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120 Cards in this Set
- Front
- Back
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what are the 3 macronutrients? why are they called this? |
proteins fats carbs
needed in large quantities to provide fuel and raw materials for structural/functional integrity |
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chemistry of carbohydrates basic unit? source of most carbs? |
C,H,O monosaccharide (CH2O)n linked together to make sugar chains
except for lactose and glycogen, plant-derived |
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hames of monosaccharides (3) |
glucose fructose galactose |
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glucose! aka? created in body from? (2) how absorbed into circulation? once absorbed, used to (3)? |
dextrose created by: -digestion of food/direct absorption -gluconeogenesis (conversion of lactate, pyruvate, amino acids in the liver)
absorbed into circulation via small intestine
-remains as glucose to use as energy against hypoglycemia -convert to glycogen and stored in liver/muscles -converted to fat and stored |
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fructose aka? comes from? used how? |
fruit sugar! sweetest fruits/honey converted to glucose by liver then used |
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galactose it is a _____ sugar? how found in nature? how animals with mammary glands use it? how body uses it? |
milk sugar not found unbound in nature fuse with glucose to form lactose convert to glucose in liver then used |
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oligosaccharides definition? examples? |
2-10 monosaccharides chemically bond to form short chain! sucrose=glucose+fructose (*obesity*) lactose=glucose+galactose (milk sugar; calorie-booster) maltose=glucose+glucose (beer; cereal; germinating seeds) |
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polysaccharides definition? examples? |
3-1000's monosaccharides joint by dehydration synthesis animal--glycogen plants--starch, fiber |
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plant sources of carbs? (2) |
starch-plant storage of carbs! fiber-structural polysaccharide! |
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types of starch? |
amylose-long, straight glucose chain; breaks down slowly amylopectin-highly branched glucose chain; breaks down fast |
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fiber! what is it? digestable? increased intake=? how much do we want? types? |
structural polysaccharide
not digestible in human body
lined to LOWER BODY FAT MASS (facilitates gut motility and removal of bile acid salts in the intestines--lower LDL)
20-40 grams per 2000 calorie diet
water soluble and insoluble |
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animal storage of carbs? stored where? enzyme? structure? how much do we have? |
glycogen
skeletal muscle and liver
glycogen synthase!
very compact structure so lots of molecules in small space
500 g carbs in the form of glycogen (2000 kcal) 400 g in skeletal muscles; 100 g in liver |
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how is glucose and hormonal control related? |
insulin produced by pancreatic beta cells when plasma glucose is too high and causes cells to take in glucose until reestabilsh resting levels
glucagon produced by pancreatic alpha cells when plasma glucose it too low and causes gluconeogenesis (create glucose) or glucogenolysis (liberate glucose) |
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normal blood glucose level? |
70-110 mg/dL |
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what causes spikes in blood glucose? what minimizes spikes? |
simple sugars and fast digesting starchs (high-glycemic index carbs)
fiber and slow digesting carbs (low-glycemic index carbs) |
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what do spikes in blood glucose cause? further more that causes? |
release of insulin and over time insulin resistance!!
hyperinsulinemia elevates plasma triglyceride levels and facilitates fat synthesis and storage |
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what happens in type 2 DM? |
insulin production is outpaced by blood glucose (sugar always high)
resistance=greater body fat gain (especially with high-glycemic index carbs)
extra insulin (decreased effectiveness) makes body oxidize glucose instead of fatty acids so get VLDL production and fatty acid storage in adipocytes |
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how does exercise help diabetes? |
improve insulin sensitivity regardless of body fat levels! |
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recommended intake of carbs? |
sedentary--300 g or 40-50% of total calories
active--400-600 g or 60% of total calories
athlete--70% total calories (8-10 per kg body weight) |
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what roles do carbs play in the body? (4) |
1) energy source --primary energy source for work; during high intensity exercise
2) CNS and RBC fuel
3) protein sparing --if no glycogen, body converts plasma proteins to glucose (catabolic) via deamination
4) metabolic primer --prime fat oxidation pump --when glucose is low, get build up of ketones and possibly ketosis (metabolic acidosis) due to imbalance of fat mobilization to breakdown |
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what happens when glycogen stores are maxed out? |
convert circulating glucose/carb to fats and store it |
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how are carbs used during exercise?
