Adherence to the EAT-Lancet reference diet and risk of type 2 diabetes, metabolic dysfunction-associated steatotic liver disease, and their co-occurrence.

: The EAT-Lancet Commission proposed a healthy dietary pattern to prevent diet-related diseases while promoting planetary sustainability, but little is known regarding its associations with type 2 diabetes (T2D) and metabolic dysfunction-associated steatotic liver disease (MASLD), both of which are highly prevalent and frequently co-exist. We aimed to assess association of this diet with risk of T2D, MASLD, and their co-occurrence. : This study included 170 811 UK Biobank participants (prospective design) and 212 Chinese biopsy-proven MASLD patients (cross-sectional design). Adherence to the EAT-Lancet reference diet was quantified using three different diet indices. Cox and logistic models were applied to estimate the corresponding effect size. : During follow-up in the UK Biobank, we identified 4240 T2D cases, 1164 MASLD cases, and 215 co-incidents of the two diseases. The multivariable hazard ratios (95% confidence intervals) per standard deviation (SD) increase in the Planetary Health Diet Index were 0.85 (0.82, 0.87) for T2D, 0.80 (0.75, 0.85) for MASLD, and 0.84 (0.74, 0.97) for the co-occurrence of the two conditions. The associations were attenuated after additional adjustment for body mass index. In addition, 96 (45.3%) patients with biopsy-proven MASLD had prevalent T2D; adjusted odds ratios (95% confidence intervals) per SD of T2D were 0.72 (0.51, 1.00) for the Planetary Health Diet Index. Similar association patterns were observed in the other two indices. : Greater adherence to the EAT-Lancet reference diet was not only associated with lower risks of incident T2D, MASLD, and the co-occurrence of the two conditions in the general adult population but was also associated with lower prevalence of T2D among biopsy-proven MASLD patients.