1) The study investigated how BMI affects sedentary behavior and physical activity in older adults. It found that overweight-obese older adults had lower total energy expenditure, stepping time, and fragmentation of sedentary periods than normal weight older adults, even after accounting for age differences. 2) Fragmentation, which measures breaks in sedentary time, was more sensitive than total sedentary time in detecting differences. Total sitting/lying time and standing time did not differ between the groups. 3) The results suggest that BMI is a significant predictor of physical activity levels and sedentary behavior patterns in older adults when age is considered. However, the cross-sectional design means causation cannot be determined.