Pleasantness changes and food intake in a varied four-course meal.

Satiety can be specific to a food which has been eaten. This is shown by a decrease in the pleasantness of foods eaten relative to foods which have not been eaten. The aim of the present experiment was to determine whether this specificity still remained after a meal with a very different food in each of four courses. Forty-eight human subjects were given a four-course lunch with either a different food in each course (varied meal), or the same food in each course (plain meal). Energy intake was elevated by 60% in the varied meal primarily because of the increase food consumption in the third and fourth courses. The pleasantness of the taste of foods eaten decreased rapidly, whereas the pleasantness of foods which had not been eaten remained relatively unchanged. The change in pleasantness of a food correlated well with the subsequent intake of that food. Therefore, sensory-specific satiety is still found after eating four different courses in a meal and general satiety does not result. Some selective interactions between different foods were also found. For example, when a savory food was eaten, the pleasantness of (uneaten) savory foods decreased more than that of (uneaten) sweet foods. The converse was found when sweet foods were eaten. It is concluded that sensory-specific satiety and the effect of variety in enhancing food intake can operate throughout a meal with four very different foods, and that there are interactions between foods similar in savoriness or sweetness.