Body Fat More Dangerous Than Body Size?
Researchers found that fat levels are a more accurate indicator of early death than currently used BMI measurement.
HealthDay News — Body mass index (BMI) may not accurately reflect a person's body composition, or be a good indicator of health, according to research published online March 8 in the Annals of Internal Medicine.
William Leslie, MD, a professor of medicine and radiology at the University of Manitoba in Winnipeg, Canada, and colleagues evaluated data on 54,420 adults, mostly in their 60s, who'd undergone dual-energy X-ray absorptiometry scans.
The researchers found that men and women with the greatest amounts of body fat were more likely to die over the next 4 to 7 years. Men in the top 20% had at least 36% body fat. And those with highest body fat were up to 59% more likely to die during the study period, versus men whose body fat was in the 28% to 32% range – which was about average for the group. The difference was smaller among women. Still, those with the highest percentage of body fat – about 39% fat or higher – were 19% more likely to die during the study period, compared with women in the 30% to 34% range (about average for the group).
In contrast, people with a BMI high enough to classify them as obese didn't show an increased death risk. And they were actually less likely to die than men and women with the lowest BMIs – lower than 24 or 25 kg/m². In these older adults, Leslie told HealthDay, a lower BMI may reflect waning muscle mass or frailty.
- Padwal R, Leslie WD, Lix LM, et al. Relationship Among Body Fat Percentage, Body Mass Index, and All-Cause Mortality: A Cohort Study. Ann Intern Med. 2016; doi: 10.7326/M15-1181