Abstract
This study aimed to develop an extended model of goal-directed behavior (MGB) to more thoroughly explain the intention of adults to control body weight. The extended model integrates the crucial constructs and a newly added construct, mental health, as a formative second-order factor in the weight control context into the original MGB. An online survey was conducted with 239 undergraduate students, who responded to the constructs of attitude, subjective norms, anticipated emotions, desire, and mental health. A descriptive analysis was conducted, and the fit of the proposed research model was verified using structural equation modeling. The results showed that the known constructs of attitude, subjective norm, and anticipated emotions were critical predictors of desire in the context of weight control. In addition, desire influenced intention to control weight. Furthermore, mental health had a significant causal relationship with the variables in the extended goal-directed behavior. It broadens the weight control literature by emphasizing the role of affective factors in weight control behavior, expanding the MGB theory with mental health, and providing empirical evidence for an effective weight control intervention program.