Macronutrients Flashcards
What are the 3 major macros?
- Carbs
- Lipids
- Proteins
How do we measure macros?
Gram quantities
What is the purpose of macros?
Provide us with energy (calories)
What does the AMDR tell us?
Acceptable Macronutrient Distribution Range
Percentage of energy intake that should come from each macro for optimal body fxn
What are the AMDRS for carbs, lipids, and proteins?
Carbs - 45-65% cal
Lipids - 20-35% cal
Proteins - 10-35% cal
How do we derive our protein RDA?
0.8 g/kg body weight
T/F: Men require more fiber than women.
True - men need 38g, women need 25g
What manufactures carbohydrates?
Plants
What are the 2 major categories of carbs/what are contained in each category?
Simple:
- Monosaccharides
- Disaccharides/Oligosaccharides
Complex:
3. Polysaccharides
What is C1(H2O)1?
Hydrated carbon aka 1 carbohydrate
How many Cal/g do we get per carbohydrate?
4 Cal/g
What are the 3 monosaccharides?
Glucose
Fructose
Galactose
What are the 3 disaccharides?
Sucrose
Lactose
Maltose
What are the 3 polysaccharides?
Starch
Glycogen
Fiber
How many carbons are in a monosaccharide?
3-7
MC are 6C = hexose
What is the sweetest of all monosaccharides?
Fructose
What is the epimer/isomer of glucose?
Galactose
What is galactosemia?
Inability to metabolize galactose
Which of the 3 monosaccharides is required by the brain?
Glucose
Which carbohydrates are digested by brushborder enzymes?
Disaccharides (bound by glycosidic bonds)
Which disaccharide is Glucose (alpha1-beta2) fructose?
Sucrose
In older men and women, does our fiber RDA increase or decrease?
Decrease
men - 30g
women - 21g
What is the difference in taste between simple and complex carbohydrates?
Simple = sweet Complex = not sweet
Which carbohydrate is a ‘non-reducing’ sugar?
Sucrose (derived from glucose + fructose)
What is an invert sugar?
Free glucose and fructose in a 1:1 ratio
Honey is a natural example
What is the most common form of carbohydrate malabsorption?
Lack of lactase (25% of adults world wide)
Galactose beta(1-4)
**Beta means indigestible/hard to break, alpha means digestible
What is the product of starch degradation?
Maltose (derived from glucose + glucose)
Glucose alpha(1-4)
What is the current recommendation for added sugars in food?
<10% of total energy consumed
How long are oligosaccharides?
3-10 sugars
How can we describe oligosaccharides?
Difficult to digest - act as fibers
Water soluble
Often sweet
How many sugars comprise polysaccharides?
10 or more
Which polysaccharide comes from plants? Which comes from animals? Which comes from plants but is indigestible?
Plants - Starch
Animals - Glycogen
Indigestible - Fiber
What is a branched starch? Linear starch?
Branched - amylopectin
Linear - amylose
Which type of starch is corn and rice based and contains a high percentage of amylopectin?
Waxy starch - seen in frozen foods
What is a resistant starch?
Recrystallizes after cooking to resist digestion (usually fermented)
Which polysaccharide is 100% glucose?
Starch
Which starch is most resistant?
RS3 - retrograded from cooling gelatinized starch
What is the difference in appearance between amylose, amylopectin and glycogen?
Amylose is linear (plant starch)
Amylopectin has long, infrequent branches (plant starch)
Glycogen is highly branched (remember: glycogen is an animal starch)
Note: Amylopectin and Glycogen have the same bond
alpha(1-4)>alpha(1-6)
Where does digestion of starch begin? What enzyme is required?
Begins in the mouth with alpha-amylase (randomly digests alpha(1-4) bonds
What is the yield of alpha-amylase
Dextrins (medium length glucose strands from amylose)
Limit Dextrins (medium length containing alpha(1-6) from amylopectin)
Which brushborder enzymes are required to digest dextrins/limit dextrins?
Maltase & Isomaltase
T/F: Glycogen is found in plants and animals.
False! Animals only!
What is the storage form of carbs in plants? In animals?
Plants - starch
Animals - glycogen
What regulates blood glucose?
Liver
100g = 400kcal when full
How long can we store glycogen in the liver before it is depleted (fast state)
15 hours
How much glycogen is used in the liver after 1 hour of aerobic activity?
50%
How much glycogen is released from muscle?
None - once phosphorylated it remains in the muscle
How much glycogen is stored in the muscle?
350g = 1400 kcal in sedentary individual
May double in trained muscle
What is a functional fiber?
Fiber that has been extracted from plants and added to foods/supplements
What are the two types of dietary fiber?
Insoluble and soluble
What are the two types of soluble fiber?
Viscous fiber (good binder/gel-forming)
Fermentable fiber (metabolized by colonic bacteria)
Which fiber swells in water?
Soluble fibers
What is an example of a lignin?
Woody stalks of broccoli or asparagus
Which types of fiber are both viscous and fermentable?
Pectin
Beta-glucans
**Gums can be both, but guar gum specifically is fermentable only*
What fibers are only viscous?
