Is there a BMI Threshold Value Associated with a Lower Physical Capacity in Well-Functioning Older Adults? The Quebec Longitudinal Study

Objective: Identify a body mass index (BMI) threshold above which physical capacity would be significantly affected. Methods: This study included 904 physically independent older individuals aged between 67 and 84 years old. Measures were: BMI, physical capacity score (PCS) computed according to five lower extremity physical tests, sum of reported chronic conditions and physical activity level. Results: When subjects were divided in 10 BMI groups, no clear threshold was identified in men since the PCS was only significantly decreased in the heaviest group, which correspond to a BMI of >34.5 kg/m2. In women, a BMI of 30.5 kg/m2 was identified as the threshold above which the PCS was significantly decreased compared with the reference group. Discussion: Although no clear BMI threshold was identify in older men, a BMI of 30.5 kg/m2 in women was associated with a significantly lower physical capacity.