNA, RNA Buffer system for acid-base balance w/o phosphorus there no ATP |
|
about magnesium?
|
Bone Mineralization & teeth (~50% of body MG)
Enzymes Muscle contraction and nerve conduction Antagonistic to Ca Ca stimulates contraction Mg++ relaxes muscles Regulates b.p., lung function Important for heart function |
|
about processed foods?
|
Processed foods - biggest contributor to Na+ in our diet
Foods that have Na added may not taste salty. Na+ bicarbonate (baking soda) Na+ saccharine (artificial sweetener) As Na+ content through processing, K+ Can impair fluid balance in tissues (Na/K relationship) |
|
what are the two ionic states of iron?
|
ferrous iron (reduced)
ferric iron (oxidized) |
|
where can most iron be found in the body?
|
Hemoglobin in RBC carries O2 and CO2 (80% of body iron)
Myoglobin in muscles stores O2 So, in both, Fe helps accept, carry and release oxygen |
|
what is hemoglobin?
|
Oxygen containing protein of RBCs that transports oxygen from the lungs to body tissues
Myoglobin is oxygen-holding protein in muscle |
|
what is ferritin?
|
protein that receives Iron from food in intestine, and stores iron in mucosal cells lining SI.
|
|
what are transferrins? what are the 2 types?
|
protein that transports iron
mucosal and blood transferrin |
|
what is heme and non heme iron? where do you get it?
|
heme: the iron holding structure within the hemoglobin and myoglobin proteins
- only foods derived from animal flesh provide heme, also contain non heme iron all iron in foods derived from plants is nonheme heme accounts for 10% of the average daily iron intake (25 absorbed) non heme is the remaining 90%, but only 17% is absorbed. w/o heme iron can't bind to red blood cells |
|
what is hemosiderin?
|
Iron storage protein primarily made in time of iron overload
secondary storage mechanism if excessive amount of iron then there will be lots of hemosiderin/ alerts to iron toxicity |
|
what are the different types of iron deficiency?
|
Iron deficiency- initial stages
Ferritin levels decrease (stored iron), transferrin increases (form in transport) Iron deficiency w/o anemia ‘Tired tissues’ Enzymes don’t perform efficiently Iron deficiency w/ anemia Severe depletion of Fe stores Low hemoglobin concentrations Microcytic, hypochromic anemia – small / pale red blood cells – lower iron levels – reduced Oxygen carrying capabilities |
|
what is hemochromotosis ?
|
Common genetic disorder failing to prevent unneeded iron from being absorbed.
1.5 million in U.S. |
|
who needs more iron and when?
|
WOMEN DURING REPRODUCTION
MENSTRUATION PREGNANCY INFANTS YOUNG CHILDREN ADOLESCENCE - MALES-RAPID GROWTH - FEMALES MENSTRUAL LOSSES BLOOD LOSSES (ULCER, INFECTIONS) |
|
what are the roles of zinc in the body?
|
- Important in many enzyme systems
genetic materials digestive enzymes heme synthesis essential fatty acid - Metabolism CHO metabolism Protein synthesis Metabolism of alcohol Free radical disposal |
|
how much zinc is absorbed and how is it stored?
|
15-40% absorbed
stored by metallothionein - similar to ferritin for iron |
|
what is zinc's interaction with iron?
|
easily confused for by the proteins thats bind them
High zinc causes low Fe absorption Similar metals, both +2 charge Can bind w/ transferrin --> decreases iron absorption High Fe intakes cause low Zn absorption Similar effects with Zn and Copper as well Copper is +2 if there is excessive zinc intake it will bind to albumin and transferrin so there will be less iron intake or vice versa |
|
what happens in zinc deficiency? toxicity?
|
Poor growth
Inadequate sexual development Reduced sense of smell and taste Acne-like rash Mental confusion Lack of appetite toxcitity Small doses Over time can affect the heart (interfere with copper) Larger doses diarrhea, vomiting, fever, anemia, exhaustion Related to overuse of supplements |
|
what is the function of iodide?
|
Part of thyroid hormones - Thyroid hormones control BMR
|
|
what happens in iodide deficiency?
|
Goiter
low Iodide intake (simple goiter) high goitrogen intake (toxic goiter) thyroid antagonist, interferes with I absorption “Goitrogens” found in cabbage, cauliflower, broccoli, brussel sprouts (few others) Can cause: Sluggishness Weight gain Cretinism Iodine deficiency in-utero Severe mental retardation Result of I deficiency, or malfunction of thyroid gland |
|
what is the most common cancer death for women?
|
lung
|
|
what is cancer?
|
A group of diseases in which abnormal cells grow out of control and can spread throughout the body.
