They also help regulate appetite and keep the brain and nervous system running optimally.

Sleep plays a vital role in regulating metabolism and appetite.

One role of leptin is to regulate appetite by signalling to the brain that the animal has had enough to eat.

Many of the chemicals in the brain that bring on psychiatric problems also regulate appetite.

Insufficient shut-eye appears to increase production of the stress hormone cortisol, which regulates appetite.

Serotonin is a chemical messenger that helps regulate mood, appetite, and sleep.

Circulating leptin levels give the brain input regarding energy storage, so it can regulate appetite and metabolism.

It is responsible for regulating appetite and production of body fat.

Japanese scientists discovered in 2006 that it is responsible for regulating appetite and production of body fat.

Scientists said that they did not yet know whether the three substances might work together to regulate appetite.