Palatability affects satiation but not satiety

The present study was designed to investigate the effect of the pleasantnes s of a food on satiation (meal termination) and satiety. It was also studie d whether or not the subsequent availability of other attractive foods affe cted the effect of palatability on intake. In a within-subjects repeated-me asures design, 35 (26 female and 9 male) young healthy nonrestrained subjec ts consumed at lunchtime a preload consisting of tomato soup, and a buffet/ test meal consisting of many attractive food items. Three factors were mani pulated. The palatability of the preload was manipulated by varying the cit ric 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 w as either ad lib (for investigation of satiation), or standardized (350 g f or women, and 500 g for men; for investigation of satiety). The third facto r was the availability of other foods, manipulated by the amount of time be tween 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 sa tiety feelings, before the preload, and in between preload and test meal. T he results showed that the ad lib intakes of the less pleasant and unpleasa nt 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 me al 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. T here was also no effect of the pleasantness on subsequent satiety: hunger r atings and test meal intake were similar after the three standardized soups . One conclusion is that pleasantness of foods has an effect on satiation b ut not on subsequent satiety. A second conclusion is that people eat more o f a food when they know that they have no access to other foods for a parti cular amount of time. (C) 1999 Elsevier Science Inc.