intense exercise? |
muscle glycogen provides carbs in early and increasing intensity increases then liver glycogen mobilized as intensity increases
muscle glycogen accounts for 30% circulating glucose but with depletion and intensity, get glucogenolysis from liver....after 1 hr, 55% liver glycogen gone and after 2 hrs liver is empty |
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why are carbs preferred during high intensity aerobic exercise? |
supply of ATP to working cells is rapid compared to protein and fat metabolism |
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carbs during moderate/prolonged exercise?
what happens as a result of this? |
muscle and liver glycogen deplete so fat catabolism (some protein catabolism) provide energy
after 2 hrs of exercise, body can only get 50% of initial intensity since ATP from fat is slower; power (work/time) decreases to 50% of initial levels |
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what is fatigue? |
exercise compromises liver and muscle glycogen supplies
also could be due to metabolic by-products of fats and protein oxidation for ATP |
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chemical structure of lipids?
where is most stored? |
CHO like carbs but different arrangement H:O is >2:1 found in carbs (can be 18:1)
90% in subcutaneous fat stores |
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types of lipids? |
simple compound derived |
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types of simple lipids? |
triglycerides saturated fatty acids unsaturated fatty acids |
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simple lipids aka_____; composition? characteristics? (4) |
triglycerides glycerol+3 fatty acids
-neutral fats (no electrical charge at bodys pH) -insoluble -stored in adipocytes -longer fatty acid chain=less soluble
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saturated fatty acids chemical composition?
dietary sources? (3) *key characteristic* |
one single covalent bond between C which are saturated with hydrogens
animal fats plant oils hydrogenated shortenings
*solid at room temperature* |
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unsaturated fatty acids chemical composition? ypes and their chemical composition? (2)
dietary sources? |
>1 C molecule in fatty acid chain has a double/triple bond; C is unsaturated with H
monounsaturated--only 1 unsaturated H polyunsaturated-->1 unsaturated H
plant based...NO ANIMAL FATS |
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chemical composition of compound lipids? types of compound lipids? |
triglyceride+chemicals other than CHO
phosopholipids glycolipids lipoproteins (chylomicrons, LDL, HDL, VLDL) |
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functions of phospholipids? (4) |
-control movement across cell membrane -maintain cell structural integrity -role in blood clotting -structural integrity to insulating sheath of nerves |
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liproproteins chemical composition? shape? allows? |
protein+ phospholipid/triglyceride
spherical shape allow lipids to bind to proteins for transport |
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chylomicrons formed by? metabolized in? assist? |
emulsification of lipid as leave small intestine; liver metabolizes and stores in adipose; transport fat soluble vitamins ADEK |
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high density lipoprotein %'s? function? |
50-20-20 protein, lipid, cholesterol
scavenge LDL in blood and arterial wall (room to pick up extra fats) |
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low density lipoprotein very low density lipoprotein chemical composition? funciton? |
up to 95% lipid!!!!
carry cholesterol and form arterial plaques |
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what LDL:HDL ratio do you want? total cholesterol in blood desired? |
3:1 200 mg/dL so LDL 100: HDL 35 |
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alot of HDO is_______ |
cardioprotective! |
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derived lipids chemical composition? example? |
combo of simple+compound lipids
cholesterol! |
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cholesterol found where? chemical composition? comes from? (2) special function? |
animal tissue
NO FATTY ACIDS!
exogenous(diet) or endogenous (liver; 2 g/day)
base for most hormones (notes: can also use for phospholippids, cell repair/growth) |
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good/bad to have very low cholesterol? |
bad!! affects myelination of nerve cells and therefore brain function |
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recommended dietary lipid intake? |
same for active and sedentary!
