Compensatory eating behaviors in male and female rats in response to exercise training.

Exercise is often used as a strategy for weight loss maintenance. In preclinical models, we have shown that exercise may be beneficial because it counters the biological drive to regain weight. However, our studies have demonstrated sex differences in the response to exercise in this context. In the present study, we sought to better understand why females and males exhibit different compensatory food eating behaviors in response to regular exercise. Using a forced treadmill exercise paradigm, we measured weight gain, energy expenditure, food intake in real time, and the anorectic effects of leptin. The 4-wk exercise training resulted in reduced weight gain in males and sustained weight gain in females. In male rats, exercise decreased intake, whereas it increased food intake in females. Our results suggest that the anorectic effects of leptin were not responsible for these sex differences in appetite in response to exercise. If these results translate to the human condition, they may reveal important information for the use and application of regular exercise programs.