Objectives: For this study, we adopted and expanded the Theory of Planned Behavior (TPB) by adding weight-related self-stigma (WSS) to explain avoidance in 3 eating behavior (EB) types – uncontrolled eating, emotional eating, and cognitive restraint – among overweight and obese persons and persons not overweight (underweight + normal weight). Methods: A total of 348 adults aged 18-30 years have participated in this study. Questionnaires were used to assess factors in TPB (viz, intention, attitude, subjective norm, and perceived behavioral control [PBC]) in relation to EB avoidance, WSS, and the 3 types of EB. In addition to structural equation modeling, path invariance was tested. Results: In general, WSS together with subjective norm and PBC were positively associated with intention to avoid EB; PBC to avoid EB was negatively associated with EB; however, intention to avoid EB and WSS were positively associated with EB. In addition, path invariance between the non-overweight and overweight groups was not supported. In the overweight group, WSS had a more significant impact on PBC. Conclusions: The extended TPB model successfully explained the intention to avoid EB and the negative effect caused by WSS. However, the intention-behavior gap emerged from our results. The underlying factors that prevent people from avoiding EB should be investigated further.