Term
what is obesity? why does it occur? |
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Definition
intake of more calories than expenditure of food. we are genetically programmed to store fat in order to survive and reproduce. exacerbating factors include lack of physical exercise, plentiful inexpensive food, and caloric imbalance |
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Term
why is it wrong to define obesity as a disease? |
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Definition
shifts responsibility to physician, not pt. pt. should be stongly motivated to not overeat/overconsume calories |
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Term
why is there a push for obesity to be categorized as a disease? |
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Definition
so that insurance companies will pay for tx |
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Term
what is an example of incremental weight gain? |
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Definition
avg. woman in US gains 25 lbs from age 25-65 |
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Term
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Definition
peptide hormone released by the stomach that affects the hypothalamus, stimulates 2 neuropeptides: Agouti related protein, (AgRp) and Neuropeptide, (NPY, Y stands for tyrosine) |
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Term
what do Agouti related protein, (AgRp) and Neuropeptide, (NPY) do? |
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Definition
they are orexogenic, stimulate appetite by synthesizing other NTs to go to the GI and affect motility |
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Term
how can ghrelin levels be regulated? |
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Definition
bariatric sx, reduction of stomach vol, lowers blood ghrelin conc. |
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Term
what are the 2 main anorexogenic, (appetite decreasing), hormones? where are they made? |
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Definition
insulin from the pancreas, and leptin from adipose tissue |
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Term
what happens if you destroy the leptin gene? what happens if you inject exogenic leptin into a mouse or a human? |
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Definition
destroy the leptin gene, a mouse will become obese, inject a mouse with exogenic leptin, it will lose weight, though the same result cannot be repeated with humans |
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Term
where are the receptors for leptin and insulin? what happens when they bind? |
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Definition
they bind to receptors in the hypothalamus, and stimulate anorexogenic NTs such as alpha melanocyte stimulating hormone, (alpha-MSH), (it's receptors are in the hypothalamus) |
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Term
where does alpha melanocyte stimulating hormone come from? |
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Definition
Proopiomelanocortin, (POMC), long peptide when cleaved gives a variety of products, including alpha-MSH |
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Term
what is the action of alpha melanocyte stimulating hormone? |
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Definition
alpha melanocyte stimulating hormone inhibits the action of orexigenic neurotransmitters, Agouti related protein, (AgRp), and Neuropeptide Y, (NPY) |
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Term
what is PYY, where does it come from, what does it do? |
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Definition
PYY is a hormone produced in the large intestine that inhibites orexigenic signals including the receptor NPY, and signals from the intestines -> stimulated hypothalamus |
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Term
what is the effect of dopamine and seratonin on appetite? |
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Definition
they cause a decrease in feeding/wt gain |
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Term
what increases with increased dopamine? what has been associated with low dopamine? |
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Definition
feelings of pleasure. addiction to narcotics, gambling, and overeating are associated with pts in low dopamine |
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Term
excess of any fuel, including protein will result in? |
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Definition
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Term
obesity is associated with metabolic syndrome, which is associated with what 4 conditions? |
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Definition
central obesity, (pear shape), inefficient insulin regulation of carbs, (often diabetes), HTN, (more fat=more pressure on CV), dyslipiemia, (increase in "bad lipids", cholesterol, LDLs) |
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Term
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Definition
amount of wt per unit of surface |
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Term
why is no diet ultimately effective? |
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Definition
no diet can work long term |
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Term
what is the pritikin diet? will you lose weight? |
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Definition
low fat, high carbs, high fruits/vegetables. developed as anti-sclerotic diet, reduce levels of insoluble lipids, (cholesterol, oxidized lipids), which form "fatty streaks" in vasculature, some of which are congential. not intended as a weight loss diet. |
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Term
what is the atkins diet? what was it designed to do? |
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Definition
high fat, high protein, low->no carbs, pts will lose weight on this diet |
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Term
b/c the adkins diet cuts out carbs what is necessary to do? |
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Definition
need to supplement w/vitamins |
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Term
why is the adkins diet effective in promoting weight loss? |
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Definition
it is a hypocaloric diet in disguise, the metabolic products from protein/fat supress appetite |
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Term
how do high fat and protein levels affect glucagon? |
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Definition
glucagon levels rise, stimulates catabolic processes, (b/c not much glucose) |
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Term
what did the long term study find out about how the adkins diet affects people over a year? |
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Definition
nontoxic, people live off ketone bodies, no increase in cholesterol/triglycerides. the weight loss will level off with a slight increase at the end. |
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Term
what was found in mice on the adkins diet in comparison to mice w/typical western diet, and pritikin diet? |
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Definition
adkins diet mice had significant increase in atherosclerosis |
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Term
what is the south beach diet? |
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Definition
moderate amounts of fats and proteins, emphasis on "good fatty acids", (no saturated or trans), use carbs with low glycemic index, (reduce insulin "burst"). excercise is essential. |
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Term
how does exercise help regulate diet? |
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Definition
AMP regulated protein kinase B increases catabolic processes such as lipolysis, glycogenolysis and decreases anabolic processes such as fatty acid and cholesterol synthesis. excercise makes ADP, 2 of which is converted to 1 ATP and 1 AMP by adenyl kinase -> thus excercise increases AMP conc for protein kinase B |
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Term
where does resisitance to lose weight come from biologically according to once theory? |
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Definition
genes and the brain try to maintain a set point of weight for the body |
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Term
what is an example of evidence pertaining to adipocytes for the set weight point theory? |
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Definition
adipocytes can only get so big before their number has to be increased to keep up with input, however, you can never lose adipocytes once you create them. |
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Term
what are 4 examples of evidence for the set weight point theory? |
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Definition
leptin, insulin conc, ghrelin, free FAs |
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Term
why is the set weight point situation a problem with childhood obesity? |
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Definition
they will be stuck with the same number of adipocytes for the rest of their life |
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Term
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Definition
weight loss drug, phosphorylation decoupler, converts food -> heat, eventually fatal |
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Term
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Definition
anti obesity drugs, fenfluramine and phentermine, NTs to depress appetite, increase satiety -> can cause heart failure |
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Term
how do amphetamines help cut weight? |
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Definition
sympathetic amine that stimulates CNS activity, depresses appetite |
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Term
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Definition
powerful stimulant which increases thermogenesis via decoupling of oxidative phosphorylation, also associated with heart disease |
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Term
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Definition
dopamine and seratonin receptor blocker, good drug, but insignificant weight loss which is only dependent on drug use |
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Term
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Definition
weight loss drug which is an inhibitor of gastric and pancreatic lipase -> pt cannot digest fats, get oily feces and bloating |
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Term
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Definition
canabinoid receptor blocker, developed to help people stop smoking, was also found to reduce obesity. not approved by the FDA |
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Term
what are 4 major pathological consequences of obesity? |
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Definition
insulin resistance, (related to mult pathways), cardiovascular disease, (peripheral resistance to circulation, high Na+, and increased LDL/VLDL, decreased HDL), pulmonary disease, (breathing rate increases with weight strain/heart rate), and some kinds of CA, (can be gender specific) |
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Term
what are low risk behaviors for avoiding obesity? |
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Definition
bmi <25, high fiber, polyunsat fatty acids, (needed for prostaglandins/leukotrienes), low trans fats/low glycemic index, mod. physical activity, and no smoking |
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