Relationship Between Cognitive Performance and Anthropometric Status, Dietary Diversity, and Diet Quality in Older Turkish Adults: A Cross-Sectional Study

Background/Objectives: The increasing prevalence of mild cognitive impairment and dementia among older adults represents a major public health concern. This study aimed to examine the relationships between anthropometric status, dietary diversity, dietary quality, and cognitive performance in older adults. Methods: This study was a cross-sectional study. Anthropometric measurements were performed. The Dietary Diversity Score (DDS), Healthy Eating Index-2020 (HEI-2020), 24 h dietary recall and the Montreal Cognitive Assessment (MoCA) were used. We used hierarchical multiple linear regression analysis. Results: Among 117 older adults, 53.0% screened positive for possible mild cognitive impairment (MCI) based on the MoCA. Participants screening positive for possible MCI had a higher body mass index (BMI) compared to those with normal cognitive performance (32.67 ± 5.78 and 29.54 ± 3.39 kg/m2; p < 0.001) and a higher prevalence of obesity (62.9% and 41.8%; p = 0.027). The final regression model explained 26.0% of the variance in MoCA scores (R2 = 0.260; adjusted R2 = 0.212; p < 0.001). More years of education were associated with higher MoCA scores (B = 0.768, β = 0.363, p < 0.001), while higher BMI was associated with lower MoCA scores (B = −0.301, β = −0.240, p = 0.010). Conclusions: In older adults, higher BMI values were found to be associated with lower MoCA scores in the adjusted model. In this sample, no significant correlation was found between DDS and HEI-2020 scores obtained from a single 24 h food intake record and MoCA scores. Longitudinal studies including repeated nutritional assessments are needed to clarify the direction of these relationships.