Effect of dietary characteristics on food consumption in humans

The Specific Sensory Satiety Theory (SSST) has attempted to explain the mechanism of modification of self-regulatory behaviour (Hetherington & Rolls, 1996), proposing that subjects tend to consume a greater quantity of food when it has diverse sensory properties (varied diet). In contrast, subjects consume a smaller amount of food if it has similar sensory properties (monotonous diet). With regard to the effects of presenting diets with monotonous and varied sensory characteristics on humans, there are numerous studies that affirm that the availability of diverse foods is one of the factors that contribute to their overconsumption and, therefore, self-regulatory behaviours are not observed (McCrory, Fuss, McCallum, Yao, Vinken, Hays & Roberts, 1999; Rolls, 1985; Rolls, 2007). The main objective of this work was to experimentally evaluate the effect of foods with monotonous and varied sensory characteristics on food consumption in humans. To this end, three experiments were carried out: 1) Experiment 1: aimed to assess the consumption behaviour of monotonous and varied diets, presented in different sequences with intervals of approximately 23 hours between each presentation. Sixteen naïve experimental university students of both sexes, aged between 18 and 27, took part. The main results of Experiment 1 showed that the groups exposed to a single type of food presented a stable consumption. On the other hand, in the groups exposed to monotonous and varied foods, it was observed that the variety influenced the increase in consumption by the participants; Experiment 2: aimed to evaluate the effect of exposing the participants to monotonous or varied diets presented in different sequences with intervals of approximately 23 hours between each presentation. Sixteen naïve experimental university students of both sexes, aged between 18 and 27, took part; the main results showed that the groups exposed to the varied diet selected and consumed a greater quantity of food in comparison with the groups exposed to the monotonous diet, regardless of whether the food was provided simultaneously or successively. On the other hand, it was observed that the group exposed to monotonous foods simultaneously selected and consumed more foods than the group exposed to foods successively, while the group exposed to varied foods successively selected and consumed a greater quantity of foods in comparison to the group exposed to varied foods simultaneously. and, 3) Experiment 3: Experiment 2 was replicated with the following objectives: a) To evaluate the effects of exposing participants to monotonous or varied diets, simultaneously or successively, on consumption behaviour; and b) To identify the differences and/or similarities between the effects on the resulting behavioural parameters and the effects on the behavioural parameters observed in Experiment 2. Sixteen naïve experimental university students of both sexes, aged between 18 and 27, took part; the main results showed that the groups exposed to varied foods selected and consumed a greater quantity of food compared to the groups exposed to monotonous foods, regardless of whether the foods were provided simultaneously or successively. On the other hand, it was observed that the group exposed to monotonous foods simultaneously selected and consumed more portions than the group exposed to foods successively, while the group exposed to varied foods successively selected and consumed a greater number of portions compared to the group exposed to varied foods simultaneously.