Abstract Background To investigate the association between the risk of lung cancer and short‐term body mass index (BMI) changes in male never‐smokers of a large population‐based prospective study. Methods A total of 37,085 male never‐smokers from Kailuan cohort with at least ≥2 BMI measurements were recruited in the present study. The BMI change in the follow‐up was calculated as the annual percent change between BMI at last examination and that at baseline, and categorized into five groups: stable (−0.1 to