Palatability affects satiation but not satiety.

The present study was designed to investigate the effect of the pleasantness of a food on satiation (meal termination) and satiety. It was also studied whether or not the subsequent availability of other attractive foods affected the effect of palatability on intake. In a within-subjects repeated-measures design, 35 (26 female and 9 male) young healthy nonrestrained subjects consumed at lunchtime a preload consisting of tomato soup, and a buffet/test meal consisting of many attractive food items. Three factors were manipulated. The palatability of the preload was manipulated by varying the citric acid concentration of the soup at three levels: 0 (pleasant), 7.5 (less pleasant), and 15 (unpleasant) g citric acid/kg soup. Intake of the soup was either ad lib (for investigation of satiation), or standardized (350 g for women, and 500 g for men; for investigation of satiety). The third factor was the availability of other foods, manipulated by the amount of time between start of preload and start of the test meal (intermeal interval = IMI), which was set at two levels: 15 and 90 min. Subjects rated hunger and satiety feelings, before the preload, and in between preload and test meal. The results showed that the ad lib intakes of the less pleasant and unpleasant soups were about 65 and 40% of the intake of the pleasant soup. Subjects ingested about 20% more soup when the subjects had to wait for the test meal about 90 min, compared to the 15 min IMI condition. The availability of other foods had no effect on the effect of pleasantness on ad lib intake. There was also no effect of the pleasantness on subsequent satiety: hunger ratings and test meal intake were similar after the three standardized soups. One conclusion is that pleasantness of foods has an effect on satiation but not on subsequent satiety. A second conclusion is that people eat more of a food when they know that they have no access to other foods for a particular amount of time.