Washington, Sep 2 - Exercise helps prevent weight regain after dieting by cutting down appetite and burning fat, says a new study.

Burning fat first and storing carbohydrates for use later in the day slows weight regain and may minimise overeating by signalling a sense of fullness to the brain.

The University of Colorado-Denver (UC-D) study also found that exercise prevents the increase in 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, said an UC-D release.

Paul S. MacLean, Janine A. Higgins, Holly R. Wyatt, Edward L. Melanson, Ginger C. Johnson, Matthew R. Jackman, Erin D. Giles, Ian E. Brown and James O. Hill, all from UC-D, conducted the study.

These findings were published in the American Journal of Physiology - Regulatory, Integrative and Comparative Physiology.