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65 Cards in this Set
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calorie defn |
unit measure of energy 1kcal is the amount of energy (heat) needed to raise the temp of 1kg of water by 1C from 15-16C at one atm |
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calorie on food labels |
on food labels, kcal often used interchangeably w calorie but technically should be stated as Calorie or kcal technically, 1 kcal = 1000calories = 1Calorie small calorie: amount of energy needed to raise the temp of 1g of water by 1C from 15-16C at one atm internationally: food energy expressed as kilojoules (kj) 1 kcal = 4.184 kj |
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TEE |
Total Energy Expenditure = energy expended on maintaining basal metabolic rate, physical activity, thermal effect of feeding, and others (kcal/d needed to maintain current weight) TEE = BEE x Activity Factor/Stress Factor + TEF + EPOC -TEF and EPOC often not used in calculation |
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TEF |
thermic effect of food -contribute to TEE (small) |
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EPOC |
excess post-exercise oxygen consumption contribute to TEE (small) |
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BEE |
Basal Energy Expenditure = the matabolic activity necessary to sustain life (ie respiration, body temp, heart beat, etc) -roughly equals 25kcal/kg -makes up the majority of the total energy expenditure (TEE) |
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classes of nutrients |
Macronutrients -carbohydrates -lipids -proteins -water Micronutrients -vitamins -minerals |
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carbohydrates: roles |
-turned into glucose -> major source of energy for the body -supply glucose for CNS -role in metabolism, cell component structure |
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carbohydrates: storage forms |
-glycogen in muscle and liver -excess that cannot be stored as glycogen is stored as fat |
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carbohydrates: energy content |
4.1 calories/gram |
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carbohydrates: amount in diet |
adults: 45-65% of total daily calories should be from carbohydrates -higher end is for weight gain, endurance exercise |
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simple carbohydrates |
often referred to as "sugars" -mono and disaccharides: fructose, galactose, lactose, maltose, sucrose found in healthy foods such as: -fruits, milk, milk products, vegetables also in processed, refined foods: -candy, pop, syrups, table sugar aim for as natural a form as possible: -eg fruit instead of fruit juice, etc |
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complex carbohydrates |
often referred to as "starches" found in healthy foods such as: -legumes, starchy vegetables, whole grain breads and cereals also in processed, refined foods: aim for as natural a form as possible: -eg whole grain breads over white bread, etc |
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glycemic index (GI) |
a scale that ranks carbohydrate-rich foods by how much they raise blood glucose levels compared to a standard food (glucose or white bread) -50g useable carbohydrate GI of a specific food or meal is determined primarily by the nature of the carbohydrate consumed and by other dietary factors that affect nutrient digestibility or insulin secretion |
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low GI |
GI = 55 or less (choose most often) breads: ceral: -all bran, oat bran grains: -barley, pasta/noodles other: -sweet potato, yam, legumes (lentils, chickpeas, kidney beans, split peas) |
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medium GI |
GI = 56-69 (choose more often) breads: -whole wheat, rye, pita cereal: -puffed wheat, oatmeal grains: -basmati rice, brown rice other: -white potato, sweet corn, popcorn, stoned wheat thins, black bean soup |
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high GI |
GI = 70 or more (choose less often) breads: -white bread, kaiser roll, white bagel cereal: -bran flakes, corn flakes, rice krispies grains: -short-grain rice other: |
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GI in diabetes |
-suggest lower GI foods may decrease nondiabetic person's risk for T2DM, CVD, age-related eye disease in diabetes: better glycemic control, less hypoglycemic episodes, lower HbA1c Not included on canadian nutritional labels |
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glycemic load |
-refers to the global insulin demand induced by the diet -takes into account the quality (GI) and quantity (amount) of carbohydrate = the weighted average GI of individual foods multiplied by the % of dietary energy as carbohydrate eg. white potatoes have a high GI and high GL whereas carrots have high GI but low GL |
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sugar |
1tsp (5mL) = 4g = 16kcal the body handles naturally occurring sugars (eg fruit, milk) the same way it handles additive sugars (eg pop, candy) -additive sugar however lacks other nutrients |
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sugar: amount in diet |
