Researchers are one step closer to developing a pill that may one day “replace the treadmill” for controlling obesity.

Scientists at the Harvard Stem Cell Institute have identified two compounds that can turn white fat cells, the so-called “bad” kind of fat cells, into brown fat cells, or what are known as “good” fat cells.

White fat cells are linked to the development of obesity, type 2 diabetes and other conditions, including heart disease. The body stores energy in white fat cells, which it produces when it takes in more calories than it burns.

Brown fat cells burn that excess energy, thereby reducing the number of white fat cells.

Brown fat cells also lower levels of triglycerides, a type of fat found in the blood, and reduce insulin resistance, which is associated with type 2 diabetes.

The findings are published in a report released Monday in an online edition of the journal Nature Cell Biology.

Scientist Chad Cowan of the Harvard Stem Cell Institute (HSCI) cautioned that the research is in its early stages and a safe and effective medication may be a long way off.

He also noted that the two compounds target a molecule that also plays a role in the body’s inflammatory response. The concern, he said, is that a medication developed to attack white fat cells could also attack a patient’s immune system.

“So if you administered (the compounds) for a long time, the person taking them could become immune-compromised,” Cowan said in a statement issued by the HSCI.

However, the early findings are promising.

Other compounds have had the same effect on white cells in animal studies, but the effect goes away when the compounds are no longer administered, Cowan said.

But these new compounds offered a “stable conversion” of white fat cells to brown.

“You’re constantly replenishing your fat tissue,” Cowan said, “so if you were on a medication to convert the cells, each new fat cell would be more metabolically active and would convert to brown fat over time.”

This would reduce the likelihood of developing type 2 diabetes or any other condition related to a buildup of fat, he said.

The initial research was conducted in collaboration with drug manufacturer Roche Pharmaceuticals. However, that relationship has ended and the research team is seeking a new pharmaceutical company to partner with and continue its research into the two compounds.