Exercise Trumps Diet for Weight Loss

By Sara Goudarzi
LiveScience Staff Writer

Hitting the gym is a better way to trim down than agonizing over portion size, a new study suggests.

Although the ultimate goal of using more energy than what you ingest can be achieved with dieting or exercise, working out has more perks.

Those who exercise tend to be stronger, have more muscle mass, and an increased aerobic capacity. Dieters, however, tend to lose muscle mass and strength.

"If push comes to shove and somebody wants to know if they should diet or exercise to lose weight, I would suggest exercise, provided they are willing to put in the extra time and effort and not offset the gains they make by eating more," said study lead author Edward Weiss, a researcher at Saint Louis University's Doisy College of Health Sciences.

Weiss and his colleagues studied 34 people between the ages of 50 and 60 who were in the high end of normal weight or overweight. Of the participants, 18 dieted while 16 exercised.

The dieters cut out their calorie intake by 16 percent the first three months and 20 percent for the next nine months. Similarly the exercise group worked out to burn 16 percent more calories the first three months and 20 percent the following nine months.

Both groups lost around 9 to 10 percent of their body weight. But the dieters lost muscle mass, while the exercisers did not.

"It's important that dieting not be seen as a bad thing because it provides enormous benefits with respect to reducing the risk of disease and is effective for weight loss," Weiss said. "Furthermore, based on studies in rodents, there is a real possibility that calorie restriction provides benefits that cannot be achieved through exercise-induced weight loss."

The study is detailed in an online edition of the Journal of Applied Physiology.