Diet-induced obesity in mice can be treated without energy restriction using exercise and/or a low fat diet

Diet-induced obesity was treated with a high carbohydrate, low fat diet and/or increased voluntary exercise in mice. All mice had free access to food and water during the two stage experiment. In Stage 1, 20 female mice were fed a high carbohydrate diet and 50 were made obese by consumption of a diet providing 40.8% of energy from fat. At the end of Stage 1, obese mice had significantly greater body fat stores (22.9 +/- 0.9 g/100 g body wt) than mice fed the high carbohydrate diet (12.9 +/- 1.2) (P < 0.001), yet there was no significant difference in lean body mass. In Stage 2, half of the mice were given activity wheels to increase their voluntary activity and half of the obese mice were switched to a high carbohydrate diet resulting in six groups with treatment designations of obese or lean; exercise or nonexercise, and carbohydrate or fat diets. Body fat was significantly reduced by consumption of the high carbohydrate diet (P < 0.005) and by exercise (P < 0.001), but neither treatment affected lean body mass. Exercising mice consumed significantly more energy than nonexercising mice, yet experienced a decrease in body fat and energy stores.(ABSTRACT TRUNCATED AT 250 WORDS)