Exercise helps prevent weight regain after dieting by reducing appetite and by burning fat before burning carbohydrates, according to a new study with rats. Burning fat first and storing carbohydrates for use later in the day slows weight regain and may minimize overeating by signaling a feeling of fullness to the brain.
The University of Colorado Denver study also found that exercise prevents the increase in the number of fat cells that occurs during weight regain, challenging the conventional wisdom that the number of fat cells is set and cannot be altered by dietary or lifestyle changes.
These coordinated physiological changes in the brain and the body lower the 'defended' weight, that is, the weight that our physiology drives us to achieve, and suggest that the effects of exercise on these physiological processes may make it easier to stay on a diet.