The research was based on eight years of data on 552,953 middle-aged adults who were obese and intentionally lost weight (meaning their weight loss did not occur because of an illness). Besides the diabetes effect, losing 13 percent of their weight also made people 25 percent less likely to develop high blood pressure or sleep apnea, and it correlated to a 22 percent risk reduction for high cholesterol and a 20 percent lower risk for osteoarthritis.
Obesity, defined as excessive fat accumulation that presents a risk to health, is often determined by a person’s body mass index (BMI), a calculation of body fatness based on weight and height. The simplest way to figure your BMI is to plug your height and weight into an online calculator. A BMI of 30 or above is considered obese. Treatment for obesity usually starts with a modest weight-loss goal of 5 to 10 percent (10 to 20 pounds for someone weighing 200) and includes a change in eating habits and an increase in physical activity.