Nutrition, physical function influence health outcomes in older adults

Nutritional status and physical function show independent and interactive relationships with health outcomes among older adults, suggests a Singapore study.

“Although both factors are independently associated with various aspects of health, their relationship with health-related quality of life (HRQoL) appears more complex, involving potential mediation effects and interaction effects, respectively,” the researchers said.

Community-dwelling older adults aged ≥60 years (n=699) were identified from the Population Health Index Survey and followed annually for 3 years. 

The research team assessed nutritional status using the Mini Nutritional Assessment and measured physical function using the Late-Life Function and Disability Instrument. The independent and interaction effects of nutritional status and physical function on health outcomes (ie, frailty, depression, loneliness, HRQoL, self-reported health) were assessed using mixed-effect models, adjusted for covariates.

Undernourished individuals were more likely to have frailty (odds ratio [OR], 8.94, 95 percent confidence interval [CI], 4.48–17.87), depression (OR, 14.94, 95 percent CI, 7.63–29.23), and loneliness (OR, 5.13, 95 percent CI, 2.77–9.53), lower HRQoL (β, –0.10, 95 percent CI, –0.13 to –0.07), and self-reported health (β, –8.27, 95 percent CI, –10.81 to –5.73) than their well-nourished counterparts. [Am J Clin Nutr 2025;122:811-819]

Similarly, older adults with lower physical function tended to have poorer health outcomes. Notably, the inclusion of both nutritional status and physical function in the model attenuated the associations for nutritional status, according to the researchers.

“Although their interaction term was not associated with most health outcomes, a significant interaction was found for HRQoL, where the negative impact of undernutrition on EQ-5D scores was greater among those with impaired physical function [β, –0.12, 95 percent CI, –0.17 to –0.07),” they added.

Pathways

The lack of a significant interaction effects on health outcomes, except HRQoL, is indicative of the influence of both nutritional status and physical function on physical health, mental health, social health, and self-reported health through independent pathways, according to the researchers.

“Although the exact mechanisms and distinct pathways through which nutritional status and physical function influence various health domains remain unclear, this finding additionally underscores the need for comprehensive interventions that improve both nutritional status and physical function, rather than focusing on either one in isolation,” they added. 

Furthermore, this study is underpowered to detect interaction effects, given its small sample size, since “such effects are generally more difficult to identify than main effects in observational data and typically require larger samples to achieve adequate statistical power,” the researchers said. [Psychol Bull 1993;114:376-390; J Appl Psychol 2005;90:94-107]

"Future studies with larger sample cohorts or pooled datasets are warranted to more conclusively evaluate potential interaction effects,” they added. 

Implications

The current study has important implications for policy and clinical practice. First, both nutritional status and physical function are vital in promoting health and well-being among older adults. Thus, it is necessary to develop interventions that target both nutrition and physical function while considering the “synergistic effects of the two,” according to the researchers.

Second, the findings suggest the importance of early nutritional intervention to prevent functional decline and subsequent frailty in this population.

"In the context of ageing well, it is essential to recognize the importance of individualized nutritional assessments and interventions,” the researchers said. “Tailoring dietary recommendations to meet the specific needs and preferences of older adults can significantly enhance adherence to healthy eating patterns and improve overall nutritional status.”