High Body Fat, Not BMI, Linked to Increased Risk of Death and Heart Disease: Study Finds

The results were striking: Adults with high body fat (defined as ≥27% in men and ≥44% in women) were 1.78 times more likely to die from any cause and 3.62 times more likely to die from heart disease compared to those with a healthy fat percentage. In contrast, individuals with a BMI in the overweight or obese range (≥25 kg/m²) did not show a significantly increased risk of death from any cause.

Additionally, a high waist circumference (over 40 inches in men and 35 inches in women) was associated with a 1.59-fold increased risk of all-cause mortality and a 4.01-fold higher risk of death from heart disease.

These findings support a reevaluation of how body composition is assessed in clinical care. “New bioelectrical impedance devices could make it feasible to move beyond BMI in routine health assessments,” the researchers noted. As obesity-related illnesses continue to rise, accurate screening tools could help identify at-risk individuals earlier and guide better preventive strategies.

Reference: Body Mass Index vs Body Fat Percentage as a Predictor of Mortality in Adults Aged 20-49 Years

Arch G. Mainous, Lu Yin, Velyn Wu, Pooja Sharma, Breana M. Jenkins, Aaron A. Saguil, Danielle S. Nelson, Frank A. Orlando

The Annals of Family Medicine Jul 2025, 23 (4) 337-343; DOI: 10.1370/afm.240330