BMI Limitations Highlighted as Experts Recommend Broader Health Metrics

Recent scientific reports and studies have examined the limitations of Body Mass Index (BMI) as a health assessment tool, prompting recommendations for additional measurement methods to improve accuracy in evaluating obesity-related health risks.

BMI does not account for differences between fat and muscle mass or indicate where fat is distributed in the body. As a result, some individuals may be misclassified regarding their health status, with metabolically healthy people sometimes labeled overweight or obese, while others with normal BMI may experience serious health conditions.

An international panel of over 50 experts published recommendations in January 2025 advocating for the use of waist circumference, waist-to-hip ratio, and waist-to-height ratio alongside BMI. The panel also introduced two diagnostic categories: "clinical obesity," defined as excess fat with health complications, and "pre-clinical obesity," where excess fat exists without current health issues.

Supporting these recommendations, a global commission endorsed by more than 75 medical organizations called for redefining obesity criteria to include waist-based measurements and clinical indicators, moving beyond sole reliance on BMI.

What the numbers show

• Body fat percentage measured by bioelectrical impedance analysis predicted 15-year mortality more accurately than BMI
• High body fat was linked to a 78% higher risk of death and 3.6 times greater heart disease mortality
• Waist circumference above 40 inches for men and 35 inches for women was associated with a 59% higher risk of death
• A study of nearly 388,000 participants found waist-to-hip ratio was a stronger predictor of mortality than BMI

Research published in 2025 found that body fat percentage, measured using bioelectrical impedance analysis, provided a stronger prediction of all-cause and heart-disease mortality over 15 years than BMI. In this study, individuals with higher body fat had notably increased risks of death and heart disease, while BMI did not show a significant association with mortality outcomes.

Waist circumference and waist-to-hip ratio have demonstrated stronger links with metabolic syndrome and cardiovascular events than BMI. For example, waist-to-hip ratio better reflects abdominal fat, which is more closely associated with chronic health conditions, and is linked to cardiovascular events in certain patient groups where BMI is not.

Alternative indices have been developed to address BMI's limitations. The Body Roundness Index (BRI) uses waist and hip measurements relative to height and may predict mortality and visceral fat more effectively than BMI. Other measures, such as the Body Adiposity Index, Relative Fat Mass, and sagittal abdominal diameter, aim to estimate body fat and disease risk with greater precision.

Waist circumference has also been shown to correlate more strongly with metabolic syndrome indicators than either BMI or percentage body fat. Sagittal abdominal diameter, which measures abdominal depth, is recognized as a strong predictor of coronary disease and insulin resistance, independent of BMI. Relative Fat Mass, which uses waist and height, may offer improved accuracy for estimating body fat, though further validation is ongoing.

* This article is based on publicly available information at the time of writing.