Effect of voluntary exercise on physiological function and feeding behavior of mice on a 20% casein diet or a 10% casein diet.

The effects of voluntary exercise on growth and food intake, body composition, organ weight, and fatty acid composition of adipose tissue of mice fed on a 20% casein diet or a 10% casein diet were examined. The weight gain was greater for the 20% casein nonexercise group (20% NE) than that for the 20% casein exercise group (20% E), 10% casein exercise group (10% E) and 10% casein nonexercise group (10% NE). There were no significant differences between the groups except the 20% NE. In 20% E and 10% E, body fats decreased markedly. On the other hand, a very high ratio of protein was present in the body composition of both groups. In the 20% and 10% casein diet groups, food intake was increased by voluntary exercise, but there was no significant difference between 10%E and 10% NE except occasional periods during these experiments. After 6 weeks of age, 10% E had a tendency to undertake more voluntary exercise than 20% E, though the difference was not statistically significant. Development of the heart and gastrocnemius muscles was accelerated by voluntary exercise and epididymal fat tissue was markedly decreased.