Nutrition Flashcards
classification of carbohydrates
- simple carbs (mono and disaccharides)
- complex carbs (amylose and amylopectin)
glycemic index (GI)
- measure of impact on CHO containing foods on blood glucose
- depends on rapidity of digestion and absorption
low GI
- 55 or less
- fruits, veggies, beans, minimally process grains, pasta, low fat dairy foods, nuts
moderate GI
- 56-69
- white and sweet potatoes, corn, white rice, couscous, cereal
high GI
- 70 or higher
- white bread, rice cakes, crackers, bagels, cakes, doughnuts, croissants
glycemic load (GL)
- incorp both quality and quantity of CHO
what foods have high GL
- CHO ric foods
- low fiber content
what foods have low GL
- whole grains, fruits, vegetables
- high fiber content
low GL
10 or less
medium GL
11-19
high GL
20 or more
to achieve a lower GL
- replace CHO with protein
- replace CHO with fat
- replace high HI CHO with low GI CHO
- combine all three
effect of high GL diets on coronary artery disease
- hypercoagulability
- hypercholesterolemia
- state of hyperglycemia
- insulin resistant state may be proinflammatory
- HTN
how does high GL cause hypercoagulability
- increase in serum platlet factors
- i.e. fibrinogen and vWF
how does high GL cause hypercholesterolemia
- accumulation of visceral fat
- reduction in lipoprotein lipase activity
- reduced clearance of TGs
why is insulin resistance pro-inflammatory?
- expression inflammatory mediator TNF alpha by adipose tissue associated with plasma insulin
how does high GL cause HTN
- oxidative stress -> reduced NO -> increased vascular and sympathetic tone
- angiotensinogen by adipose tissue -> activation of renin-angiotensin system
fructose
- monosaccharide
- found naturally in fruits and honey
- high fructose corn syrup is similar to table sugar (sucrose)
- excessive fructose consumption -> insulin resistance, obesity, HTN, dyslipidemia, DM
types of fiber
- soluble
- insoluble
soluble fiber
- helps lower glucose levels of blood cholesterol
- foods with soluble fiber include oatmeal, nuts, beans, lentils, apples, blueberries
insoluble fiber
- helps food move through digestive system
- promotes regularity and preventing constipation
- wheat, whole wheat bread, whole grain couscous, brown rice, legumes
building blocks of fat
- glycerol
- fatty acids
what type of fat is usually saturated
solid fat like butter or lard
what type of fat is unsaturated
- liquid fat like vegetable oil
- essential fatty acids cannot be synthesized by the body
- must be included in diet
what are the essential fatty acids
- omega 3
- omega 6
unsaturated fats
- “good fats”
- monosaturated vs. polyunsaturated
- poly is best
trans fat
- increases disease risk even in small quantities
- decreases HDL, increases LDL, pro-inflammatory
saturated fats
- best consumed in moderation
- i.e. red meat, butter, cheese
omega 6 metabolism
- converted to linoleic acid and then arachadonic acid
- AA is pro-inflammatory and enhances tumor growth
omega 3 metabolism
- converted to EPA and DHA
- EPA and DHA are anti-inflammatory and inhibit tumor growth
- due to low efficiency of conversion, recommended obtain EPA and DHA from other food sources
function of essential fatty acids
- affect cell membrane properties like fluidity, permeability
- DHA helps vision
- important for nervous system- brain has high levels of DHA and AA
obesity and cancer
- obesity associated with hyperinsulinemia, increased LDL, decreased HDL
- leads to increased IGF-1
- IGF-1 is mitogenic and antiapoptotic -> cancer
pathways that mediate trans fats with CVDD
- serum lipid concentratins (increased LDL and TG, decreased HDL)
- systemic inflammation
- endothelial cell function (reduced NO)
proteins
- need to be hydrolyzed by proteases and peptidases
- broken down in to AA, dipeptides, or tripeptides in small intestine
what do AA provide
- Nitrogen
- hydrocarbon skeletons
- sulfer
- essential precursors for synthesis of proteins, peptides, and other substances
- essential for health, growth, development, reproduction, lactation, and survival
which protein source is more biologically available
- animal proteins
metabolism
all chemical reactions in cells
calorie
- unit for expressing quantity of energy released from different foods
- 1 calorie= quantity of heat required to raise temp of 1 gram of water 1 degree C
- Calorie= 1000 calories
basam metabolic rate
- minimum level of energy required to exist
- normally 65-70 Calories/hr in average 70 kg male
CNS integrates inputs from
- long term energy stores i.e. leptin
- short term meal related signals
what whappens in the CNS in response to energy deprivation
- increased reward properties of food
- reduced response of satiety signals
leptin
- produced by adipose cells
- inhibits hunger
- plasma levels are proportionate to body fat stores
- act on neurons that regulate energy balance
what happens in response to acute and chronic energy deficiency in the brain
- increases feeding
- increases hepatic glucose production by increasing glucagon and corticosterone
- conserves energy by suppressing HPT axis
