December 19, 1998
Web posted at: 8:02 a.m. EDT (1202 GMT)

From Medical Correspondent Holly Firfer

(CNN) -- As the fight against fat continues, researchers have pinpointed another hormone that could control and possible reduce your appetite.

The melanin controlling hormone, or MCH, is released into the system to tell the body it's time to eat. When this hormone is blocked, the desire to eat is dramatically reduced.

In a study published in the journal Nature, researchers genetically engineered mice without MCH and found they eat much less.

"It's 25 percent leaner than its brothers and sisters," said researcher Dr. Terry Maratos-Flier of the Joslin Diabetes Center. "That mouse also seems to have a higher metabolic rate, so it also seems to burn off more energy."

MCH is a function of survival. Animals in the wild often cannot find food for days. The hormone fuels their desire to forage and keeps them eating once they do find food.

Although the research is in mice, scientists say this finding may be helpful in treating obesity in humans because the influence of MCH on the brain is the same in both mice and people.

"The ideal patient would be someone who has an increased appetite, because presumably if we were blocking the action of MCH, we would be blocking the motivation to open the refrigerator door and start eating," Maratos-Flier said.

Researchers reported no negative side effects due to the absence of MCH. The usual problems associated with being too thin, such as longevity, fertility and a lack of energy, were not found.