no > 20% calories from lipids no more than 200 mg cholesterol per 2000 kcal (2 eggs a day rule) |
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what will a decrease in lipid intake do? |
decrease endogenous cholesterol production! so helps reduce risk factors for coronary artery disease |
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roles of lipid in the body? (4) |
1) energy source and reserve --large energy per weight --transports and stores easily
2) protection of organs from impact
3) thermal insulation
4) vitamin carrier and hunger suppressor |
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fat dynamics in: light-moderate exercise moderate high intensity |
some carb energy, mostly fatty acids
equal carb and fat energy
carbs, primarily muscle glycogen |
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protein! chemical composition? building blocks? how they combine? # monomers? |
CHO and an amine group (called amino acid-monomer) link amino acids together via peptide bonds into polypeptides (aka proteins) 20 AA create 80000 proteins! |
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essential amino acids? #? |
body cant synthesize; must get from diet
8 |
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nonessential amino acids? #? |
can be synthesized by the body from other chemicals
roughly 9 |
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complete vs. incomplete proteins? origin? |
complete-dietary proteins with all 8 essential aa's (animal)
incomplete-lack 1 or more essential aa (plant)
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what is the impact of an incomplete protein on diet? |
must balance missing essential proteins
effects the protein usability and biological value-quality of a foods protein rated on a scale of 100 (eggs are 100) |
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where can protein be found? |
animal and plant tissue! |
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recommended protein diet intake? |
0.83 kg per kg of body mass |
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what can increase protein requirements?
is excess harmful? how much is too much? |
stress, disease, exercise, injury
yes! strains the liver and kidney function; >1 g of protein per lb body weight is too much |
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where is protein found in the body? (3) % of body mass which is protein? role o do we store protein? role? (3) |
blood plasma, visceral tissue, all muscle types 12-15%
no! -incorporated into body structure -synthesize metabolically active compounds (enzymes) -deaminated and converted to glycogen/fat for storage
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what typically happens in protein metabolism? outlier effect? |
usually used for anabolic processes!
CAN (5%) can be catabolized for energy |
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what happens when proteins are catabolized? *steps!* |
-protein split into its amino acids -deamination (lose amine group) in liver to form urea --deaminated aa is converted to another aa (transamination), fatty acid, carb, or used for energy -urea disolved in water in kidney and leaves body as urine
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so why is excess protein bad for body? |
excessive strain on kidneys |
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SO what happens to aa after deamination? (3) |
1) gluconeogenesis-converted to glucose and used as energy 2) energy source directly 3) fat synthesis |
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where does nitrogen come from? (FUSF)
what can your balance be? + nitrogen balance means? - nitrogen balance means? |
food, urine, sweat, feces
+, -, or 0
overall body growth (pregnancy, childhood)
catabolic process (starving, over training) |
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when is protein used in exercise?
when does protein synthesis in muscles occur? |
depends on the availability of other prefered substrates (carbs/fats)
AFTER intense exercise; while RECOVERING |
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daily recommendation for intensely training athletes? |
1.2-1.8 g of protein/kg bodyweight per day |
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alanine-glucose cycle? |
represents one way proteins may contribute to energy (gluconeogenesis)
alanine is an aa derived from pyruvate. released from active muscles direct proportion to exercise intensity. travels to liver and is deaminated; converted to glucose and transported back to the working cells via circulation |
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how does training effect this system? what does this system provide as an end result? |
training increases the efficiency and output of this system
10-15% of total exercise energy requirement |
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what are micronutrients (2)? |
vitamins and minerals |
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vitamins types? how made? |
fat soluble (ADEK) water soluble (BC)
body CANNOT MANUFACTURE these except for D |
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fat soluble vitamins storage? roles? |
stored upon ingestion so dont need daily
-bone synthesis (help Ca absorption -clotting cascade -anti-oxidant mechanism -epithelial tissue maintenance |
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water soluble vitamins stored? when too low? main function? |
cannot be stored and must be ingested daily; of <50% daily allowance, get deficiencies in around 4 weeks
co-enzymes! combine with a protein and form an active enzyme to accelerate a chemical rx |
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free radicals
what will they do? (2) |
unstable, chemically reactive substances that want to oxidize (take e-) susceptible substances
