Body Fat Assessment Outperforms BMI in Predicting Health Risks, Study Finds
A recent study conducted by the University of Florida has cast doubt on the effectiveness of Body Mass Index (BMI) as a reliable health measure, instead highlighting the superiority of body fat assessment in predicting mortality and heart disease risk. Published in the Annals of Family Medicine, the study indicates that BMI, while widely used to assess obesity, is ‘deeply flawed’ in terms of predicting mortality.
In the study, researchers used bioelectrical impedance analysis (BIA) to measure participants’ body fat levels over a 15-year period. The findings revealed that individuals with high body fat were 78% more likely to die than those with healthy body fat levels, and they were more than three times as likely to die from heart disease, according to the researchers. While BMI has been the international standard for obesity measurement since the 1980s, the study questions its validity, noting that it cannot differentiate between muscle and fat mass.
The study, which included data from 4,252 people in the U.S., argues that BMI should not be relied upon as a ‘vital sign’ of health. Dr. Frank Orlando, the senior author of the study, emphasized that BMI is “entirely unreliable” in predicting death risk over a 15-year period. He acknowledged the limitations of BMI, particularly in its inability to accurately assess body composition for everyone, calling for a shift toward more accurate and accessible methods.
While alternative methods like DEXA scans offer greater accuracy, they are costly and not widely available. The researchers suggest that bioelectrical impedance analysis, though less precise than DEXA, provides a more practical option for routine use. Dr. Stephen Vogel, a family medicine physician, supported the findings, stating that BMI should be replaced with a more nuanced, cost-effective method. He emphasized that the study strengthens the push for updated standards in health assessments, which could improve patient outcomes and public health initiatives.
Despite these findings, the study acknowledges several limitations, including the lack of data on determining optimal body fat thresholds and the age range of participants, which was constrained by the data source. The researchers hope that future studies will expand this comparison to older adults and other conditions, potentially leading to a more comprehensive understanding of body fat as a health risk factor.
The researchers are hopeful that once standards are validated, measuring body fat percentage with bioelectrical impedance analysis could become standard of care. They added, “These data will drive better discussions in the doctor’s office, as well as public health initiatives with the goal of improving the health of all.”