Obesity is a major risk factor for several chronic diseases, but the burden associated with it also extends to psychosocial areas and to perceived health status. In 1999 an observational study on health-related quality of life in obesity was planned. The study was entirely web-based. Case Report Forms and the individual items of 7 self-administered questionnaires were directly implemented on a general database via an extranet system from 25 Italian centers. By December 2001, after enrolment had stopped, the database included anthropometric, socioeconomic and clinical data of 1944 patients (78% females). Weight-cycling was reported in over 80 % of cases, overeating in 60-65 %, structured physical activity in only 13-15%. Several chronic illn...