The case report of an obese patient deals with his background, history of life and its correlation to obesity. The causes, circumstances and habits of eating are almost a perfect expression of the traditional theories of obesity. This case report emphasizes the correlation between the psychiatric theory that divides the obese people into adult and juvenile types and the histological findings that obesity can be divided into hyperplastic and hypertrophic types according to the quality and quantity of the fat cells. In fact these two theories may be manifestations of the basic, yet unknown cause of obesity. A doubt to the classical theories is cast by the operation of jejunoileostomy which changes many personality characteristics which were considered primary in obesity.