macronutrients Flashcards
name the three macronutrients
- carbohydrates
- proteins
- fats
T or F: amino acids are the only macronutrient that have some essential component
false. There are both essential fat and essential amino acid nutrients
define estimated average requirement
avg daily nutrient intake level estimated to meet the requirements of one half of the healthy individuals in a particular life stage and gender group
recommended daily allowance
avg daily nutrient intake level sufficient to meet the requirements of nearly all individuals in a particular life stage and gender group
RDA = EAR + 2 SD (EAR)
adequate intake
set if sufficient scientific evidence is not available to calculate an EAR or RDA
-based on estimates of nutrient intake by a group of apparently healthy people
tolerable upper intake level
highest avg daily nutrient intake level that is likely to pose no risk of adverse health effects to almost all individuals in the general population
estimated energy requirement
amount of food energy needed to balance energy expenditure in order to maintain body size, body composition, and a level of necessary and desirable physical activity consistent with a long-term good health
what makes up the total energy expenditure
- resting metabolic rate
- thermic effect of food
- physical activity
describe the trend of energy needed for growth
- 35% in first 3 months
- 5% at 12 months
- 3% in 2nd year
- 1-2% mid-adolescence
- negligible in late teens
state the kcal/g of food for: carbohydrates protein fat alcohol
carbohydrates: 4kcal/g
protein: 4kcal/g
fat: 9 kcal/g
alcohol: 7kcal/gram
acceptable macronutrient distribution range
a range of intakes for a particular macronutrient that is associated with reduced risk of chronic disease while providing adequate amounts of essential nutrients
what is a benefit of eating a polysaccharide like starch vs HFCS?
-bigger, broken down more slowly than simple sugars, longer lasting energy
Which of the following is correct:
A. refined carbohydrates are associated with a variety of health problems and including weight gain
B. refined carbohydrates raise insulin levels and promote obesity
C. refining often reduces or removes fiber, vitamins, minerals
D.complex carbohydrates provide longer lasting energy and contain indigestible dietary fiber which contributes to satiety
E. All the above
E. all the above
how is high fructose corn syrup (HFCS) made?
-corn syrups have undergone enzymatic processing to convert their glucose into fructose; mixed with pure corn syrup (100% glucose) to get sweetness right
how is HFCS ingested?
as a mixture of monosaccharides
have studies shown any significant difference between sucrose and HFCS meals in postprandial glucose or insulin responses?
NOOOOOO
glycemic index
measures the change in blood glucose that follows a consumption of a set amount of carbohydrate during a 2 hour period
are high GI foods digested rapidly or over a long period of time?
high GI foods are digested rapidly and absorbed resulting in marked increased in blood sugar levels
glycemic load
GI * grams of carbohydrate in a typical portion of food
T or F: a food’s glycemic index (GI) and their glycemic load (GL) are always similar
false, they can differ
what are some of the risks associated with consuming a relatively high GL diet long-term?
- increased risk of obesity
- type 2 diabetes
- cardiovascular diseases
acceptable macronutrient distribution range (AMDR)
-a range of intakes for a particular macronutrient that is associated with reduced risk of chronic disease while providing adequate amounts of essential nutrients
the AMDR for carbohydrates is ___ for adults
45-65%
**simple refined carbs like HFCS recommended to be avoided
a minimum of ___ grams a day of carbohydrates is recommended to avoid what problems?
- 130
- avoid ketosis, loss of lean body mass, ensure good glucose homeostasis
added sugars should not represent any more than __ of total energy intake?
10%
what is fiber?
nondigestible, nonstarch carbohydrates and lignin present intact in plants
what is soluble fiber?
- the edible part of plants that is resistant to digestion and absorption in the small intestine, but is completely or partiallly fermented by bacteria to short chain fatty acids in the large intestine
example: oatmeal, nuts, beans, vegetables, apples and prunes
what is insoluble fiber?
- passes through the digestive track largely unchanged
examples: seeds, skins of fruit, brown rice, wheat bran, whole wheat bread
which macronutrient is one of the most wide-spread deficiency in the American diet?
fiber, and its the least clearly understood
t or F: fiber provides a lot of energy
false
what are some of the benefits of fiber?
