Maintaining independence in later life depends not just on staying physically active, but on addressing interconnected factors that many seniors overlook. The relationship between movement and functional ability becomes significantly weaker when older adults experience nutritional deficits or social isolation, suggesting that exercise alone may be insufficient for preserving autonomy. This accelerometry-based study of 53 community-dwelling adults aged 80 on average revealed that daily walking duration and frequency of walking episodes directly predicted scores on standardized independence measures. However, nutritional risk scores and loneliness ratings emerged as critical moderating factors that either strengthened or undermined these beneficial associations between physical activity and functional capacity. The research employed objective seven-day movement tracking rather than self-reported activity, providing more reliable data on actual behavior patterns including sitting, lying, and upright time distribution. Participants showed relatively high functional status overall, with median scores of 20 out of 21 on daily living assessments, yet substantial variation existed in sleep quality, oral health, and nutritional screening results. This finding challenges the conventional focus on exercise prescription alone for aging adults. The data suggests that nutrition counseling and social connection interventions may be equally important for maintaining independence. For health-conscious older adults, this research underscores the importance of a multifaceted approach to healthy aging. While the sample size limits generalizability, the use of objective activity monitoring strengthens the validity of these associations. The study represents incremental progress in understanding how behavioral health determinants interact, though larger longitudinal studies are needed to establish causal relationships and inform targeted interventions.