With hormone's help, thin is in; Discovery can control desire to eat; unknown if it will work with humans.(Main)

Byline: DENISE GRADY New York Times

Hungry or full, fat or thin: it is mostly a matter of hormones, dozens of them, carrying messages between the digestive tract, the fat cells and the brain. Eat. Don't eat. Burn calories. Store fat.

Today , researchers at Stanford University are reporting that they have found a previously unknown member of this chemical cascade, a hormone with a much-coveted power: It sharply reduces the desire to eat.

The new substance, which the scientists named obestatin (OHB-statin), is made in the stomach and small intestine, and it seems to prompt the brain to send out a signal that says "eat less."

Mice given the …