The new definition of obesity, which has been endorsed by 76 organizations, including the American Heart Association, could increase the number of Americans classified as obese from 40% to about 70%[1][2]. A study published in JAMA Network Open analyzed data from more than 300,000 Americans and found that the prevalence of obesity increased to 68.6% using the new definition versus 42.9% using the traditional BMI-based definition[5]. In addition to BMI, the new definition also includes measurements of body fat distribution such as waist circumference, waist-to-height ratio, and waist-to-hip ratio[3]. A person is considered obese if they have a high BMI plus at least one elevated anthropometric measurement, or a normal BMI with two elevated measurements[1]. A study showed that nearly 80% of adults over the age of 70 would be classified as obese under the new definition[2]. The researchers stressed that fat distribution is important because even people with a normal BMI, but with accumulated fat in the waist area, have increased health risks[1]. Newly enrolled individuals had a higher risk of adverse health outcomes[5].