Abstract
BACKGROUND: Older adults with Alzheimer's dementia commonly experience feeding difficulties, malnutrition, reduced physical activity, and heightened sarcopenia risk, yet the interrelationships among these factors are not well understood. This study aimed to examine the associations among nutritional status, physical functioning, and dietary adherence in older adults and to assess how these relationships may differ according to the presence of Alzheimer's dementia. METHODS: A total of 145 community-dwelling older adults participated, including 60 individuals with Alzheimer's dementia and 85 without. Nutritional status was assessed using the Nutritional Form for the Elderly (NUFFE), feeding difficulty with the Edinburgh Feeding Evaluation in Dementia (EdFED), dietary adherence with the Mediterranean Diet Adherence Screener (MEDAS), physical fitness with the Physical Fitness and Exercise Activity Levels of Older Adults Scale (PFES), and sarcopenia risk with the SARC-F scale. Group differences were examined using the Mann-Whitney U and chi-square tests. Associations were further analyzed using binary logistic regression and moderated mediation analysis (Model 59). RESULTS: Individuals with Alzheimer's dementia exhibited poorer nutritional status (EdFED: 8.0 vs. 2.0; NUFFE: 10.0 vs. 7.0; both p < 0.001) and lower adherence to the Mediterranean diet (6.0 vs. 7.0; p = 0.050). Physical fitness scores were lower (PFES: 78.0 vs. 73.0; p < 0.001), and sarcopenia risk (SARC-F ≥ 4) was higher in the dementia group (88.3% vs. 64.7%; p = 0.001). Feeding difficulty, nutritional status, and physical function were strongly correlated (r = 0.49-0.73; p < 0.01). Logistic regression showed that higher EdFED (OR = 1.15; p < 0.001) and NUFFE (OR = 1.14; p = 0.002) scores were associated with a higher likelihood of dementia, while greater adherence to the Mediterranean diet was associated with a lower likelihood (OR = 0.82; p = 0.015). Moderated mediation analyses indicated that only the PFES model showed a significant moderated indirect effect (IMM = -0.251, 95% CI -0.407 to -0.110), whereas the NUFFE and MEDAS models did not (IMM = -0.137 and -0.009, CIs including zero). CONCLUSION: Feeding difficulties, malnutrition, reduced physical fitness, and sarcopenia were substantially more common in individuals with Alzheimer's dementia. Physical fitness emerged as the strongest mediator linking feeding difficulties to sarcopenia, highlighting the need for integrated nutritional and functional interventions in cognitively impaired older adults.