An international committee of over 50 experts has proposed a new approach for determining excess body fat, moving beyond the traditional reliance on body mass index (BMI). The committee, composed of specialists in nutrition, endocrinology, and public health, published their findings in The Lancet Diabetes & Endocrinology on January 14, 2025. The report challenges the notion that BMI is an accurate or sufficient measure of health as it relates to weight.
BMI, which is based solely on a person’s height and weight, has long been used to classify individuals into weight categories. However, the report highlights that BMI lacks the nuance needed to assess health properly. The committee suggests that a better indicator of a person’s health is the amount of belly fat they carry.
To measure abdominal fat, experts recommend methods such as measuring waist circumference, waist-to-hip ratio, or waist-to-height ratio. Additionally, scans that measure the precise amount of excess belly fat can provide more accurate data than BMI alone.
BMI’s limitations are evident in its inability to distinguish between fat and muscle mass. For example, athletes with high muscle mass might fall into the “obese” category despite having little body fat. Conversely, individuals with a “healthy” BMI might still have harmful visceral fat around their internal organs.
Dr. Robert Kushner, an endocrinologist at Northwestern University and a member of the commission, emphasized that belly fat is particularly dangerous because it causes systemic inflammation, which can lead to metabolic problems such as elevated blood sugar, high blood pressure, and abnormal blood fats. This inflammation can increase the risk of diabetes and heart disease.
While the committee does not propose eliminating BMI entirely, they stress the importance of considering abdominal fat as an additional metric for a more comprehensive understanding of health. Dr. David Cummings, an obesity expert at the University of Washington and another commission member, stated that the goal is to provide a more precise definition of obesity to better target those who need intervention.
The report also suggests that medical professionals adopt two distinct diagnostic categories for obesity: clinical obesity and pre-clinical obesity. Clinical obesity refers to individuals with excess body fat who also exhibit related health problems, such as heart disease or high blood pressure. Pre-clinical obesity applies to those with excess weight but without the chronic conditions commonly associated with obesity.
