In two samples (N = 247, N = 291), we examined the link between beliefs and messages about the changeable (incremental theory) vs. fixed (entity theory) nature of weight, attributions for weight, and body shame. We recruited participants using online sampling, employing a correlational design in Study 1 and an experimental design in Study 2. Across both studies, we found evidence for the stigma‐asymmetry effect—incremental, relative to entity beliefs/messages of weight predicted both (a) stronger onset responsibility attributions, indirectly increasing body shame and (b) stronger offset efficacy attributions, indirectly decreasing body shame. Study 2 replicated the stigma‐asymmetry effect with anti‐fat attitudes. We discuss implications for public health obesity messages with the goal of reducing stigma.