Alternation between foods within a meal. Influence on satiation and consumption in humans

Food habituation/dishabituation has been observed in non-human primates in neurophysiological investigations of feeding, and in humans, through salivation or hedonic responses to food. The objective of the study was to evaluate in humans the effect of disruption of habituation by alternation between foods in a meal. Sixteen volunteers (8 males, 8 females; age: 21+/-1 yr; BMI: 21.5+/-0.5 kgm(-2)) ate a two-course meal [meatballs (M) and fries (F), then vanilla cream (C) and brownies (B)] during three randomized sessions. Sessions differed by the alternation of these foods: No-Repetition session with M-F-C-B; Single-Repetition session with F-M-F-B-C-B; Multiple-Repetition session with M-F-M-F-M-F-C-B-C-B-C-B. Final intakes of F and B were ad libitum. Quantities consumed (g, kJ) and ratings of hunger, pleasantness and desire to eat each food were evaluated. Compared to the No-Repetition session, subjects ate 18% more fries and 16% more brownies in the Single-Repetition, and 13% more fries but 20% less brownies in the Multiple-Repetition session. Pleasantness for the food decreased from before to after intake for both fries and brownies with no significant difference between the sessions. It therefore appears that moderate alternation between foods at lunch increases intake, but multiple alternations of foods at the end of the meal may decrease consumption. These differences in intakes could result from differences in sensory-specific satiety via disruption of habituation.