A study was conducted at Pittsburg University aiming at confirming the reports about the slimming properties of pyruvic acid. Healthy mature overweight women were qualified for the study and were divided into two groups. Both groups were on a diet with reduced intake of calories and fat. After two week the women from the first group began taking pyruvic acid whereas the women from the other group were given placebo. After another four weeks of dieting and supplementation it turned out that the women from the pyruvic acid groups on average lost 37% of weight more than the women from the placebo group. However, another observation seems more valuable. In the pyruvic acid group, the weight loss at the cost of the loss of fatty tissue on average was 50% higher than in the placebo group. The observations confirm the view that the supplementation of pyruvic acids, e.g. creatine pyruvate, can facilitate fat reserve reduction with simultaneous protection of proteins responsible for fitness and beauty.