Variety influences habituation of motivated behavior for food and energy intake in children

Abstract

Background: Research has shown that variety reduces the rate of habituation, or a general reduction in the rate of responding, for low-energy-density (LED) and high-energy-density (HED) foods.

Objective: We assessed whether the effects of variety on habituation of motivation to eat are different in overweight and lean children.

Design: Overweight and lean children (n = 84) were randomly assigned to groups that varied as to whether they received their favorite or a variety of LED or HED foods.

Results: Habituation was slower for overweight than for nonoverweight children (P = 0.008), for a variety of foods than for the same foods (P < 0.001), and for LED than for HED foods (P < 0.001). Energy intake was greater for overweight than for nonoverweight children provided with variety (P = 0.004) and was greater for overweight or nonoverweight children provided with the same food (P < 0.001). A variety of HED foods increased energy intake more than did the same HED foods (P < 0.001); this increase was greater than energy intake with the same or a variety of LED foods (P < 0.001). Children who sensitized, or showed an increase in responding before habituating, showed slower habituation (P < 0.001) and consumed more energy (P = 0.039) than did children who did not sensitize.

Conclusions: Habituation is influenced by variety of foods, and overweight children increase energy intake more with variety than do leaner children. Research is needed to evaluate mechanisms of how variety influences the motivation to eat and energy intake, and how the variety effect can be used to influence intake across multiple eating occasions in children.

Figures

FIGURE 1

Motivated responding over time for variable ratio 120-s schedules of reinforcement for same (n = 41) or variety (n = 43) groups (mean ± SEM). Mixed regression models showed variety of foods (P < 0.001) influenced the rate of habituation.

FIGURE 2

Energy consumption (mean ± SEM) for children in the same (n = 41) and variety (n = 43) groups (top), and the interactions of same or variety and overweight status (middle), and same or variety × energy density (bottom). ANOVA showed greater energy intake for variety than for same (P < 0.0001). Contrasts showed greater energy intake for nonoverweight subjects provided with the same (n = 23) than for variety (n = 24; P < 0.001), and overweight subjects consumed more energy in variety (n = 19) than did nonoverweight subjects (n = 18; P = 0.004). Subjects provided with the same high-energy density foods consumed more calories than did subjects provided with the same (n = 20) or a variety (n = 21) of low-energy density foods (P < 0.001).

FIGURE 3

Motivated responding (mean ± SEM) on variable ratio 120-s schedules of reinforcement for children who did (n = 38) and did not (n = 46) sensitize with the definition of an increase in responding of ≥10% for minutes 3 and 4 compared with minutes 1 and 2. There was a significant difference in the rate of habituation between those who did and did not sensitize (P < 0.001).

FIGURE 4

Energy consumption (mean ± SEM) for subjects who did (n = 38) and did not (n = 46) sensitize during the habituation task. Children who sensitized consumed more food (P = 0.039).