Health Canada: _< 25% of total daily calories should come from added sugars WHO: _< 10% of total daily calories should come from added sugars diabetes: limit sucrose to < 10% of total daily calories |
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sugar substitute examples |
Aspartame (Equal, NutraSweet) -diet pop, diet foods, etc -containes phenylalanine Sucralose (Splenda) -diet pop, diet foods, etc Acesulfame K (Sunett) -diet pop: often combined w saccharin Saccharin (Hermesetas) -only available as tablets, sold in pharmacies -allowed in some food products (new) -animal studies: carcinogen -now condsidered to have no risk to humans Cyclamate (Sweet'N Low, Sugar Twin) -sold in packet, tablet, liquid, granulated form -cyclamate-containing foods, beverages cannot be sold in Canada |
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sugar subsitutes |
-less calories than sugar -may still have carbohydrates, fats less effect (than sugar) on blood sugars -"artificial sweeteners induce glucose tolerance by altering the gut microbiota" -blood sugar levels very high (reversible upon d/c of diet) |
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artificial sweeteners in pregnancy |
no rigorous studies considered safe: acesulfame aspartame sucralose |
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Stevia |
sugar substitute -fresh, dried, powdered leaves without health claims may be sold for personal culinary use -suggested max: 4mg/kg/d |
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sugar alcohols |
maltitol, mannitol, sorbitol, xylitol -up to 10g/d considered safe -no significant effect on blood sugars -sorbitol has 2.6kcal/g and is 60% as sweet as sucrose -mannitol has 1.6kcal/g and is 60% as sweet as sucrose fructose, sugar alcohols can cause irritable bowel |
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dietary fibre |
indigestible type of complex carbohydrate -thus supplies no calories |
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dietary fibers: recommendations |
children 1-3 y/o: 19g/d children 4-8 y/o: 25g/d > 8y/o: 25-35g/d (lower for females, higher for males) diabetes: 25-50g/d |
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soluble fiber |
dissolves in water, turns into gel -slows digestion |
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insoluble fiber |
absorbs water, does not become gel, but becomes bulkier -speeds food transit through stomach, intestines |
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sources of soluble fibre |
oats barley flax seeds seeds beans lentils peas some fruits (apples, oranges, pears, strawberries, blueberries) Psyllium some vegetables (celery, carrots) |
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sources of insoluble fibre |
whole wheat whole grains wheat bran corn bran seeds nuts brown rice fruits vegetables (cabbage, broccoli) root vegetable skins |
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foods that have 6 or greater grams of fibre/serving |
100% whole wheat bread (1 slice) = 6g Shredded Wheat (2 biscuits) = 6g Lentils (1 cup cooked) = 7g All Bran cereal (1/2 cup) = 10g |
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easy ways to increase fibre intake |
-trade white for brown -choose fruits or vegetables over juice -avoid peeling fruits and vegetables, where possible -eat oatmeal or 100% bran cereal for breakfast -add barley, lentils, legumes to soups or salads |
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energy content of lipids |
9 kcal/g |
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benefits of fats |
-source of energy -protects internal organs -aids in the absorption of fat-soluble vitamins A, D, E, K -temperature regulation |
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lipid recommendation |
adults: 20-35% of daily calories
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unsaturated fat |
-should make up the majority of daily fat intake -lower LDL cholesterol |
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monunsaturated fat |
most of total daily fat should come from this -typically liquid at room temp; turns solid when chilled -also higher in vitamin E |
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sources of monounsaturated fat |
-vegetable oils (olive, canola, peanut, sunflower, sesame) -avocados -natural peanut butter -nuts -seeds |
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polyunsaturated fats |
aim for 3-10% of total daily fat -typically liquid at room temp and when chilled -lower cholesterol (note: no evidence to support non-dietary supplement use to prevent CVD events in pts w CV disease) 2 types: -omega-3 -omega-6 |
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omega-3 FAs |
3 types: -alpha-linolenic acid (ALA) -body partially converts to DHA, EPA -docosahexaenoic acid (DHA) -eicosapentaenoic acid (EPA) overal, omega-3 PUFA supplementation was not associated w lower risk of all-cause mortality, or CV events |
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ALA sources |
body partially converts to DHA, EPA -walnuts -omega-3 eggs -flaxseed -soy products -canola oil |
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DHA and EPA sources |
salmon anchovies herring sardines pacific oysters trout mackerel canada food guide suggests 2 servings of fatty fish weekly |
