• Department of Gastrointestinal Surgery, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China.
• Department of Clinical Nutrition, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China.

Previous research has shown that adhering to the Eat-Lancet diet (ELD) is associated with a lower risk of chronic diseases and mortality. However, the associations between ELD and lung cancer incidence and mortality are unclear. To address this gap, we conducted a prospective cohort study involving 101,755 adults from the Prostate, Lung, Colorectal, and Ovarian (PLCO) trial in the USA. The ELD score was utilized to assess compliance with the ELD, with higher scores indicating greater compliance. We employed Cox regression analyses to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) of ELD score with the incidence and mortality of lung cancer and its subtypes. In addition, sensitivity analyses were performed to ensure the robustness of our findings. In total, 1706 cases of lung cancer and 1217 lung cancer-associated deaths were recorded during the study period. Our analysis revealed that higher ELD scores were significantly associated with a reduced incidence (HR_{Quartile 4} vs. _{Quartile 1} : 0.73; 95% CI: 0.60, 0.89; p_trend  = 0.001) and mortality (HR_{Quartile 4 vs. Quartile 1} : 0.74; 95% CI: 0.59, 0.93; p_trend  = 0.005) of lung cancer in a dose-response manner (all p_nonlinearity  > 0.05). The reliability of these results was supported by sensitivity analyses. Notably, these associations were primarily observed in non-small-cell lung cancer. In conclusion, our findings suggest that adherence to the ELD may be associated with a reduced risk of lung cancer incidence and mortality.