|Obesity is an epidemic Western world problem. Although it is clear that being obese is unhealthy, no effective ways for long term weight reduction have been identified yet. The other side of the picture shows a fraction of people in Western societies that deliberately starve themselves extremely successful (Anorexia Nervosa (AN) sufferers). In the present project fMRI is used to test the prediction that obese people show exaggerated food-reward processing, while self-starvers (AN) show decreased food-reward processing in the brain. Secondly, by manipulating the magnitude of food reward processing, it is tested whether reduced food-reward processing predicts weight loss whereas increased food-reward processing predicts weight gain.