A Simple Waist Measurement Can Spot Obesity Risks BMI Alone Misses, Study Finds

Measuring waist circumference can reveal obesity-related health risks that body mass index (BMI) alone may miss, according to a new study from Rutgers Health published in JAMA Network Open. The researchers found that waist circumference, used alone or together with BMI, was about as effective as a more complicated new framework that combines several different body measurements.

The study analysed data from 1,900 U.S. adults aged 20 to 59 who took part in the National Health and Nutrition Examination Survey. Researchers compared several obesity-screening methods against a highly accurate method for measuring body fat directly. One method tested was a recently proposed framework that combines BMI, waist circumference, waist-to-height ratio and waist-to-hip ratio. While that framework identified more people with excess body fat, the team found that simpler methods worked nearly as well. Using BMI or waist circumference alone gave a similar balance between correctly identifying obesity and avoiding false-positive diagnoses.

Hip circumference, needed for one of the proposed framework's measurements, is rarely recorded in routine clinical visits, whereas waist circumference is simpler to measure and already appears in some clinical guidelines. "A waist measurement provides much of the information needed and is feasible for clinicians and patients alike," said Aayush Visaria, the study's lead author and a faculty member at the Rutgers Health-RWJBarnabas Health Center for Climate, Health, and Healthcare. He added that BMI used by itself failed to identify a substantial number of people who met body-fat criteria for obesity, adding to longstanding concerns that BMI does not reflect where fat is stored in the body.

Visaria said clothing size can be an early sign of unhealthy body fat even before a formal waist measurement is taken, and that tracking both weight and waist size can help identify risks for diabetes, heart disease, stroke and some cancers earlier. The study was coauthored by Soko Setoguchi, Ethan Halm, Douglas Corsi, Dylon Patel, Keerthana Kesavarapu and Jeffrey Carson, all of Rutgers Health.