NEW YORK, July 24 (Praxis Press) Whether weight loss resulting from exercise or diet causes the same improvement in health is unclear. It is also unknown whether exercise without weight loss provides health benefits for people who are overweight. To compare the effects of diet-induced weight loss with those of exercise-induced weight loss, and the effects of an exercise program without weight loss in obese persons, Ross and colleagues studied 52 obese men. The study participants were randomly assigned to four groups: weight loss by diet, exercise intended to produce weight loss, exercise not designed to produce weight loss, or a control group. At the beginning of the study and after 12 weeks, the researchers measured various fitness and weight parameters. Men in both the diet and the exercise-weight loss programs lost an average of about 16 pounds. Weight did not change in the control group or in the group assigned to exercise without weight loss. Body fat decreased in both weight loss groups, but men in the exercise-weight loss program lost more body fat than men in the diet-weight loss program. Exercising without dieting was shown to be as effective for modest weight loss as dieting without exercising.