Second leading cause of death behind cardiovascular disease. “mitosis (cell division) out of whack” |
|
what is apoptosis?
|
normal destruction of cell by body due to damage, some other abnormality
- if it escapes destruction and continues to divide then that can develop into cancer |
|
what are the diff kinds of cancer?
|
carcinoma - most common; arise from cells that cover external and internal body surfaces,
ex. lung breast, colon sarcoma - cells found in supporting tissues such as bone, cartilage, fat, connective tissue, and muscle lymphoma- arise in lymph nodes and tissues of body's immune system lukemia - cancer of the immature blood cells that grow in bone marrow and tend to accumulate in large numbers in the bloodstream melanomas - abnormally dividing skin cells |
|
what are the 3 steps of cancer growth?
|
Initiation: start of the cancer process, which begins with alteration of DNA within the cells.
Promotion: The period in cancer development when the number of cells with altered DNA increases. Progression: Uncontrolled growth and spread (metastasis) of cancer cells. |
|
what is p53
|
p53: “tumor suppressor” gene
activates DNA repair proteins when DNA has sustained damage. can initiate apoptosis, the programmed cell death, if the DNA damage proves to be irreparable. |
|
what happens when something goes wrong with p53
|
Inactivation of the p53 tumor suppressor gene through mutation by environmental factor is a common event in the development of colon cancer
Risk factors for p53 mutation: Physical inactivity large body mass index cigarette smoking Western-style diet such as high consumption of red meat and simple sugars |
|
what is superoxide dismutase?
|
Natural enzyme found in cells that prevents free radical damage
Functions as antioxidant Superoxide is an anion, lacking one electron is a free radical With help of Fe or Cu as coenzymes, SOD “dismutates” superoxide radicals into oxygen and hydrogen peroxide Increases stability, naturally prevents cancer initiation from propagating |
|
what do cells classify as cancer cells
|
beginning with the progression stage
|
|
what are the mandatory parameters of cancer stages?
|
Mandatory parameters ('T', 'N', and 'M')
T (0,1-4): size or direct extent of the primary tumor N (0-3): degree of spread to regional lymph nodes N0: tumor cells absent from regional lymph nodes N1: tumor cells spread to closest or small number of regional lymph nodes N2: tumor cells spread to an extent between N1 and N3. N3: tumor cells spread to most distant or numerous regional lymph nodes M (0/1): presence of metastasis M0: no distant metastasis M1: metastasis to distant organs (beyond regional lymph nodes) |
|
What are the different stages of cancer?
|
Stage 0 carcinoma very localized (no potential for metastasis, early cancer that is present only in the layer of cells in which it began)
Stage I cancers are localized to one part of the body. Stage II cancers are locally advanced. Stage III cancers are also locally advanced. Whether a cancer is designated as Stage II or Stage III can depend on the specific type of cancer The specific criteria for Stages II and III therefore differ according to diagnosis. Stage IV cancers have often metastasized, or spread to other organs or throughout the body. |
|
about benign tumors?
|
not cancerous.
can usually be removed do not come back in most cases do not spread to other parts of the body and the cells do not invade other tissues Doesn’t mean not dangerous! |
|
about malignant tumors?
|
cancerous.
can invade and damage nearby tissues and organs metastasize (cancer cells break away from a malignant tumor and enter the bloodstream or lymphatic system to form secondary tumors in other parts of the body) |
|
what is endometrial cancer?
|
cancer of the lining of the uterus - related to inherited factors
|
|
what does the cancer drug cisplatin do and what cancers is it used for?
|
inhibits division of rapidly dividing tumor cells
Sarcomas – cancer of connective tissues Carcinomas -- cancer of epithelial cells -- e.g., lung and ovarian cancers Lymphomas - cancer made in the lymph nodes and tissues of the immune system Leukemias - cancers of the immature blood cells that grow in the bone marrow and tend to accumulate in large numbers in t he bloodstream |
|
how is diabetes mellitus characterized?
|
mainly characterized by chronically high blood glucose
|
|
what are the normal functions of insulin?
|
Hormone produced by the Beta cells of Pancreas
regulates the blood glucose level in the body along with Glucagon converts free glucose to glycogen and stores it in the liver (and other muscle tissue) Controls food intake and energy balance |
|
what comes from the alpha and beta cells of the pancreas?
|
Glucagon
from alpha cells increase blood glucose Insulin from beta cells decrease blood glucose |
|
what happens when there is low blood glucose?
|
glucagon released from pancreas and liver releases glucose into blood
|
|
what happens when there is high blood glucose?
|
insulin released by beta cells in pancreas and fat cells take in glucose from blood
|
|
what does hyperglycemia lead to?
