Effects of changes in palatability on food intake and the cumulative food intake curve in man.

This study was undertaken to quantify the relationship between palatability ratings and food consumption and to determine whether the initial rate of eating was affected by changes in food palatability without a change in nutrient content. Both men and women were given small samples of foods at a brief exposure taste test and asked to rate how much they liked or disliked them on a 9-point scale (like extremely to dislike extremely). Those who gave at least a 2-point difference in rating between a banana colada frozen yogurt drink with and without adulteration with cumin were given these foods to eat to satiety on non-consecutive days, and the same 9-point scale was used to rate these foods after they had been eaten as meals. Cumin was used as an adulterant because it is not intrinsically unpalatable, but is not liked by many individuals in yogurt-based foods. Intake was approximately 100 g different for every unit of difference on the scale, and higher for liked than disliked food. Intake was significantly different between the adulterated and unadulterated meals. The percentage of variance explained by the difference in palatability was 34% of the total variance but was 67% of the variance within subjects. Correlation between intake and ratings were poor across subjects for both palatability levels (i.e. adulterated and unadulterated). The initial rate of eating was significantly higher under the better liked than under the less liked food. These results indicate that quantification of effects of hedonic ratings on intake within subjects is possible, but that hedonic ratings may not be good discriminators of intake differences between subjects. The initial rate of eating reflects partly on palatability.