17 Sensory specific satiety: variety seeking

Sensory-specific satiety was first described by Rolls et al. in 1981^[1]. They expected that a satiety mechanism existed specific to the foods just eaten. In their experiments, they found that the pleasantness of taste decreased during meals. And that if people were instructed to eat until satiation that they stopped eating just before people did not like the food anymore, that is when the foods became aversive. When subjects then tasted foods for a second meal, the pleasantness of its taste decreased more than that of other foods that were not eaten to satiety. Moreover, the decrease in ratings was specific to the food eaten, even if the uneaten foods had similar nutrient composition. In research after Rolls et al., it appeared that especially the sensory characteristics of foods explain this phenomenon. So this sensory satiety effect is also likely to transfer to products that are of similar, taste, smell, and texture. The explanation may be that this mechanism is responsible for long-term health and that this mechanism supports humans to keep a varied diet with a variety of nutrition. This finding also applies that more will be eaten of a varied meal (e.g. meal with different components or varied buffet) than of a single food. Then the question remains: Is this phenomenon is simply due to sensory adaptation or habituation? In short, the answer is no: eating more in a varied meal is not due to habituation or adaptation. In the studies of Rolls, it appeared that the subjects were still capable of sensing the differences in taste intensity after consumed until satiation, so there was no sensory fatigue after the meal.

Evolutionally, sensory-specific satiety is thought to help humans get all the necessary nutrients via nutrition. This way, people would not eat the same meal every day out of habituation, but they would switch food items.