SummaryIntroductionIndividuals with overweight or obesity often experience stigmatizing weight‐related interactions in health care, though how these experiences are associated with body mass index (BMI) and eating behaviour is unknown. This study had three aims: (a) characterize types and frequency of stigmatizing health care experiences, (b) assess relationships among BMI, eating behaviour, and stigmatizing experiences, and (c) examine whether internalized weight stigma mediates the relationship between stigmatizing experiences, weight, and eating behaviour.MethodsAdults (N = 85) enrolled in behavioural weight loss completed measures of stigmatizing health care experiences, weight bias internalization, eating behaviours, and BMI. Cross‐sectional correlational and mediational analyses were conducted.ResultsThe majority (70.6%) of participants reported at least one stigmatizing health care experience in the past year. Greater amounts of stigmatizing experiences were associated with higher BMI (r = 0.32, P < .01) and greater uncontrolled (r = 0.22, P = .04) and emotional eating (r = 0.28, P < .01). Internalized weight stigma significantly mediated the relationship between stigmatizing experiences and maladaptive eating.ConclusionExperiences of health care weight stigma were associated with eating behaviour and BMI. Participants with a higher BMI or greater maladaptive eating behaviours may be more susceptible to stigmatizing experiences. Reducing internalized weight stigma and health care provider stigma may improve patient health outcomes.