Although high-intensity sweeteners are widely used to decrease the energy density of foods, little is known about how this affects hunger and food intake. We have studied the effects of consumption of commercially available foods sweetened with either sucrose or aspartame on subjective appetite ratings and food intake. When normal-weight non-dieting males and females were given large portions of either a high- or low-calorie pudding or jello and instructed to eat as much as they liked, they ate similar weights of the different caloric versions of each food. Despite the resulting difference in caloric intake (up to 206 kcal), subjects showed only a non-significant trend towards caloric compensation when presented with a variety of foods 2 h later. Total caloric intake (preload plus test meal) did not differ between conditions. Ratings of hunger, desire to eat, the amount subjects wanted to eat, and the pleasantness of the taste of the eaten food were similarly decreased and fullness similarly increased by consumption of the different caloric versions of the foods. Awareness of the caloric content of the foods did not influence intake or appetite in that both informed and uniformed subjects responded similarly in the tests. Thus reduced calorie foods suppressed ratings of hunger for several hours after consumption, but were not associated with a significant reduction in total energy intake.