Poor nutritional status, low fat-free mass index, reduced muscle strength, slower gait speed, dysphagia, and sarcopenia were associated with functional dependency in older adults, with MNA showing excellent discriminatory ability (AUC=0.894) and FFMI contributing a small suppression effect rather than conventional mediation in the nutritional-functional status association.
Key Findings
Results
The majority of long-term care residents were malnourished or at risk of malnutrition, and over two-thirds were functionally dependent.
Study included 165 adults aged ≥65 years residing in long-term care centers in Istanbul, Türkiye, of whom 51.5% were women
44.2% of participants were malnourished and 32.7% were at risk of malnutrition
70.3% of participants were functionally dependent
Nutritional status was assessed using the Mini Nutritional Assessment (MNA) and functional status using the Barthel Index
Results
Higher MNA scores were associated with significantly lower odds of functional dependency.
OR=0.66, 95% CI: 0.57–0.77 for MNA score and functional dependency
The MNA score showed excellent discriminatory ability for functional dependency with AUC=0.894
Path analysis showed a strong positive direct association between MNA and Barthel Index scores (β=0.882, p<0.001)
These findings should be interpreted as concurrent cross-sectional relationships rather than evidence of mediation or causality
Results
Higher fat-free mass index (FFMI) was associated with lower odds of functional dependency.
OR=0.84, 95% CI: 0.72–0.98 for FFMI and functional dependency
Body composition was measured using multifrequency bioelectrical impedance analysis (InBody S10)
Path analysis revealed a small negative indirect association between MNA and Barthel Index scores through FFMI (β=−0.023, bootstrap 95% CI: −0.053 to −0.002)
The opposing directions of the direct and indirect associations were consistent with a statistical suppression pattern rather than a conventional mediating relationship
Results
Greater handgrip strength and faster gait speed were each associated with lower odds of functional dependency.
Handgrip strength OR=0.73, 95% CI: 0.61–0.88
Gait speed OR=0.64, 95% CI: 0.45–0.91
Both handgrip strength and gait speed were evaluated as part of the multivariable regression analysis
These associations were assessed alongside nutritional status, body composition, dysphagia, and sarcopenia
Results
Dysphagia and sarcopenia were each associated with substantially higher odds of functional dependency.
Dysphagia OR=8.27, 95% CI: 2.23–30.65
Sarcopenia OR=3.90, 95% CI: 1.43–10.63
Dysphagia showed the strongest association with functional dependency among all variables examined
Both dysphagia and sarcopenia were evaluated alongside nutritional status, FFMI, handgrip strength, and gait speed in multivariable regression
Results
The indirect association of nutritional status with functional dependency through FFMI represented a statistical suppression pattern rather than conventional mediation.
The indirect path coefficient was β=−0.023 (bootstrap 95% CI: −0.053 to −0.002), which was small and opposite in direction to the strong direct association (β=0.882)
Observed-variable path analysis was used to evaluate whether FFMI statistically contributed to the indirect association between nutritional and functional status
The authors explicitly state findings should be interpreted as 'concurrent cross-sectional relationships rather than evidence of mediation, temporal ordering, or causality'
Longitudinal studies are needed to clarify temporal and clinical significance of these relationships
What This Means
This research suggests that among older adults living in long-term care facilities, poor nutritional status, low muscle mass (measured as fat-free mass index), weak grip strength, slow walking speed, difficulty swallowing (dysphagia), and sarcopenia (muscle wasting condition) are all linked to greater difficulty performing everyday activities independently. The study found that nearly half of participants were malnourished and over two-thirds were functionally dependent, highlighting the high burden of these conditions in this population. The Mini Nutritional Assessment tool proved highly accurate at identifying who was functionally dependent, with an AUC of 0.894, suggesting it could be a useful screening tool in care settings.
The study also used a statistical technique called path analysis to explore whether low muscle mass explains part of the relationship between poor nutrition and functional decline. While it found that muscle mass did play a small statistical role, the pattern was unusual — the indirect effect through muscle mass actually pointed in the opposite direction from the main direct relationship. The researchers caution that this reflects a statistical phenomenon called 'suppression' rather than a straightforward chain of cause and effect, and that the findings cannot be used to conclude that improving nutrition leads to better muscle mass which then leads to better function.
This research suggests that nutritional status is a strong marker of functional ability in older adults in care homes, and that dysphagia and sarcopenia are particularly concerning risk factors for losing independence. However, because this was a cross-sectional study — meaning everyone was measured at one point in time — it cannot determine whether poor nutrition causes functional decline or vice versa. The authors call for longitudinal studies that follow people over time to better understand how these factors interact and whether targeting nutrition and muscle mass could help preserve independence in older adults.
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Alataş H, Arslan N, Güneş E, Kurt H, Bentli S. (2026). Nutritional Status, Fat-Free Mass Index, and Functional Dependency in Older Adults: A Cross-Sectional Path Analysis.. Clinical interventions in aging. https://doi.org/10.2147/CIA.S643163