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63 Cards in this Set

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Whats the most obese region of Canada?
The Maritimes
Why is obesity increasing?
1. marketing
2. automation (we don't have to move as much.. think of a secretary emailing her boss rather than getting up to go deliver a memo)
3. Lifestyle (sedentarianism)
4. fast food
and many, many more reasons
Health Risks of being overweight:
1. Hypertension (50% of cases)
2. Diabetes (3X risk)
3. Heart Disease
4. joint problems
among many more

*As of now, only tobacco contributes to more preventable diseases and premature deaths
Social and Economic costs of obesity:
1. Fat people are more likely to be judged on their appearance than on their character

2. Our society places enormous value on thinness, especially for women (Fat people are less sought after for romance, less often hired, less often admitted to college, pay higher insurance premiums, pay more for clothing)

3. Obese people suffer emotional pain when treated with hostility and contempt
What determines a healthy body weight?
1. Body weight within suggested range for height

2. Fat distribution associated with a low risk of illness and premature death

3. A medical history free of risk factors associated with obesity (including family history)
What IS a healthy body weight?
Both underweight and overweight pose health risks.

lots of factors contribute... there is no such thing as "ideal weight"
Risks from being underweight:
Higher risk of dying from: a siege or famine, when hospitalized, when fasting required for tests/surgery, when fighting a wasting disease (people with cancer often die from starvation)

* Underweight people should gain body fat as an energy reserve and acquire reserves of nutrients that can be stored
Android vs. Gynecoid Obesity:
Android = central obesity (apple shaped)
-correlated to increased risk of heart disease, stroke, hypertension, diabetes
-more common in men and in post-menopausal women

Gynecoid Obesity = Lower Body Obesity (pear-shaped)
-fewer associated health risks
-more common in pre-menopausal women
-fat pattern influenced by estrogen and progesterone
Essential fat vs Non-essential fat:
Essential Fat: necessary for normal body functioning (In nerves, brain, heart, lungs, liver, mammary glands, hormones)
~3% in men
~12% in women

Non-essential (storage) Fat:
-adipose tissue (subcutaneous and visceral)
-accumulates when energy in exceeds energy out
-
Which poses more of a threat to health: visceral fat or subcutaneous fat?
visceral fat is more easily mobile in the blood stream so it is more dangerous than subcutaneous fat
Lean mass vs. Fat mass:
Lean Mass:
-bone
-organs
-muscles
-blood, fluids

Fat Mass:
-subcutaneous fat
-visceral and intramuscular fat
Average body composition of men and women:
Women:
36% muscle
24% organs
27% fat
13%bone

Men:
45% muscle
25% organs
15% fat
15% bone
At what percentage of fat is there increased health risk in men and in women:
men > 22% fat
women > 32% fat
Measuring Body Composition:
1. Underwater Weighing: muscle has a higher density than fat (People with more fat float more and weigh less underwater)

2. Air Displacement: Bodpod - % body fat is calculated from how much air is displaced.

3. DEXA: Measures bone mineral density, lean mass, and by subtraction, fat mass

4. Skin Fold Thickness: Measurements are used in regression equations that have been determined from human cadavers (accuracy is dependent on the skill of the tester)

5. Bioelectric Impedance: A small electric current is passed through the body. Fat cells offer higher resistance to current compared to other tissue.
BMI
BMI = weight (kg) / height (m) squared
BMI Classifications:
<18.5 = underweight
18.5 - 24.9 = normal
25 - 30 = overweight
30 - 34.9 = class I obese
35 - 35.9 = class II obese
>40 = class III obese
Does BMI apply to atheltes?
no Ronnie Coleman (ain't nothin but a peanut) has a BMI of >40 but is in fantastic shape (8 consecutive Mr. Olympia's) and ballet dancers are often <18.5 but are healthy
Waist Circumference:
-Reliable predictor of fat distribution and abdominal fat

-Take measurement around the abdomen, just above the iliac crest

-Significantly increase to the risk of health problems associated with central obesity if
> 40 inches for men
> 35 inches for women
Energy Balance:
Positive Energy Balance: energy in > energy out = weight gain

Negative Energy Balance: energy in < energy out = weight loss
Energy Requirements with age:
Older people need less energy then younger people (Due to a slower metabolism and reduced muscle mass, which are in part due to decreased physical activity)

*On average, energy need diminishes 5%/decade beyond the age of 30 years
BMI Classifications:
<18.5 = underweight
18.5 - 24.9 = normal
25 - 30 = overweight
30 - 34.9 = class I obese
35 - 35.9 = class II obese
>40 = class III obese
Does BMI apply to atheltes?
no Ronnie Coleman (ain't nothin but a peanut) has a BMI of >40 but is in fantastic shape (8 consecutive Mr. Olympia's) and ballet dancers are often <18.5 but are healthy
Waist Circumference:
-Reliable predictor of fat distribution and abdominal fat

