Intermittent Fasting and Risk of Diabetic Retinopathy: Retrospective Data from the National Health and Nutrition Examination Survey.

<b>Background/Objectives:</b> Diabetic retinopathy (DR) is the most common microvascular complication of diabetes and a significant cause of severe visual impairment. Intermittent fasting (IF) has demonstrated metabolic benefits. We investigated the association between IF and DR risk in individuals with prediabetes and diabetes. <b>Methods:</b> This retrospective cohort study included participants of the Korean National Health and Nutrition Examination Survey 2017-2018 aged ≥40 years who were diagnosed with diabetes or prediabetes who had fundus photography and dietary pattern data. Participants were allocated to the IF (fasting for 24 h or skipping breakfast or dinner) and regular diet groups. Demographic, dietary pattern and clinical data, including DR prevalence, were compared between the groups. Multiple logistic regression assessed the association between IF and DR risk. <b>Results:</b> Of 922 participants, 831 followed a regular diet while 91 practiced IF. The participants in the IF group were significantly younger and more obese, had higher fat intake, and showed a lower prevalence of DR than those in the regular diet group (8.8% vs. 20.6%, <i>p</i> = 0.010). After adjusting for multiple covariates, including demographics, comorbidities, health behaviors, biochemical parameters, and nutritional intake profiles, IF was associated with a 70% reduced risk of DR (OR 0.30, 95% CI 0.12-0.65, <i>p</i> = 0.005). This association did not differ across subgroups (all <i>p</i> for interaction > 0.05). <b>Conclusions:</b> IF was significantly associated with reduced DR risk in this study. Further studies are needed to validate the effectiveness of IF as a dietary intervention for DR.