Previous studies have investigated obesity and mortality in middle-aged populations, gleaning insights as to the detrimental effects of obesity in middle age. Esther Zimmermann, from Copenhagen University Hospital (Denmark), and colleagues completed a study investigating how obesity at age 20 years affects obesity throughout adult life, as well as the lifelong effect of excess weight on death risk. The team tracked more than 5,000 military conscripts starting at the age of 20 until up to the age of 80. They found that at any given age, an obese man was twice as likely to die as a man who was not obese and that obesity at age 20 years had a constant effect on death up to 60 years later. The researchers also found that the chance of dying early increased by 10% for each BMI point above the threshold for a healthy weight and that this persisted throughout life, with the obese dying about eight years earlier than the non-obese.