Dietary variety impairs habituation in children

Abstract

Objective: The purpose of these studies was to test the hypothesis that dietary variety decreases the rate of habituation and increases energy intake in children.

Design: In Experiment 1, salivation in response to the same or a variety of food cues was measured followed by consumption of the study food(s). In Experiment 2, children responded in a computer task to earn points for the same or a variety of low or high energy density foods, which were then consumed.

Main outcome measures: Salivation, number of responses, and energy intake were measured.

Results: Participants in the same groups habituated faster than those in the variety groups (p = .05), and in Experiment 2, the effect of variety was independent of energy density. Participants in the variety groups also consumed more energy than those in the same groups in both experiments (p = .05).

Conclusions: Dietary variety disrupted habituation and increased energy intake in children. In addition, the response to dietary variety was independent of energy density, suggesting that increasing variety of low energy density foods may increase consumption.

Figure 1

Dietary variety disrupts salivary habituation and increases caloric consumption. A. (Top graph) Mean ± SEM salivation (grams) over nine presentations of olfactory food stimuli in a group presented with the same food for all trials (closed circles) or a variety of foods (open circles). ANCOVA showed that a significant Group × Time interaction in rate of change in salivation (p < .05), with participants in the Same food group, but not the Variety food group, significantly habituating. B. (Middle graph) Mean ± SEM number of Kcal and C. (Bottom graph) number of grams of food consumed during post-test consumption of study foods. ANCOVA revealed that the participants in the Variety group consumed significantly more energy and grams of food than those in the Same group (p = .037 and .007, respectively).

Figure 2

Dietary variety decreases the rate of habituation for motivated responding for food. A. (Top graph) Mean ± SEM number of responses made in each trial for access to food. ANCOVA revealed that subjects working for access to the Same food repeatedly (closed circles) habituated at a faster rate than those working for access to a Variety of foods (open circles), regardless of the energy density (ED) of the foods (p < .05). B. (Middle graph) Mean ± SEM Kcals consumed during the testing session. There was a main effect of variety (p = .002) and ED (p < .0001) and significant interaction between food variety and ED. Post-hoc analyses revealed that variety increased energy consumption in the high energy density (HED), but not the low energy density (LED) group (p = .003). C. (Bottom Graph) Mean ± SEM number of grams of food consumed during the test. ANCOVA analysis showed that subjects in the Variety groups consumed significantly more grams than those in the Same groups, but there was no effect of the ED of food (p < .05).