A comparative study on nutritional status and diet-related subjective perceptions according to free meal service utilization among older adults living alone in Korea: a cross-sectional study

OBJECTIVES: To assess whether the use of free meal services is associated with diet quality among older adults living alone in Incheon, Korea, by comparing the Nutrition Quotient for the Elderly (NQ-E), index of nutritional quality (INQ), and mean adequacy ratio (MAR). METHODS: A cross-sectional survey was conducted from March 5 to April 24, 2025 using one-to-one interviews and partially self-administered questionnaires. After excluding cases with missing responses or energy intake of < 500 kcal/day, 119 participants were analyzed (56 men and 63 women). A single 24-hour recall was used to calculate INQ and MAR. NQ-E was evaluated using total and subdomain scores. Group comparisons and sex-stratified multiple linear regression analyses were performed. RESULTS: Diet-quality indicators were higher among service users than among non-users. INQ for thiamin and riboflavin was significantly higher in men than in women. Meanwhile, INQ for zinc, vitamin A, riboflavin, and folate was higher in women than in men. In both sexes, MAR was higher among users than among non-users (men: 0.8 ± 0.2 vs. 0.6 ± 0.2; women: 0.7 ± 0.2 vs. 0.5 ± 0.2; P < 0.001 for all). Differences in NQ-E total scores were small. Among women, the practice subdomain score was higher in users than in non-users (66.0 ± 16.4 vs. 55.2 ± 15.5; P = 0.016), and the proportion in upper grades was greater (P = 0.030). Regression analysis showed that service use was negatively associated with NQ-E in men (P = 0.007) and positively associated with MAR in women (P = 0.010). CONCLUSION: Use of free meal services was associated with improved diet quality, as reflected by MAR and INQ for specific nutrients, and with higher NQ-E practice scores observed in women than in men. Policies should prioritize food-insecure groups and support sustained participation.