Effect of two different diets and exercise training on weight gain in rats

Objective. - The prevalence of obesity and associated health conditions is increasing, which underscores the importance of developing effective strategies to counteract overweight. It is well known that diet and exercise are the two main ways to control weight gain. It is not known, however, how physical exercise can prevent overweight when associated with different types of diets. To test this, we compared the combined effect of 30 days of two different diets and exercise training on total weight change in rats. Material and methods. - The study was carried out on four groups of rats (n=12), 6 weeks old; the standard diet sedentary group (SS), standard diet with exercise (SE), high-protein diet with exercise (PE) and high-fat diet with exercise (FE). Results. - Significant reductions in weight gain and in food intake were observed with training (P<0.001). Body weight was decreased by protein diet (P<0.01) and maintained in trained rats receiving fat diet. Fat diet increased both insulin concentrations (P<0.05), glycaemia (P<0.001) and muscle glycogen (P<0.01). Conclusion. - Our results demonstrated the positive effect of physical exercise on reducing both food intake and weight gain in the case of standard diet. We showed, as well, that combined effect of exercise training with hypocaloric diet (protein diet) induced the less weight gain. Whereas, in combination with hypercaloric diet (Fat diet), physical exercise prevented overweight. Fat diet disrupts, also, carbohydrate and fat metabolisms. (C) 2011 Elsevier Masson SAS. All rights reserved.