A comparison was made of the effects on hunger and food intake of consuming preloads varying in sweetness and energy content. The preloads were a plain (unsweetened) yogurt, and the same yogurt sweetened to equal intensity with saccharin or glucose, or supplemented with starch. This balanced design made it possible to assess the consequences of adding sweetness to food as well as the consequences of substituting a nonnutritive sweetener for a caloric sweetener. Subjects (N = 24, repeated measures design) ate the preload at midday and returned one hour later for a sandwich lunch. Food intake in this meal was measured directly, and intake during the remaining part of the day was monitored using home recording in diaries. Hunger was assessed using subjective ratings of motivation to eat. Food intake at lunchtime was significantly greater following the saccharin compared with the plain preload, and parallel effects were revealed by the motivational ratings. Saccharin also stimulated further increases in intake after lunch. Food intake was lowest following the high-energy preloads, with the starch supplemented yogurt producing somewhat the largest suppression of intake. The results confirm and extend previous findings showing that intense sweeteners do not possess the same satiating capacity as glucose and sucrose. The stimulation of appetite by saccharin may be due to its sweet taste and also to effects on postingestive mechanisms.