In Brief:
- Weight control is not simply a matter of willpower. Genes help determine the body's "set point," which is defended by the brain.
- Dieting alone is rarely successful, and relapse rates are high.
- Moderate exercise, too, rarely results in substantive long-term weight loss, which requires intensive exercise.
"...Second, scientists recently have come to understand that the brain exerts astonishing control over body composition and how much individuals eat. “There are physiological mechanisms that keep us from losing weight,” said Dr. Matthew W. Gilman, the director of the obesity prevention program at Harvard Medical School/Pilgrim Health Care.
Scientists now believe that each individual has a genetically determined weight range spanning perhaps 30 pounds. Those who force their weight below nature’s preassigned levels become hungrier and eat more; several studies also show that their metabolisms slow in a variety of ways as the body tries to conserve energy and regain weight. People trying to exceed their weight range face the opposite situation: eating becomes unappealing, and their metabolisms shift into high gear.
The body’s determination to maintain its composition is why a person can skip a meal, or even fast for short periods, without losing weight. It’s also why burning an extra 100 calories a day will not alter the verdict on the bathroom scales. Struggling against the brain’s innate calorie counters, even strong-willed dieters make up for calories lost on one day with a few extra bites on the next. And they never realize it. “The system operates with 99.6 percent precision,” Dr. Friedman said...."
Here's an interesting article on obesity I read recently.
