digital vs analog

Consider 10 factors w/c contribute to any event A. Let 5 of these factors be sufficient conditions to make event A happen. Any 4 of them together will imply a non event A. This fits the model that some people have no condition A while still practising factors to contribute to condition A. It appears a lot of human conditions are digital ie an all or nothing response

physiology of CCK in saiety

Protein and fat chyme -> CCK secretion from duodenum->reduces gastric emptying-> hunger suppression(1) . Also CCK-> NTS in brain stem-> satiety (2). (1) Am J Physiol Regul Integr Comp Physiol 252: R353-R360, 1987 (2) Sci. Am. Sept 2007

mechanism of lipoprotein lipase

The job of determining how fuels (glucose and fatty acids) will be used, whether we will store them as fat or burn them for energy, is carried out primarily by the hormone insulin in concert with an enzyme known technically as lipoprotein lipase - LPL, for short. (Sex hormones also interact with LPL, which is why men and women fatten differently.)

In the Eighties, biochemists and physiologists worked out how LPL responds to exercise. They found that during a workout, LPL activity increases in muscle tissue, and so our muscle cells suck up fatty acids to use for fuel. Then, when we're done exercising, LPL activity in the muscle tissue tapers off and LPL activity in our fat tissue spikes, pulling calories into fat cells. This works to return to the fat cells any fat they might have had to surrender - homeostasis, in other words. The more rigorous the exercise, and the more fat lost from our fat tissue, the greater the subsequent increase in LPL activity in the fat cells. Thus, post-workout, we get hungry: our fat tissue is devoting itself to restoring calories as fat, depriving other tissues and organs of the fuel they need and triggering a compensatory impulse to eat. The feeling of hunger is the brain's way of trying to satisfy the demands of the body. Just as sweating makes us thirsty, burning off calories makes us hungry.

AHA/ACSM 2007 on exercise

Just last month 2007, the American Heart Association and the American College of Sports Medicine published joint guidelines for physical activity and health. 'It is reasonable to assume that persons with relatively high daily energy expenditures would be less likely to gain weight over time compared with those who have low energy expenditures. So far, data to support this hypothesis is not particularly compelling.' In other words, despite half a century of efforts to prove otherwise, scientists still can't say exercise will help keep the pounds off. ...More

effect of exercise on primary prevention of cvd

A systematic review of the evidence on the effects of physical activity found that people who exercise (those who undertake moderate levels of activity daily or almost daily, e.g., walking) typically experience 30%–50% reductions in relative risk of coronary heart disease compared with people who are sedentary after adjustment for other risk factors [1]. Moderate-to-high levels of physical activity are associated with reduced risk of coronary heart disease and stroke. The absolute risk of sudden death after strenuous activity is small (it is greatest in people who are usually sedentary).

observational study shows fruits/veggies lower cvd

In their systematic review of the evidence on the effects of eating more fruit and vegetables for primary prevention of cardiovascular disease, Foster and colleagues found no RCTs [1]. They found three systematic reviews of observational cohort studies, all of which found a protective effect against ischemic heart disease.

sugars up TG and lower HDL

High intake of added sugars is associated with increased risk for low HDL cholesterol and high triglycerides, according to a JAMA report.


Researchers studied some 6000 adults participating in the National Health and Nutrition Examination Survey (NHANES). Consumption of added sugars (e.g., high-fructose corn syrup and other caloric sweeteners used in prepared foods) was calculated from 24-hour dietary recalls.


In adjusted analyses, the odds of having low HDL cholesterol and high triglycerides rose significantly with increasing intake of added sugars. For example, compared with adults who got less than 5% of their total energy intake from added sugars, those getting 17.5%–25% of their energy from added sugars were about twice as likely to have low HDL levels.


The researchers found no consistent association between added sugars and LDL cholesterol.