Jason Fung

The standard prescription for weight loss is “Eat Less, Move More.” It sounds perfectly reasonable. But why doesn’t it work? Perhaps people wanting to lose weight are not following this advice. The mind is willing, but the flesh is weak. Yet consider the self-discipline and dedication needed to complete an undergraduate degree, medical school, internship, residency and fellowship. It is hardly conceivable that overweight doctors simply lack the willpower to follow their own advice.

Prior to puberty, boys and girls average the same body-fat percentage. After puberty, women on average carry close to 50 percent more body fat than men. This change occurs despite the fact that men consume more calories on average than women. But why is this true?

Caloric intake and expenditure are intimately dependent variables. Decreasing Calories In triggers a decrease in Calories Out.

We consciously decide to eat in response to hunger signals that are largely hormonally mediated. We consciously stop eating when the body sends signals of satiety (fullness) that are largely hormonally mediated.

Reduced metabolism and the increased hunger are not the cause of obesity—they are the result.

Exercise is like brushing your teeth. It is good for you and should be done every day. Just don’t expect to lose weight.

You cannot make up for dietary indiscretions by increasing exercise.

Diet accounts for 95 percent of the grade and exercise for only 5 percent.

It would be later confirmed that hypothalamic damage resulted in intractable weight gain in humans.

OBESITY DEVELOPS WHEN the hypothalamus orders the body to increase fat mass to reach the desired body set weight.