Food- and weight-related attitudes were assessed in obese subjects prior to biliopancreatic diversion (BPD) and at 1 and 2 years after BPD, when any preoccupation with dieting and body weight and shape should have been abandoned. A decrease in the number of subjects whose food attitudes suggested some loss of control over food consumption, such as snacking, nibbling, getting hungry and eating in response to non-alimentary stimuli or arousal conditions was observed, confirming the role of dieting in leading to loss of control over food intake. The stable weight loss correlated with changes in the body attitudes and in the overall psychological status. The changes observed in obese persons after BPD suggest that 1) the food-related attitudes are influenced by the preoccupation with food and with dieting; 2) the weight-related attitudes are accounted for more by dissatisfaction with a body shape that is very different from the socially accepted one than by an individual's psychological traits.