Experimental analyses of the effects of variety in a meal on human feeding.

Satiety can be relatively specific to particular foods, and this is an important factor in influencing human food selection and the amount of food eaten. As a food is eaten, its taste and appearance decrease in pleasantness, but the taste and appearance of other foods remain relatively unchanged. The changes in pleasantness are highly correlated with the amounts of foods that will be eaten subsequently in a meal. Therefore more is eaten during a meal consisting of a variety of foods than during a meal with just one of the foods, even if that food is the favorite. This enhancement depends at least in part on the sensory properties of foods in that change in just the flavor or shape of foods affect intake. Although changes in the color of foods do not affect intake, the taste of colors that have been eaten becomes less pleasant and this probably affects food selection. The more dissimilar foods are, the greater the enhancement of intake by variety in a meal will be. As well as affecting food intake, the change in the pleasantness of foods which occurs while eating is an important determinant of food selection in that it promotes consumption of a varied diet.