Researchers find waist circumference rivals complex obesity health risk assessments

Researchers argue that waist circumference may be one of the simplest and most effective ways to detect obesity-related health risks. They found that the method performed as well as multiple body measurements for obesity, when carried out alone or in combination with body mass index (BMI) measurements. 

This quick and simple measurement tool could be used by clinicians to identify associated health risks with potentially unhealthy amounts of body fat.

“Pay attention to the need to loosen your belt or get bigger pants,” says lead study author Aayush Visaria, a faculty member of the Rutgers Health-RWJBarnabas Health Center for Climate, Health, and Healthcare, New Jersey, US. She is also an instructor in the Department of Medicine at Rutgers Robert Wood Johnson Medical School. 

“Although clothing size isn’t the same as a proper waist circumference measurement, it can be an early sign of unhealthy amounts of body fat. Measuring your waist, along with your weight, can help identify health risks earlier and provide an opportunity to reduce your risk of diabetes, heart disease, stroke, and some cancers.”

The researchers argue that their findings may be useful in future obesity screening recommendations and for a broader use of waist circumference measurements in routine health care. 

Simple approach, more accuracy

Published in Jama Network, the research letter includes data from 1,900 US adults aged 20 to 59 who participated in the National Health and Nutrition Examination Survey.

The research team compared various approaches to diagnosing obesity. They examined a recently proposed framework from a group of independent experts — the Lancet Commission’s 2025 clinical obesity diagnostic framework — blending BMI, waist circumference, waist-to-height ratio, and waist-to-hip ratio. 

Waist circumference alone performed nearly as well as when in combination with BMI.They found that using simpler approaches resulted in similar accuracy than more complicated tools.

Waist circumference measurements alone performed nearly as well as when used in combination with BMI. When using BMI as a measurement by itself, the team found it missed a “substantial number of people” who meet the body fat criteria to be classified as obese. 

This sparks concerns that BMI is not a reliable measurement tool for obesity as it fails to capture differences in body fat distribution and composition.

When looking at BMI, obesity researchers previously suggested it is possible to be “fat but fit,” based on a study of tens of thousands of Danish participants. The study found that overweight participants — and some with obesity — did not have a higher mortality likelihood during the five years of follow-up compared to those at the top end of the normal weight range.

Additionally, the proposed framework requires hip circumstance as a measurement, but the researchers note that this measurement is rarely collected routinely in clinical practice. They note that waist circumference is increasingly gaining recognition in clinical guidelines while being easy to obtain in primary care settings. 

“Our findings show that you don’t necessarily need multiple complex measurements to identify obesity-related health risks,” concludes Visaria. “A waist measurement provides much of the information needed and is feasible for clinicians and patients alike.”