The effects of ephedra free stacker 2 on metabolic rate and weight of Long-Evans rats.

Dietary supplements that claim to enhance metabolism are continually introduced to the health food market without proof of effectiveness. A main ingredient in Stacker 2, an over-the-counter herbal supplement, is caffeine, primarily in the form of anhydrous caffeine and kola nut seeds. Previous studies completed have shown that caffeine has thermogenic properties that increase metabolism and aid in weight loss. The experimental rats were chosen for their genetic predisposition for overeating. The rats were administered Stacker 2 containing 200 mg of anhydrous caffeine and 198 mg of a proprietary blend of herbs including kola nut seeds. The pills were mixed into ground up rat chow for the duration of the four-week experiment. The rats were kept in environmentally controlled conditions following the guidelines of the animal welfare committee. The weights and metabolic rates of the rats were measured initially and weekly. Metabolic rate was determined by using a respirometer to measure oxygen utilization. The statistical analysis shows that the Stacker 2 group had a significantly higher metabolic rate (p<.01) at the conclusion of the experiment and significantly lower rate of weight gain (p<.05) compared to the control rats.

* Cox, M.C., * M.C. Peterson and * D. Johnson. Department of Biological Sciences, Northwest Missouri State University.