Data on 6,500 Danish men showed those who were obese at age 22 had an eightfold increased risk of diabetes, were more than twice as likely to suffer high blood pressure or a heart attack and were up to four times as likely to develop potentially fatal blood clots at age 55 than those with normal weight. Researchers also observed a 20% increase in diabetes risk, a 5% increased risk of heart attack and a 10% higher risk of high blood pressure and blood clots for every additional unit in body mass index.