Dr. Oh and his team analyzed the health information of 3,678 men and women ages 40 to 96, from the Korean Genome and Epidemiology Study. The researchers measured participants’ weight and body mass index (BMI) two times per year, and considered overweight as a BMI of 25, which aligns with the National Heart, Lung, and Blood Institute’s (NHLBI) definition of overweight in the United States.