Adherence to the EAT-Lancet reference diet and risk of diabetes mellitus: a systematic review and dose-response meta-analysis of prospective studies

Limited observational studies have investigated the association between the EAT-Lancet reference diet and risk of diabetes mellitus.Therefore, this study conducted a systematic review and dose-response meta-analysis to determine the association between adherence to the EAT-Lancet reference diet and diabetes mellitus risk. A comprehensive literature search of authentic electronic resources including PubMed, ISI Web of Science, Embase and China National Knowledge Infrastructure (CNKI) was carried out to identify the relevant articles published up to December 2025. Given the significant heterogeneity among studies, we used a random-effects model (DerSimonnian and Laird method) for the meta- analysis. Furthermore, we also provided a prediction interval, which was helpful for assessing whether the variation among studies was clinically significant. In total, 10 articles involving 722,078 participants and 72,201 cases were included in the final analysis. When comparing the highest with the lowest categories of EAT-Lancet reference diet score, the pooled RRs for diabetes mellitus was 0.76 (95% CI: 0.68–0.95, prediction interval:0.50–1.16 P < 0.001). Each standard deviation (SD) increment in the EAT-Lancet reference reference diet score was associated with an 8% lower risk of diabetes mellitus (RR = 0.92; 95%CI: 0.89–0.95, prediction interval:0.81–1.04, P < 0.001; I 2 = 93.9%, P < 0.001).Dose-response analysis demonstrated a linear trend association between adherence to the EAT-Lancet reference diet and diabetes mellitus risk (RR = 0.973; 95%CI: 0.946–1.001, P nonlinearity =0.549, P dose−response =0.061). Subgroup analyses showed a significant inverse association between adherence to the EAT-Lancet reference diet and diabetes mellitus in participants with mean age < 50 years (RR = 0.64, 95%CI: 0.41-1.00, prediction interval: 0.08–5.44, P = 0.05), with significant heterogeneity ( P < 0.001; I 2 = 94.2%). Additionally, the results showed the association between adherence to the EAT-Lancet reference diet and a lower risk of diabetes mellitus in the subgroup with outcome being diabetes mellitus (RR = 0.56, 95%CI: 0.45–0.69). Our findings demonstrate that higher adherence to the EAT-Lancet reference diet is associated with a reduced risk of diabetes mellitus. Promoting a sustainable, plant-based diet should be an effective strategy for addressing the global public health challenge of diabetes mellitus. However, the significant heterogeneity was observed across studies, further large prospective studies in ethnically diverse populations are needed to confirm these findings.