Dec. 8 (Bloomberg) — Harvard University researchers say they're one step closer to creating a pill that may someday replace the treadmill, thanks to a breakthrough that can change the way energy-storing white fat cells behave.

The laboratory work enables scientists to more easily manipulate white fat cells, the bad kind that stores energy for later use and contributes to obesity and diabetes, according to the report in Nature Cell Biology. The scientists screened about 1,000 compounds and found two that make the white fat cells act more like their brown cousins, which burn excess energy rather than store it.

"What we wanted to do is take the white fat no one wants, especially post-holidays, and turn it into the fat everyone wants, the brown fat," said senior author Chad Cowan, a faculty member at the Harvard Stem Cell Institute. The results suggest "you could someday come up with a small molecule that might be a pill that would replace a treadmill in terms of its ability to burn fat or burn calories," he said in a telephone interview.