|
Increased blood triglycerides
Atherosclerosis Chronic inflammation |
|
About IDDM (type I)
Insulin Dependent Diabetes Mellitus |
No, or very little, insulin produced by beta cell
5-10% of total DM cases Juvenile Onset Immune – mediated Idiopathic (unknown cause) Viral infection early in life Genetic destruction of part of pancreas |
|
About NIDDM (type II)
Non-Insulin Dependent Diabetes Mellitus |
Insulin resistance
Insulin receptor and post-receptor defects Onset from childhood up Common in advance stage of multiple diseases Obesity most important environmental determinant in manifestation Risk increased 10 fold Increased glucose intolerance and hyperinsulinemia Associated to visceral fat |
|
about type 1 diabetes
|
Food enters GI tract, CHO converted to monosaccharides (free glucose)
Glucose absorbed, enters bloodstream Pancreas does not respond to increased glucose – beta cells make little/no insulin Little or no insulin in bloodstream Glucose builds up in bloodstream |
|
about type 2 diabetes
|
Food enters GI tract, CHO converted to monosaccharides (free glucose)
Glucose absorbed, enters bloodstream Pancreas makes insulin Insulin enters bloodstream Insulin signaling at receptor impairing, glucose cannot enter cell, glucose in bloodstream builds up Insulin Resistance |
|
what are the symptoms of diabetes?
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Shows symptoms of diabetes (polyuria, polydipsia, unexplained weight loss) and has a blood glucose concentration (at any time of day, regardless of meal time) ≥200 mg/dL.
Polyuria – excessive urine Polydipsia – excessive thirst A glucose concentration after at least 8 hours of fasting ≥126 mg/dL. Plasma glucose concentration ≥200 mg/dL two hours after an oral intake of 75g glucose dissolved in water. Oral Glucose Tolerance Test (OGTT) |
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what are the causes of insulin resistance?
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Abnormal ß-cell secretory product (non func)
Abnormal insulin molecule Incomplete conversion of pro-insulin to insulin Circulatory Insulin immune response Anti-insulin antibodies Anti-insulin receptor antibodies Target tissue defects - decreased receptors on cell Insulin receptor defect Post-receptor defects |
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What is HA1C?
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Hemoglobin- A1C
A.K.A HbA1c or A1C measured in people with diabetes to provide an index of average blood glucose for the previous three to four months. glucose attached to hemoglobin, HEMOGLOBIN- protein in red blood cells that transports oxygen A1C is hemoglobin that has been glycosolated. It is sometimes referred to as glycosolated hemoglobin A1c or glycohemoglobin. The glucose in A1C is irreversibly bound to hemoglobin. Glucose binds to hemoglobin continuously throughout the lifespan of the red blood cell. (120 DAYS) |
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what is the normal level of A1C
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The normal level of A1C in people without diabetes is approximately 4% to 6%.
1% A1C corresponds to approximately 35 mg/dl blood glucose |
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why does the level of A1C increase or decrease relatively quickly with large changes in blood glucose?
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blood glucose levels in the preceding 30 days contribute substantially more to the level of A1C than do blood glucose levels 90 to 120 days earlier.
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how does diabetes cause blindness?
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eyes are highly vascularized
- high glucose leads to spontaneous micro aneurysms which lead to large hemorrhages in the eye |
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dietary recommendations for diabetics
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proteins
ADA recom: 10-20% of energy needs Diabetics: 10 to 15% Excessive protein – diabetic nephropathy (should not exceed 15% as energy) fat Should not exceed 30% of energy Saturated fats – 10% Polyunsaturated fats under 10% Increase monounsaturated (canola, olive oils) Cholesterol – 200 mg/day |
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what is the Drug Treatment of Choice for IDDM?
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Insulin
Now rare for people to have antibodies to insulin on the market (recombinant DNA) Hypoglycemic drugs **Sulfonylureas Increase sensitivity to glucose in ß-cells They produce more insulin 30-50% of Type II are managed by these drugs Advantages: - Oral - less risk of becoming hypoglycemic **Thiazolidinediones (TZDs) Increase sensitivity of insulin receptors to insulin Pancreatic cell transplantation: Implant functional beta cells All human trials have failed after 2.5 years Exercise Essential for Type I and Type II Moderate levels increase Rate of glucose uptake Has a direct influence on: - CV performance - glucose clearance |
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what is the nutrient needed more than others
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water - 6th nutrient class
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what is hydrostatic equilibrium?
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intake=output
body maintains this through water intake |
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what are the %s of water in diff parts of the body?
