Restraint theory has identified overeating in response to a high calorie preload as characteristic of restrained eaters. The present study evaluated cognitive and motivational changes to preloading using both self-report rating scales and Stroop tasks. The results suggest that the restrained eaters responded to a high calorie preload with increased feelings of rebelliousness, defiance, and a desire to challenge the limitations set by the diet, described as an active state of mind, as measured by both the Stroop task and the rating scales. The restrained eaters also showed retardation in the color naming of the body size words and food words after the high calorie preload, suggesting that the consumption of a forbidden food may increase the dieter's concern about food and her shape and weight. The results are discussed in terms of the effects of preloading and possible mediating variables involved in the transition from successful restraint to overeating.