-Take measurement around the abdomen, just above the iliac crest

-Significantly increase to the risk of health problems associated with central obesity if
> 40 inches for men
> 35 inches for women
Energy Balance:
Positive Energy Balance: energy in > energy out = weight gain

Negative Energy Balance: energy in < energy out = weight loss
Energy Requirements with age:
Older people need less energy then younger people (Due to a slower metabolism and reduced muscle mass, which are in part due to decreased physical activity)

*On average, energy need diminishes 5%/decade beyond the age of 30 years
3 components of energy output:
1. Basal Metabolic Rate: Sum total of energy expended on all of the involuntary activities needed to sustain life (excludes digestion)

2. Voluntary Activities

3. Thermic Effect of Food: 5%-10% of a meal’s energy is expended in stepped-up metabolism in the 5+ hours after a meal
DRI method for calculating EER:
men: kg body weight x 24 kcal / day
women: kg body weight x 22 kcal / day
Basal Metabolism:
Energy needed to maintain life when the body is at complete digestive, physical, and emotional rest

Includes maintaining:
-body temp
-breathing
-activity of the heart

*largest component of energy expenditure.. can be calculated using the Harris-Benedict equation
Hunger:
The physiological drive for food that initiates food seeking behaviors

Influenced by:
-Nutrient levels in the blood
-Size and composition of the preceding meal
-Nutrients in the digestive system
-Climate
-Exercise, sex hormones, illness, etc.\

* It is also triggered by chemical messengers acting on the hypothalamus

Occurs roughly 4-6 hours after eating (After the food has left the stomach and much of the nutrient mixture has been absorbed)
What contributes to the feeling of hunger?
1. contraction of the empty stomach
2. empty small intestine
3. the stomach hormone ghrelin released between meals
4. chemical and nervous signals in the brain
Accommodation of the stomach:
Just as the stomach can adapt to small meals it adapts to larger quantities of food

-this partly explains the increase in obesity: we are given larger portions, we eat what is on our plate, our stomach gets used to this amt and that is now the norm.
Appetite:
-An integrated sensory response to the sight, smell, thought or taste of food also initiates eating
-it can be experienced w/o hunger
-It is also influenced by emotions, stress, etc…
Satiation:
STOP signal:
-This can be defined as the feeling of satisfaction and fullness that occurs during a meal and usually halts eating
-It determines how much food is consumed during a meal
-It is influenced by receptors in the stomach that are activated by stretch or the presence of food
-This triggers release of hormones that signal the hypothalamus
Satiety:
The feeling of satisfaction and fullness that occurs after a meal and inhibits eating until the next one

Determines how much time passes between meals

Also influenced by the presence of nutrients in the blood
What are some more satiating foods? some less satiating foods?
More: boiled white potatoes, baked fish, oatmeal w/ milk

Less: chips, ice cream, chocolate bar, cake, croissant
Energy cost of digesting, absorbing, and metabolizing:
1. proteins
2. carbs
3. fats
1. proteins: 23%
2. carbs: 6%
3. fats: 3%

“Protein not only increases energy expenditure but also decreases energy intake through mechanisms that influence appetite control”
Protein and the glycemic index:
Adding proteins to meals decreases the glycemic index (potential benefits for glucose tolerance and insulin sensitivity)
The female athlete triad:
1. amenorrhea
2. disordered eating
3. osteoporosis

(Especially prevalent in aesthetic sports (gymnastics, ballet) and endurance sports)
Eating Disorders (overview)
85% of eating disorders start in adolescence

1/2 girls and 1/5 of boys in middle school through high school have an eating disorder

Causes:
-outside pressure (coaches, media)
-emotional/psychological
-sexual abuse
-family life
How are male athletes susceptible to weight-gain problems?
Athletes with well-muscled bodies see themselves as underweight and weak
-frequent weighing
-excessive exercising
-overuse of special diets or protein supplements
-abuse of steroids
Anorexia Nervosa:
-self starving
-distorted perception of body shape and weight (Malnutrition affects brain functioning, judgment)
-females are 90-95% (much more common than males)

can be influenced by parents
often anorexists are perfecitonists
Respectful of authority: polite, controlled, rigid, unspontaneous
Bulemia and binge eating:
Bulemia:
-Binging and purging
-fear of gaining weight

Binge Eating:
-bulemia without the purging
(1/3 of obese people regularly engage in binge eating)

In both cases there are feelings of:
-being out of control
-disgust
-depression
-embarassment
-guilt
-distress b/c self-perceived gluttony
Bulemia Nervosa
much more common than anorexia:
-More men suffer from bulimia nervosa than from anorexia nervosa
-still most common in women
-sexual or physical abuse by family members or friends
Health Consequences of undernourishment due to anorexia nervosa
-protein-energy malnutriton
-Body tissues are depleted of needed fat and protein
-growth ceases in the young
-So much lean tissue is lost that BMR slows
-The brain loses significant amounts of tissue
-Nerves function abnormally
-Electrical activity of the brain becomes abnormal
-Insomnia is common
-Digestive functioning becomes sluggish (stomach emptying slows)
-The lining of the intestinal tract shrinks
-Digestive tract fails to absorb food
-Pancreatic production of digestive enzymes slows
-diarrhea
-anemia
-impaired immune system
-lost sex drive
MANY MORE
TREATMENT of eating disorders:
family support**

counseling and psychotherapy

Binge eating is more responsive to therapy than others
What is the most satiating nutrient?
Protein is the most satiating nutrient. Fat is also know for its satiating effect.