1) react with e- rich DNA and cell membranes 2) create more free radicals as they react with DNA and cell membranes |
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oxidative stress
what does it contribute too? |
attack on cells and DNA by free radials
rapid aging, atherosclerosis, neoplasm |
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how do vitamins help with free radicals? |
anti-oxidant function! shield body from the potential to harm DNA and cell membranes |
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what is the recommended diet intake of vitamins? |
if good diet, dont need to supplement
excess vitamins does not good and may harm you via vitamin toxicity |
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minerals functions? (4) |
1) provide structure in forming bones/teeth 2) maintain normal function 3) regulate metabolism by being constituents [elements] of enzymes and hormones that modulate cell activity |
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types of minerals? |
7 major 14 trace |
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what 4 things does mineral absorption depend on? |
A) type of food consumed B) vitamin-mineral interaction C) mineral-mineral interaction D) mineral-fiber interaction |
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examples of the interactions |
B) vitamin C helps get iron into body C) calcium interrupted by oxalic acid D) fiber binds calcium, magnesium and stop their absorption |
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calcium functions? (3)
rate of absorption? |
-create mineral skeleton of teeth & bones with phosphorus -nerve signal conduction -muscular contraction (especially cardiac muscle)
poor overall absorption so need lots daily |
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what are some effects of calcium deficit? |
ostopenia-bone density decrease 0-2.5 SD for normal gender/age
osteoporosis-" " > 2.5 SD |
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wolfs laws tie into calcium? |
bone density is influenced by it! calcium needed to remodel bones in response to increased stresses so need it to combat pathological decrease in bone density |
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is it recommended for supplement? |
yes, to postmenarchal females |
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what is the female triad? 3 signs? |
pre-menopausal females exercise intensely while emphasizing total weight loss (no regard to the type of mass lost)
-secondary amenorrhea -osteoporosis -energy drain/fatigue |
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what is the treatment for female triad? (4) |
-increase Ca to 1500 mg daily -reduce training intensity & volume 10-20% -increase caloric intake gradually -body weight increase 2-3% |
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what are some other important minerals? |
phosphorus magnesium iron
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functions of phosphorus? (4) |
-bone/teeth structure with Ca -phospholipid bilayer in cell membranes 0cyclic AMP, ADP, ATP -serum acid buffer |
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function of magnesium? (3) |
-regulate DNA/RNA synthesis -cardiac electrical conduction -ties into proper K in blood |
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primary role of iron? stored where?
deficiency causes? |
oxygen-binding molecule hemoglobin (in all RBCs)
20% of iron stored in liver, spleen, bone marrow
iron deficiency anemia |
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anemia?
impact of iron deficiency anemia? symptoms? |
loss of RBC
RBC oxygen carrying capacity diminished
fatigue, dizziness, headache, poor exercise tolerance, paleness |
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what are the two types/sources of iron?
impact for vegetarians? |
non-heme iron: plants; has poor absorption in the gut (2-5%)
heme iron: animal; gut absorption is better (10-35%)
vegetarians are at risk for iron deficiency |
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what are the 4 electrolytes? |
sodium potassium chlorine magnesium |
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what do the electrolytes do? |
-facilitate electrical charge gradient across cell membrane -nerve conduction -muscular contraction -body water balance
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how do electrolytes influence body water balance? |
facilitate movement of water/ions/waste in and out of cells
*control intravascular and extravascular hydration* |
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recommended daily intake of electrolytes? |
Na= 2400 mg K= 4700 mg Cl= 3400 mg
^^see 2:1 ratio of K:Na |
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how does sodium contribute to hypertension?
influences? |
water follows sodium! and blood pressure is somewhat dependent on blood volume
plasma Na is controlled by aldosterone (tells kidney to conserve sodium) BUT high Na diet blunts aldosterone release so excess Na in urine
some are more "salt-sensitive" and possibly genetic links |
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hypertension # |
>140 mmHg/90 mmHg |
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what are trace minerals? how get them?
examples? |
minerals required in minute quantities good diet provides all of them
copper zinc manganese chromium |
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how can too much trace minerals harm you? |
malabsorption or chemical interaction with another mineral so possibly a pathology as a result! |
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what is excreted in sweat?
how much water lost in sweat in a long event? salt depletion? |
water, trace minerals, electrolytes
5 kg water (8 g salt depletion) |
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what % of the body is water?