-absorbs 10-15 times its weight in water into lumen of intestine
-increases bowel motility and movements
soluble fiber delays gastric emptying and can result in satiety
-soluble fiber can lower LDL:C levels by increasing fecal bile acid excretion and interfering with bile acid reabsorption
AMDR for protein is
10-35%
in general plant proteins have ___ PDCAAS values than animal proteins?
-lower
what is PDCAAS
protein digestibility-corrected amino acid score
which source of proteins have more essential amino acids?
animals
is there any physiological advantage to consuming more protein than the RDA?
-no
excess protein is deaminated
resulting carbon skeletons are metabolized to provide energy of acetyl CoA for FA synthesis
excess protein consumption
is eliminated as urinary nitrogen
-often accompanied by increased urinary calcium thus increasing risk of kidney stones and osteoporosis
carbs are protein sparing which means…?
-adequate intake of carbs allows amino acids to be used for repair and maintenance of tissue protein rather than gluconeogenesis
Kwashiokor
- adequate caloric intake but INSUFFICIENT protein intake
- associated with severely decreased synthesis of visceral proteins
what are the symptoms of Kwashiokor?
-stunted growth, skin lesions, depigmented hair, anorexia, fatty liver, bilateral pitting edema, decreased serum albumin
considering Kwashiokor, describe the: weight for age weight for height if edema is present muscle and fat content
-weight for age: 60-80 %
-weight for height normal or low
edema is present
muscle and fat content is decreased
describe Marasmus
- chronic insufficiency for protein and calories
- occurs often in developing countries when breast milk is supplemented with cereals deficient in protein/calories
symptoms of marasmus
- NO edema present
- arrested growth
- extreme muscle wasting
- depletion of subcutaneous fat
- weakness
- anemia
are the fatty liver and skin and hair changes of kwashiokor observed in marasmus?
NOPE
what are the two essential fatty acids
-linoleic acid and a-linolenic acid
Can diet help lower blood cholesterol levels?
-10-20% change in plasma cholesterol with diet changes
the addition of what medication can lower plasma cholesterol by 30-60%
statins
dietary cholesterol has a relatively ___ influence on plasma cholesterol
-little
the amount and types of fatty acids in the diet has ___ association with plasma cholesterol levels and with CHD outcomes
-more dramatic
saturated fats
- associated with high levels of total plasma cholesterol and LDL and increased risk of CHD
sources: dairy, meat products, coconut oils and palm oils
what two saturated fats are most potent at increasing cholesterol?
-myristic and palmitic
does stearic acid have a major effect on blood cholesterol?
nope
monounsaturated fats (MUFAS)
-lower both total plasma cholesterol and LDL and maintain or increase HDL
plant based oils like olive oil
diets rich in olive oil show a low incidence of of __
CHD
polyunsaturated fats (PUFAS)
effects on cardiovascular disease are influenced by the location of the double bonds within the molecule
omega 6 fatty acids have what affect on plasma cholesterols?
-lowers total plasma cholesterol, LDL and HDL
physiological effects of omega 3 PUFAs
-suppress cardiac arrhythmias
-reduce plasma TAG
-decrease tendency for thrombosis
-lower BP
-substantially reduce risk of cardiovascular mortality
anti-inflammatory effects
-little effect on LDL or HDL
describe the behavior of trans fat
chemically classified as unsaturated fats, but behave and pack together like saturated fatty acids
trans fat effects on HDL and LDL
-raises LDL and lowers HDL
how are trans fats formed?
-hydrogentation of vegetable oils
Hydrogenation converts liquid vegetable oils into solid or semi-solid fats, such as those present in margarine
A side effect of incomplete hydrogenation having implications for human health is the isomerization of some of the remaining unsaturated carbon bonds, resulting in the trans isomers, which have been implicated in circulatory diseases including heart disease.[24] The conversion from cis to trans bonds is favored because the trans configuration has lower energy than the natural cis one. At equilibrium, the trans/cis isomer ratio is about 2:1. Many countries and regions have introduced mandatory labeling of trans fats on food products and appealed to the industry for voluntary reductions
