Regulation of the body fat percentage in developmental-stage rats by methylxanthine derivatives in a high-fat diet.

We investigated the regulatory effects of structural differences among methylxanthine derivatives on the elevation of body fat percentage in developmental-stage rats. Caffeine, theophylline and theobromine were used as the methylxanthines. High-fat diets (20% lard) containing each methylxanthine (0.025%) were administered to male Sprague-Dawley rats for 12 weeks, with the result that the body fat percentage was generally reduced in each methylxanthine-fed group. The abdominal adipose tissue weight in the caffeine group was also significantly lower than that in the control group, the serum cholesterol and triglyceride levels in the caffeine group also being significantly lower than the levels in the control group. The study results suggest that caffeine could contribute most to preventing arteriosclerotic diseases.