how much muscle weight is water? fat weight?
average body has _____ L water? |
40-70% of total body mass
65-75% 10%
42! |
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where is body water stored (at the cell level)? |
60% intracellularly 40% extracellularly-vascular volume and intersititial fluid (inbetween cells) |
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1st space 2nd space 3rd space |
in cells inside blood vessels/lymphatics intersitital space |
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where is most water loss from sweat from? |
extracellular space |
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roles of water in the body? (5) |
1) universal solvent to dissolve soluble waste products 2) transport medium 3) joint cushion/lubrication when with other molecules 4) tissue turgor-noncompressible fluid 5) reglate body temp-high specific heat |
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euhydration hypohydration hyperhydration |
even level of hydration dehydration/hypovolumia hypervolumuia (decrease electrolyte content and possibly momentary hypertension) |
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water intake amount? thirst mechanism adaquate predictor of water balance? |
2.5 L/day in climate controlled if sedentary
no, usually 1-2 L behind |
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water in exercise!
lb body weight lost during exercise=
repletion via? |
sweating is bodys head regulatory mechanism during exercise
450ml water, 700 mg salt
plain water or sports drinks if over 4 hours |
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what would happen if no salt repletion over 4 hrs? condition? |
plain water rehydraiton may cause dilution of plasma electrolytes...get hyponatremia-low sodium in the blood; water diffuse into brain and cause swelling |
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water needed during exercise (#'s) |
400-600 ml water 2-3 hrs before exercise 150-300 mL water 30 min before exercise 1000 mL during exercise plain water (over 15 min intervals) 1/2 tsp salt per 32 fluid oz and maybe some glucose
AVOID SALT RESTRICTION |
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BMR
how to calculate?
thermal effect of food? |
basic metabolic rate-calories needed to keep you alive per day if your body is at rest
lots of charts out there
10% BMR+active energy requirement-energy required to ingest, digest, absorb, store, eliminate food |
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what is the BMR for males/females |
2000 kcal females 3000 kcal males
*most athletes dont need over 4000 kcal/day* |
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how much of your lipids should be unsaturated fatty acids?
where should your carbs come from? |
70% at least
whole grains, fruit, veggies and 20 g fiber along with it! |
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"my plate" gov %'s |
30% grains 30% veggies 20% fruit 20 % protein +dairy in cup |
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carb uptake timing if your going to exercise? |
PRE, eat > 60 min before exercise
DURING, 60 g carbs/hour during high intensity (marathons)
POST, carb rich, high glycemic foods to replenish glycogen |
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how fast do glycogen stores replenish? takes how long? |
5-7% per hour with optimal carb intake can take about 20 hrs to refill all stores |
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pre comp meal should have? eat how long before? |
high carbs (150-300 g) low lipids/proteins eat 3 hours before |
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what is the glycemic index?
which are good for recovery? for pre-exercise meals? |
rate at which glucose enters bloodstream following ingestion of carb food source
high glycemic index low glycemic index |
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SO IN ALL, how does rehydration/refueling help during exercise? |
prevent performance loss due to dehydration/electrolyte loss
glucose repletion during exercise spares glycogen stores so extend workout time to exhaustion
electrolyte repletion preserves thirst mechanism and prevents hyponatremia |
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how do gastric emptying rates affect things? (4 examples) |
affect nutrient and fluid absorption rates by small intestine
REDUCE EMPTYING RATE: -high intensity exercise (>75%) -caloric content [increased] -pH -osmolality [high solute concentration] -dehydration
INCREASE EMPTYING RATE: -volume
INCREASE FLUID ABSORPTION: -carbs -sodium -osmolality (hypotonic NaCl-glucose fluids)
**check slide 79** |
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ethanol and caffine are ______ |
poor hydrators! cause diuresis |
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what is the "winning formula?" |
5-8% carb with electrolytes in water is good for 1-2 hrs
high intensity exercise AND/OR hot environment use 4-5% carbs
cooler environments? 15% carb solution
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what kind of carbs to use for the winning formula? |
glucose, sucrose, starch *not fructose! GI distress* |