Protein and fat trigger the release of an intestinal hormone that slows stomach emptying and prolongs feelings of fullness

Satiety is also associated with:
-high fiber foods
-Water
-foods that have been puffed with air
Leptin
a satiating hormone...
1. suppresses appetite
2. produced by adipose tissue
3. travels to the brain
4. directly linked to appetite and body fatness

Roles:
1. signals the female reproductive system about fat reserves
2. may assist in sexual maturation
3. stimulates growth of new blood vessels in the cornea and elsewhere
4. constricts arteries
5. helps support immune function
Genetics and obesity:
*in RARE instances, the primary cause of obesity is genetics.

-children with at least one obese parent have a 40-70% chance of becoming obese

-lifestyle choices determine if genetic tendency is to be realized
3 keys to maintaining a healthy body weight:
1. maintain a proper diet
2. daily physical activity
3. behavior modification
can we override feelings of satiety and hunger?
yes we can eat even when we are full and choose not to eat even when our bodies demand it
Why do people tend to overeat at a buffet?
it has been proven that when a human (or animal) is prevented with variety then they will overconsume (eat even in the absence of hunger)
5 Other causes of overeating:
1. Loneliness
2. Craving
3. Availability
4. Price
5. Advertising
Smoking and weight loss:
1. nicotine blunts feelings of hunger
2. nonsmokers tend to weigh more than smokers
3. smoker who quit tend to gain weight
The Body's Initial Response to Fasting:
-liver glycogen stored are exhaused in < 1 day
-Protein is broken down and converted to glucose to feed the brain
The Body's Response to Continued Fasting:
-Continued breakdown of protein (muscle of the heart, skeletal muscle, liver, etc) will lead to death in ~ 10 days
-To prevent this, the body converts fat into ketone bodies, a fuel the nervous system can adapt to using
Ketosis:
-In ketosis, instead of breaking down fat to CO2 and H2O, the body takes partially broken-down fat fragments and combines them to form ketone bodies

-In addition, some amino acids, those that cannot be converted to glucose, are converted to ketone bodies

-After about 10 days of fasting, most of the nervous system’s energy needs are met by ketone bodies

-As a result of ketosis, a healthy person starting with average body fat content can live totally deprived of food for 6 - 8 weeks
How does fasting harm the body?
1. Ketosis upsets the acid-base balance of the blood, promoting excess mineral loss in the urine

2. In as little as 24 hours of fasting, the intestinal lining begins to lose its integrity

3. Food deprivation leads to overeating/ bingeing when food becomes available (this effect may last beyond the point of normal weight)

4. Fasting degrades the body’s lean tissues; tissues are deprived of nutrients needed for vital body components

5. The body also responds to fasting by decreasing its metabolic rate (therefore a moderate diet will lead to a greater weight loss than a severely restricted diet).
The Body's Response to a Low Carb diet
-low carb diets bring about responses similar to those seen when fasting
-As carbohydrate runs low the body breaks down fat and protein for energy and ketones form to feed the brain
-low-carb/high-protein diets bring about large initial weight losses (This large initial weight loss is primarily the water and glycogen losses that occur when carbohydrate is lacking, weight gain will be rapid once you return to a normal diet)...
-loss of appetite accompanies any low-calorie diet
Weight Gain: Energy-yielding nutrients contribute to excess body stores
Protein: excess amino acids lose their nitrogen and are used for energy or stored as fat

Fat: fatty acids can be broken down for energy or stored as body fat with great efficiency

Carbohydrate (other than fiber): excess sugars may be built up as glycogen and stored, used for energy, or converted to fat and stored.

*Take away message: all energy-yielding nutrients in excess are stored as body fat.
How does alcohol effect body fat?
Alcohol is either used for energy or stored as fat (like the energy-yielding nutrients).

Alcohol also slows down the body's use of fat as fuel by ~33%, causing more fat to be stored (primary as visceral fat)
Glycogen stores vs. body fat stores in terms of weight:
glycogen stores = ~3/4 of a pounds

fat stores = up to many many kilograms
What role does fitness play in disease prevention?
fitness appears to have a big impact on disease prevention...

normal weight unfit men have 2X the risk for chronic diseases as normal weight fit men

Overweight fit men have less risk than normal weight unfit men
Weight Gain Supplements:
most weight gain supplements are useless without physical activity

all they basically due is add calories (and few nutrients) to your diet

items such as instant breakfast powders or shakes will do the same thing for less money

of the weight gained in a day only about 15-30g of it is protein (therefore protein supplements will not speed up weight gain)