The Yin and Yang of Appetite Control: Leptin and Ghrelin

By now we have all heard of Leptin; that wonderful hormone that tells us when we’re full. Leptin is yet another reason not to fear adipose tissue or fat. We can fear overeating but fat keeps us warm, tells us when to stop eating (if we listen), stores energy, provides protection for our internal organs, contributes to our body’s structural frame, and helps defend against invading organisms.

At any given time, we have 30 known hormones circulating through our bodies. Each hormone preforms several tasks and is responsible for signaling other hormones and organs. Without these vital chemical messengers we would cease to exist. Next time you think of fat, consider all the work fat does for you 24 hours each and every day.

Fat tissue secrets Leptin which, among other functions, aids in controlling hunger by signaling our hypothalamus, one of the body’s important control centers. Included in the many causes of obesity is Leptin resistance. This resistance to such an important hormone can be caused by genetic disorders, endocrine suppression, and poor dietary health. Researchers have discovered that levels of Leptin in obese persons are higher than that of someone with a normal body weight, but their sensory receptors have malfunctioned. There is much speculation that a diet rich in processed sugars and white flour can cause resistance to Leptin resulting in an overactive appetite. Once again, a healthy diet prevails.

Leptin’s nemesis is Ghrelin, a hormone secreted by the lining of the stomach. Ghrelin levels increase in the body to signal that we are hungry then decrease to lessen appetite. As with all hormones, Ghrelin has multiple functions but telling us we need to eat seems to be the most obvious. Like Leptin, the normal production of Ghrelin can be interrupted or accelerated by extenuating circumstances. One example is lack of sleep. Scientists uncovered a direct correlation between obesity and sleeplessness. It seems sleep deprivation causes increased Ghrelin production even if the body has enough energy stores. The moral of this story… a nutritious diet and adequate sleep can help you stay slim and healthy.