Background/Objectives: The aging process is typically marked by a reduction in functional fitness, which heightens the likelihood of falling. Although obesity is established as a determinant of poor mobility, the interplay between excess weight and advanced age is still a topic of research interest. Therefore, this research investigated how age, sex, and Body Mass Index (BMI) interact to influence fall risk among older adults living in the community. Methods: This cross-sectional investigation involved 815 participants (Mage = 70.45 ± 6.10 years), stratified by age (sexagenarians, septuagenarians, octogenarians) and BMI (normal weight, overweight, obesity). Fall risk was assessed using the Timed Up and Go test. A Three-Way ANOVA examined the main and interaction effects. Results: No significant three-way interaction (p = 0.334) or main effect of sex (p = 0.079) was found. However, a significant age x BMI interaction was observed (p = 0.007). In sexagenarians and septuagenarians, obesity was associated with significantly slower fall risk performance compared to normal weight (p < 0.001). Conversely, in octogenarians, this difference was not significant (p = 1.000) with normal-weight individuals. Conclusions: Obesity may be a significant risk factor for falls, especially in adults aged 60 to 79 years. In octogenarians, the protective benefit of normal weight disappears, revealing a “weight paradox” likely driven by sarcopenia. Fall risk assessments and weight management strategies should be tailored to age, focusing on preserving muscle mass in octogenarians.
Rodrigues et al. (2026) studied this question.