 The objective of the project is the constitution of a population-based cohort of 500 persons with severe or morbid obesity BMI over 35 kgm2 with annual follow-up for 10 years. It aims to improve the physiopathological, epidemiological and prognostic knowledge of obesity and its consequences. Clinical data, biological material, exams and questionaires will be collected and stored, allowing the realisation of research works, initiated by research teams from our hospital or from other settings. 