We've all heard scantily clad spokespeople make bogus claims about instant weight-loss supplements on late-night television. But in today's early online edition of the Proceedings of the National Academy of Sciences, researchers describe what sounds like the real dealfor mice, anyway. Harvey Lodish of the Whitehad Institute for Biomedical Research and his colleagues have discovered a new compound that causes profound weight loss in mice fed an unlimited diet high in fat and sugar. The compound, called gAcrp30, is a fragment of the Acrp30 protein. Most weight loss drugs work by absorbing fatty acids in the intestine or by inhibiting the breakdown of fatty acids so that they are excreted rather than stored. In contrast, gAcrp30 actually causes muscle to burn fatty acids faster.

Mice treated with the compound showed significantly reduced levels of free fatty acids, as well as lower glucose and triglyceride levels. Moreover, daily low doses of gAcrp30 enabled the mice to keep the weight off, despite their cafeteria diet. Though the results are promising, don't wait up nights looking for a phone number to call now. "Much further research is needed to determine whether this substance can be used in man as an aid in weight loss," Lodish remarks. "Such a therapy is urgently needed by the many thousands of obese patients who suffer from many related health problems such as diabetes."