Leptin, a hormone which occurs naturally in the body, has been found to control people’s fondness for food as well as regulating appetite. Hunger may be a critical influencing factor involved in how much we eat but it is by no means the only factor. Eating is normally a pleasant experience which activates reward centres in the brain and this can overrule any indication from the brain to stop eating as we are no longer hungry.
Research by a team at the University of Cambridge has found that leptin affects emotional responses to food. A group of patients with a rare genetic condition which means that they cannot produce leptin was compared with a group of healthy volunteers. The area of the brain which processes rewards, known as the striatal region, was monitored in both groups of volunteers. It was observed that the group of patients who lacked leptin responded to pictures of food even after they had eaten whereas the group of healthy volunteers only responded if they were hungry. The group of patients with the genetic defect were observed to produce normal brain activity when they were treated with leptin.
Obviously treatment with leptin is not going to be appropriate for overweight people who are overweight for other reasons. For people who are experiencing appetites which are difficult to control, treatment with Reductil or Acomplia may be appropriate.