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omega-6 FA |
Linoleic acid |
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linoleic acid sources |
soybean oil corn oil safflower oil some nuts, seeds |
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optimal ratio of omega-3:omega-6 |
-in dispute -the general western popn consumes a higher proportion of omega-6 in processed foods (eg soybean oil) |
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saturated fat |
-tend to be more solid at room temp -for decades, blamed for increases in total and LDL cholesterol and TG -systematic review disputes this |
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saturated fat recommendation |
current guidelines: aim for _< 7% of total daily calories |
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sources of saturated fat |
animal meat dairy coconut avocado |
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trans-fats |
aka partially-hydrogenated oils) -increase total and LDL cholesterol -decrease HDL -associated w increased risk of developing T2DM |
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trans-fat recommendations |
limit intake to < 1% of total daily calories -this is probably achieved form naturally-occurring trans-fats in milk, meats |
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trans-fats sources |
-many commercially baked pastries, cookies, crackers -foods deep-fried in partially-hydrogenated oils -stick margarines -shortenings |
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protein: role |
provide building blocks for cell and tissue growth and repair -muscles, organs, skin, nails, etc -used to make enzymes, hormones may be broken down to provide energy |
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proteins: storage |
may be converted to fat |
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protein: energy content |
4.1 kcal/g |
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protein recommendation |
10-35% of total daily calories pregnancy: 0.88 g/kg/d lactation: 1.05 g/kg/d general range for adult: 0.88-1g/kg for weight gain: up to 2g/kg max higher intakes (1.5-2g/kg) may be needed to preserve muscle if lots of aerobic training |
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essential amino acids |
-cannot be made by humans -9: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine |
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complete vs incomplete proteins |
animal proteins are complete (contain all essential aa) plant proteins are incomplete, except quinoa (low in one or more essential aa) -this can be overcome by mixing different plant proteins throughout the day eg combinations: -legumes w grains -legumes w nuts or seeds |
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caffeine recommendations |
max: adults: 400mg/d pregnancy: 300mg/d |
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alcohol: standard drink measures |
1 standard drink = 13.5g of alcohol = 5 oz wine = 142mL = 1.5 oz spirits = 43 mL = 12 oz beer = 341mL coolers and higher alcohol beers have more alcohol than one standard drink |
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problems with the Canada Food Guide |
-will meet nutritional needs but not necessarily calorie needs -vitamin D needs may not be met -calorie needs and food choices vary among individuals -if more calories are needed, emphasize more food from the food groups to maintain macronutrient profile |
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Eating Frequency (EF) |
does a high eating frequency assist w weight management: 2 opposing beliefs: 1. weight management -snack foods are higher in carbohydrates; thus those who snack regularly may manage weight successfully (b/c replacing fat w carbs) -higher EF leads to less hunger -limiting to 3 large meals -> lethargy, less physically active 2. weight gain -higher EF -> weight gain (more eating and excess calories) systematic review: no association between EF and weight status |
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importance of breakfast |
in children:
-conflicting results wrt cognitive, performance, memory, impulsivity, reasoning, attention, concentration -associations w positive academic test scores, academic grades, school attendance body weight -conflicting results of adults, children -generally most observational trials associate breakfast (in children) w a decreased risk of being overweight or obese breakfast consumers more likely to have better overall diet quality, micronutrient and macronutrient and fiber intakes that more often align w current dietary recommendations |
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is it better to eat organic food? |
-no evidence of any significant nutritional benefit over regular food -no difference in nutrient profile -unclear if eating organic lowers pesticide exposure -EWG credible? some studies suggest pesticides increase risk of certain cancers -no definite link -people exposed (eg work in agriculture) may have increased risk -fruits/veg considered to have very small amount of pesticides -no evidence that this increases human risk of cancer -there is evidence that eating organic does not decrease the risk of cancer |
