By 2015, 2.3 billion adults will be overweight in the world, with more than 700 million of them obese, according to the World Health Organization. As a result, deaths caused by diabetes will increase more than 50 percent during that time.
Obesity in the U.S. is one of the strongest risk factors for type 2 diabetes in the country. For those who are overweight, though, the risk of developing diabetes is less clear. This is partially because body composition is assessed using body mass index, which has some limitations.
BMI uses height and weight to determine if a person is overweight or obese. In addition to classifying some very muscular men as obese, this calculation fails to take into account where fat is located in the body.
Waist size, measured as the circumference around the waist, is better at identifying abdominal fat than is BMI. According to a new study, it is also a good indicator of the risk of diabetes, especially in overweight men and women.
By following over 340,000 people for up to 17 years, European researchers found that the risk of diabetes increased with larger waistlines. This was true for overweight, obese, and normal-weight people.
This information was particularly useful, however, for overweight people with large waists. After 10 years, seven percent of men with a waist larger than 40 inches developed type 2 diabetes; 4.4 percent of women with a waist larger than 35 inches did.
Doctors already target people who are obese for lifestyle changes. Using waist size and BMI together, though, would enable them to also focus on overweight people at risk of diabetes. Early changes to their diet and physical activity levels could head off type 2 diabetes before it develops.