To investigate the proteomic features in lean subjects with NAFLD, and to identify possible plasma proteins that provide potential application for diagnosing of NAFLD in lean individuals. Participants with or without NAFLD were divided into an overweight NAFLD group, an overweight control group, a lean NAFLD group, and a lean control group according to body mass index. Samples of 20 subjects in each group were used for plasma proteomic profiling.