Theories of eating regulation often attribute overweight to a malfunction of homeostatic regulation of body weight. With the goal conflict model of eating, we present a new perspective that attributes the difficulty of chronic dieters (i.e., restrained eaters) in regulating their food intake to a conflict between 2 incompatible goals--namely, eating enjoyment and weight control. This model explains the findings of previous research and provides novel insights into the psychological mechanism responsible for both dietary failure and success. According to this model, although chronic dieters are motivated to pursue their weight control goal, they often fail in food-rich environments because they are surrounded by palatable food cues that strongly prime the goal of eating enjoyment. Due to the incompatibility of the eating enjoyment goal and the weight control goal, such increase in the activation of the eating enjoyment goal results in (a) an inhibition of the cognitive representation of the weight control goal and (b) preferential processing of palatable food stimuli. Both these processes interfere with the effective pursuit of the weight control goal and facilitate unhealthy eating. However, there is a minority of restrained eaters for whom, most likely due to past success in exerting self-control, tasty high-calorie food has become associated with weight control thoughts. For them, exposure to palatable food increases the accessibility of the weight control goal, enabling them to control their body weight in food-rich environments. Evidence for these proposed psychological mechanisms is provided, and implications for interventions are discussed. (Contains 6 figures and 8 footnotes.)