Modulation of the exercise and retirement effects by dietary fat intake in hamsters

An experiment was conducted to determine the effects and interactions of exercise-retirement and dietary fat intake on body composition and hepatic lipogenic enzyme activities in hamsters. Forty-eight adult female hamsters were randomly allotted to eight groups of six each for a 40-d experiment. Exercise was in the form of voluntary wheel-running. Four groups served as either exercise or sedentary controls and were fed either a low or a high fat diet for 40 d, in a factorial fashion. Another four groups had access to exercise for 32 d and were then retired for 8 d. Of these four groups, two were fed either the low or high fat diet for the entire 40-d period; the other two were changed to the other diet on d 32. Results showed that compared to sedentary hamsters, exercise hamsters had greater body weight gain but less body fat content and hepatic lipogenic enzyme activities. Under both sedentary and exercise conditions, high fat-fed hamsters had lower hepatic lipogenic enzyme activities and less body fat content than low fat-fed hamsters. Upon retirement, high fat feeding led to a faster increase in body fat especially in previously high fat-fed hamsters. Results of this study suggest that dietary fat intake can significantly modulate the exercise and retirement effects with respect to body weight gain and body fat content.