Obesity is associated with more than thirty medical conditions and scientific evidence has established a strong relationship with at least fifteen of those conditions. Obesity is associated with the development of osteoarthritis of the hand, hip, back, and knees. Obesity increases the risk of breast cancer in men and women, and it is strongly associated with cancer of the esophagus. Obese women have three to four times the risk of endometrial cancer than women with a lower body-mass index. Obesity increases cardiovascular disease risk because of its effect on blood lipid levels; thus, obesity is a major risk factor for heart attack. Other medical problems may include high blood pressure, diabetes, sleep apnea and other respiratory problems, gallstones, and a decrease in the body’s resistance to harmful organisms. Also, obesity is the most common factor of nonalcoholic steatophepatitis, a major cause of liver disease. In cultures where the ideal of physical attractiveness is to be thin, obese people may also suffer from psychosocial effects of societal disapproval. Obesity has a far-ranging negative effect on health. If obesity were eliminated in the United States, an estimated 300,000 premature deaths could be prevented.