Unit 6 - Macronutrients, Energy Intake, and Expenditure

Question 1

arguments FOR “food pyramid” that reduces total fat consumption

Answer 1

1. high fat diets produce postprandial lipemia
2. people who eat plants foods lose weight more easily
3. more energy is expended metabolizing CHO than fat
4. high fat diets have increased cancer risk
5. fruits and veggies have fiber, antioxidants, and w-3s
6. anything else is too confusing

Question 2

arguments for distinguishing between fats, and replacing sat fat with MUFA and PUFA

Answer 2

1. replacing with CHO lowers both HDL and LDL (olive oil lowers LDL only)
2. no good evidence for better weight reduction
3. cancer-fat correlation only for animal fat
4. more fruits/veggies should be eaten instead of sugar/starches (poor compliance)
5. walnuts, canola/fish oils are better sources of w-3 than fruits/veggies
6. CHO also produce postprandial lipemia
   - excess glucose converted to FA and exported from liver as VLDL
7. people are educated to understand difference between saturated VS unsaturated

Question 3

have efforts to improve nation’s health with USDA food pyramid been successful?

Answer 3

no

Question 4

REE formula for males VS females

Answer 4

male: 900 + 10(kg)
female: 700 + 7(kg)

Question 5

activity coefficients for adjusted energy expenditure

Answer 5

sedentary: 1.2-1.3
moderately active: 1.4
very active: 1.8

Question 6

WHO classification for BMI

Answer 6

40 = grade 3 overweight (morbidly obese

Question 7

what are advantages and disadvantages for BMI measurement?

Answer 7

pro: easy to measure and good reproducibility; strong correlation with densitometric fat mass measurements; demonstrated usefulness in assessing relative risk of various disorders
con: failure to distinguish fat from lean mass; failure to distinguish upper body (truncal) fat from lower body fat

Question 8

how does marasmus (severe calorie deficiency) compare to kwashiorkor (edematous PRO malnutrition) symptom-wise?

Answer 8

marasmus: no fat; loss of muscle (esp. shoulders and butt); thin, dry, easily wrinkled skin; sparse, thin, dry hair; apathy/anxiety; pinched face; distended belly from weak muscles (but gas, not edema)
kwashiorkor: pale skin with burn-like lesions; cyanotic extremities; brittle, pluckable hair; hepatomegaly from fatty deposits; irritibility; edema (esp. hands/feet); hypotension/glycemia

Question 9

what percentage of adipose tissue is fat and water? what does this mean calorie-wise if someone loses 1 kg of fat

Answer 9

85% fat, 15% water

since 1 kg of adipose is 850 g of fat, and there are 9 kcal/g for fat, that means a 7650 loss of kcal

Question 10

how much of weight loss should be assumed to be adipose tissue?

Answer 10

all of it

Question 11

what is the problem with fructose?

Answer 11

metabolized primarily in liver, and differently than glucose

• if liver gets too much fructose, it turns into TG deposits in liver itself
• steatosis causes metabolic derangements, including insulin resistance

Question 12

what does the glycemic index compare?

Answer 12

differences in rate of digestion
-higher GI, greater insulin spike (postprandial insulinemia harmful in long run, “wearing out” pancreas and predisposing DM2)

Question 13

what is the percentage of fat:CHO:PRO for the American Diabetes Association and American Cancer Society?

Answer 13

20:60:20

Question 14

what disease is trans fat consumption strongly associated with?

Answer 14

coronary artery disease

Question 15

what disease is saturated fat consumption strongly associated with?

Answer 15

atherogenic; increased risk of coronary heart disease

-but not all saturated fats are the same

Question 16

what do w-3 PUFAs do for our health? how does this relate to fish consumption?

Answer 16

reduce risk of CHD, but unclear mechanism
-beneficial effects of eating fish don’t correlate with w-3 content, and must reflect additional factors (fish PRO, the eaters themselves, etc.)

Question 17

what are eicosanoids made from?

Answer 17

w-3, not w-6 arachidonic acids

Question 18

what is the overall goal of Atkins diet to lose weight?

Answer 18

induce mild ketosis (monitored with urine test strips) by depleting glycogen stores

• early weight loss due to water loss, and there’s less retention of body water
• but research shoes inefficiency of KB metabolism only accounts for a small percentage of claimed weight loss; other mechanism is unclear

Question 19

what does the Atkins diet do to blood lipids?

Answer 19

LDL stays the same

HDL increases

TG decreases

Question 20

what must a weight loss diet do? what is the “closest type of diet” to do this?

Answer 20

reduce risk of developing DM2 and atherosclerosis, and not significantly increase risk of other diseases
-low carb, low trans, low sat, high unsat, high PRO