"We might not have any magic bullet, " for obesity said Dr. Gene-Jack Wang, chair of medical research at Brookhaven National Laboratory.

CNN: Why isn't there a safe weight-loss pill?

Together, the compounds affect both appetite or satiety and motivation, or the drive to eat, says Gene-Jack Wang, MD, a senior scientist with Brookhaven National Laboratory in Upton, New York.

CNN: Combo of old drugs offers new hope in obesity fight

In a lab at Brookhaven National Laboratory on Long Island, Gene-Jack Wang is injecting overeaters with a radioactive sugar solution and putting them into a positron-emissions tomography machine to see how their brains react to food.

FORBES: Food on the Brain