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Water ~ 60% of normal adult body weight
More in children, less as %age in obese Muscle tissue - 75% H2O Fat cells - 10% H2O Body water content inversely related to body fat Make sense? |
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what is the recommended water intake
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The AI for total water intake for young men and women (age 19 to 30 years) is 3.7 L and 2.7 L per day, respectively
In NHANES III, fluids (drinking water and beverages) provided 3.0 L (101 fluid ounces; ~13 cups) and 2.2 L (74 fluid ounces; ~9 cups) per day for men and women age 19 to 30, representing approximately 81 percent of total water intake. Water contained in food provided about 19 percent of total water intake. 1.0-1.5 ml/kcal expended (Adults) 1.5 ml/kcal expended (Infants) liter = 4.2 cups cup 8 oz. |
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what does bottled water lack?
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fluoridation
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What comprises the daily obligatory water loss?
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insensible loss (skin evaporation, respiration): 800 mls
minimal sweat loss: 100 mls fecal loss: 200 mls minimal urine volume: 500 mls can vary from ~1450-2800 ml (6-11 cups) |
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what are the functions of water in the body?
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Transports nutrients & waste products
Regulates body temperature Medium for chemical reactions Required for energy formation - gluconeogenesis- requires water Lubricant, Cushion, etc. |
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what are the fluid compartments in the cell?
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Intracellular - fluid within the cell
Intercellular/interstitial- fluid between the cells Intravascular- fluid within the blood vessels blood: plasma - 90% |
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how is water movement controlled?
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tightly controlled by solute to solvent ratio. osmotic pressure - moves water across a membrane when solute concentrations are not equal
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what are some electrolytes and what do they do?
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sodium, chlorine, potassium, calcium
they attract water cells move electrolytes in and out |
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how are sodium and chloride most easily lost
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- Vomiting
- Diarrhea - Sweating - Bleeding |
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A 1-liter preparation of ORT solution contains what?
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sodium chloride (NaCl) - 2.6g
trisodium citrate dihydrate - 2.9g potassium chloride (KCl) - 1.5g anhydrous glucose - 13.5g |
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what is thirst?
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brain perception of dip in blood pressure and volume
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how does the body respond to thirst?
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sends out antidiuretic hormone
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what is the hypothalamus and what does it do?
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Region in the brain with major control of food/water intake
Releases ADH - Antidiuretic Hormone Anti = against di = through ure~ = urine Kidney reabsorbs H2O |
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what are osmoreceptors?
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thirst sensors
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how long can you last without water
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3 days
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what happens in dehydration as your % body weight loss
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1-2% = thirst
3-4% = muscular strength + endurance physical performance 5-6% = heat intolerance + very weak 7-10% = coma & death |
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what happens when muscles cell size increases?
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increased strength
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what is the difference between dark muscle and white muscle?
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dark - endurance
white - fat moving, less used muscle |
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what is myostatin?
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hormone that limits muscle growth
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what is VO2max
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maximum oxygen volume utilization
Measure cardiorespiratory fitness Max. O2 uptake or consumption during max. aerobic metabolism 100% VO2 max not sustainable Training at 40-60% of max at first, can improve to 70-85% over time |
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what is maximal heart rate
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Heart rate where highest level of oxygen consumed.
Roughly equal in intensity to VO2 max |
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Calculate Target exercise heart rate:
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(220-AGE) x %MHR=
% MHR = % intensity of exercise in reference to maximum heart rate (220-29) x .80 = 153 |
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what is the best nutrient source for low and intermediate intensity sports?
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fatty acids
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what is the only significant food that provides energy without oxidative metabolism (AA’s and fat both oxidized)
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CHO - Carbs
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how much glycogen can our muscles store?
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0.5-2.0g/100g muscle
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what is glycogen loading?
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60-70% cal from CHO 3 days prior to event, 20 min/day training 1st and second day, rest on third day
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what should be in pre-event meals?
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complex CHO, low fat, fruits, veggies, and fluids, low fiber!
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what is oxygen debt?
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lactate buildup
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how do you get maximum glycogen stores?
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Eat high CHO diet regularly (70% of kcal)
Eat snacks containing glucose during event. Eat CHO foods following exercise. Within 15 min., 300% in storage efficiency of glycogen storage Train regularly. glycogen storage O2 efficiency can use more fat for energy |
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endurance athletes need to consume how much energy from fat?
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20-30%
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protein should comprise how much of energy?
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10%
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how much protein is needed for remodeling and building muscle?
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~15 g protein to existing muscle mass / day during building periods
May go as high as 45g of protein to muscle at max |
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what comprises dark meat?
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mitochondria and myoglobin
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what is hyponatremia?
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diluted blood sodium level
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