Dairy and Exercise as a Novel Treatment Strategy for Obesity
The purpose of this investigation was to compare the individual and combined effects of dairy and endurance exercise training in reducing weight gain and adiposity in a rodent model of diet-induced obesity. A 6-week feeding intervention of a high fat, high sugar diet was used to rapidly induce obesity in male Sprague Dawley rats (6-weeks of age). Rats were then assigned to one of four weight-matched groups for 6 weeks: 1) casein-sedentary 2) casein-exercise 3) dairy- sedentary 4) dairy-exercise. The exercise training intervention took place 5 days/week (60 minutes of treadmill running: 20m/min, 10% incline). The effects of exercise training in combination with dairy protein were greater than either intervention alone in attenuating increases in weight gain. Adipose tissue and liver mass were reduced to similar extents with casein-exercise, dairy-sedentary and dairy-exercise. Differences in weight gain were not explained by food intake, total energy expenditure nor substrate oxidation. The total amount of feces excreted was higher in the dairy- sedentary group, and this was associated with an increase in the total amount of lipid excreted compared to the casein-sedentary group. This study provides novel evidence that dairy protein attenuated weight gain in obese rats to a similar extent as exercise training, and appeared to exert a partial additive effect when combined with exercise. While exercise training reduces weight gain through increases in energy expenditure with each bout of exercise, dairy would appear to increase the amount of lipid excreted in the feces.