Psyllium
Konjac Glucomannan
What fibers are only fermentable?
Inulin
Wheat Dextrin
Guar Gum
What food can contain up to 14g fiber/serving?
Bran cereals
What are good sources of fiber?
Beans, Veggies
What are okay sources of fiber?
Fruit, Nuts, Seeds, Breads
Which type of fiber increases fecal volume and decreases GI holding time?
Insoluble fiber (cellulose, lignin, some pectins)
Which fiber can decrease absorption of cholesterol and minerals?
Soluble fiber
What are the bi-products of fermentable fiber?
Gas
Short chain FA (energy)
Which two mineral binders are present in fiber rich foods?
Phytate
Oxalate
What can help decrease the risk of type II diabetes?
Increased consumption of soluble fiber (limits glucose absorption)
How many grams of fiber intake/day are required to decrease risk of colorectal cancer?
10g of dietary fiber (reduces risk by 9%)
What is the adult RDA for carbs?
130g/day
T/F: The Average American adult consumes 12-18g of fiber/day, surpassing their AI levels.
While the American average is true, this statement is FALSE because the AI for adults 18-50 is 38 (men) and 25 (women), respectively (levels decrease after 50)
What is a normal fasting blood glucose level?
70-99 mg/dL
What peptide hormones regulate blood glucose levels?
Insulin & Glucagon
What levels of fasting blood sugar are considered pre-diabetic?
100-125 mg/dL
How does eating carbs effect blood glucose levels in a healthy patient?
- Eating carbs raises blood glucose
- Pancreas releases insulin from beta cells
- Insulin binds to insulin receptors
- IRS-1 is recruited to the receptor
- IRS-1 begins a signal transduction cascade to tell the golgi complex to make GLUT4
- GLUT4 is translocated from golgi complex to plasma membrane
- Glucose is able to enter muscle or adipocytes for storage or use
- Blood glucose decreases to normal
How does eating carbs effect blood glucose levels in a insulin-resistant patient?
- Insulin binds to insulin receptors
- IRS-1 is recruited to the receptor
- Excess inflammation (C-reactive protein/CRP) abnormally phosphorylates IRS-1 (on 2 serine residues), causing it to not signal properly
How does insulin use glucose in the cell (from low to high levels of glucose)?
ATP
Store glucose to glycogen in muscles & liver
Turn into adipose tissue
How does a healthy patient respond to low blood glucose levels?
- Blood glucose drops between meals
- Pancreas releases glucagon from Alpha cells
- Glycogen is broken down into glucose
- Glucocorticoids inhibit glucose uptake
- GNG occurs
- Blood glucose increases to normal levels
How does low blood glucose affect adipose?
Fatty acids and Glycerol (Triglycerides) enter the blood stream
How does low blood glucose affect muscle?
Lactate (from pyruvate/glycogen) and Alanine (protein) enter the blood stream
What are the 2 main mechanisms of making ROS?
Respiratory burst (MC)
ETS
What’s the cofactor for GPx?
Selenium
What’s the cofactor for CAT?
Iron
What is responsible for turning H2O2 into H2O?
GPx
CAT
What is Glutathione (GSH)? Where is it found? Where is it primarily used?
Antioxidant tripeptide synthesized in the liver
Found in plasma and cytoplasm and mitochondria of cells
Primarily used in Liver
Where is catalase found?
WBCs and peroxisomes of cell
What are examples of fat-soluble H donators?
Coenzyme Q10
Carotenoids (proformed vit A)
vitamin E (found in membranes)
What are examples of water-soluble H donators?
Vitamin C
Glutathione
Polyphenols
BHA/BHT
High concentrations in fruits/veggies/whole grains/legumes
What helps to regenerate vitamin E?
*Vit C
Beta carotene
CoQ10
Glutathione
**Vit E acts as potent anti-oxidant. If you over-supplement with Vit E it can act as a pro-oxidant. We want to get AOX at smaller/natural concentrations
What are the benefits of Alpha-Lipoic acid?
Required for ATP synthesis
Aids in nerve regeneration
Anti-inflammatory
Anti-oxidant
Body produces it; both fat/water soluble
What are the 6 major nutrients of concern in a vegetarian diet?
Vit D (non-lacto) Calcium (non-lacto) Zinc (non-pesco, non-semi) B12 (vegan) Iron (RDA is 1.8 times higher for ALL vegetarians) Omega-3s (non-pesco, non-semi)
What is the average caloric requirement for a vegan?
2383 cal (vs 2985 for omnivore)
vegans require the least amount of calories compared to other vegetarians
Where do we synthesize plasma proteins?
Liver!
What is the major glucogenic AA released from muscle?
Alanine
What are the causes & symptoms of Hyperglycemia?
Caused by persistently high blood glucose levels
Diabetic levels = >126mg/dL
Symptoms: frequent urination, dehydration, thirst
**Kidney can’t reabsorb all the glucose in these patients, therefore it winds up in the urine, pulling lots of water with it
Which type of diabetes is a GLUT 4 issue?
Type II