Health literacy and nutritional self-efficacy in older adults: the chain- mediating role of perceived social support and positive mental health

Objectives To explore the impact of health literacy on nutritional self-efficacy in older adults and the chain-mediated effects of perceived social support and positive mental health between the two. Methods A total of 265 older adults who met the inclusion criteria in five communities in Zhengzhou City, Henan Province, from July to December 2024 were selected as survey respondents. Questionnaires were administered using the General Information Questionnaire, the short-form Mandarin Health Literacy Scale (s-MHLS), the Nutritional Self-Efficacy Questionnaire Chinese version (NSEQ), the Perceived Social Support Scale (PSSS), and the Positive Mental Health Scale Chinese version (PMHS). Spearman correlation analysis was used to explore the correlation between the variables, AMOS 24.0 software was used to construct the chain mediation model, and the Bootstrap method was used to test the chain mediation model. Results The nutritional self-efficacy score of older adults was (100.28 ± 18.59), and there was a correlation between health literacy, nutritional self-efficacy, perceived social support, and positive mental health ( P  < 0.001). The mediation model showed that the direct effect of health literacy on nutritional self-efficacy was significant in older adults, and health literacy also indirectly affected nutritional self-efficacy through perceived social support ( β  = 0.136, P  < 0.001) and positive mental health ( β  = 0.077, P  < 0.001). Perceived social support and positive mental health acted as chain mediators between health literacy and nutritional self-efficacy ( β  = 0.051, P  < 0.001), with the total indirect effect accounting for 34.73% of the total effect. Conclusion Nutritional self-efficacy among older adults is at an intermediate level. Perceived social support and positive mental health play a mediating role between health literacy and nutritional self-efficacy in older adults. Healthcare professionals and related personnel should pay attention to educating the elderly on health literacy, popularizing knowledge of diseases, and improving their nutritional self-efficacy by enhancing their ability to appreciate social support and maintain positive mental health.