Study finds BMI ‘deeply flawed’ for predicting death risk versus body fat

Body mass index (BMI) has long been used as a standard measurement to determine whether a person’s weight is within a healthy range for their height. However, a recent study conducted by the University of Florida has revealed that BMI may not be the most accurate predictor of mortality risk. The study found that BMI is “deeply flawed” when it comes to predicting death risk, and that one’s level of body fat is a far more accurate indicator.

The researchers utilized bioelectrical impedance analysis (BIA) to measure participants’ body fat levels. Over a 15-year period, individuals with high body fat were found to be 78% more likely to die than those with healthy body fat levels. Additionally, they were more than three times as likely to die from heart disease. In contrast, BMI was deemed “entirely unreliable” in predicting the risk of death from any cause over a 15-year period.

Senior author of the study, Dr. Frank Orlando, emphasized that BMI should not be considered a vital sign of health. While BMI is easy to calculate by dividing weight by height squared, it fails to distinguish between muscle and fat mass. This limitation can lead to inaccuracies, such as individuals with high muscle mass being classified as obese based on BMI alone.

Dr. Stephen Vogel, a family medicine physician, highlighted the need for alternative methods of measuring body fat that are both accurate and accessible. While methods like DEXA scans may provide more precise results, they are not practical for routine use in a doctor’s office. The goal is to establish new standards that offer better insight into an individual’s physical health.

The study’s findings underscore the importance of reevaluating how body fat is measured and its impact on overall health. By shifting the focus from BMI to more accurate indicators like body fat percentage, healthcare providers can make more informed decisions and tailor treatment plans to better support patients’ well-being.

Moving forward, the researchers hope to establish standardized thresholds for body fat percentage and implement bioelectrical impedance analysis as a standard of care. By improving the measurement of body fat, healthcare professionals can enhance discussions with patients and develop more effective public health initiatives aimed at improving overall health outcomes.