Background: Lower inhibitory control has been associated with obesity. One prediction is that lower inhibitory control underlies eating behaviours that promote increased energy intakes. This study examined the relationships between children's inhibitory control measured using the Stop Signal Task (SST), body composition and eating behaviours, which included self-served portion size, number of servings, eating rate, and energy intake at lunch and in an eating in the absence of hunger (EAH) task.
Methods: The sample included 255 6-year-old children from an Asian cohort. Stop-signal reaction time (SSRT) was used as an index of inhibitory control. Children participated in a recorded self-served lunchtime meal, followed by the EAH task where they were exposed to energy-dense snacks. Behavioural coding of oral processing was used to estimate eating rates (g/min). BMI, waist circumference and skinfolds were used as indices of adiposity.
Results: Children with lower inhibitory control tended to self-serve larger food portions (p = 0.054), had multiple food servings (p = 0.006) and significantly faster eating rates (p = 0.041). Inhibitory control did not predict energy intake at lunch (p = 0.17) or during the EAH task (p = 0.45), and was unrelated to measures of adiposity (p > 0.32). Twenty percent of the children in the sample had problems focusing on the SST and were described as 'restless'. Post-hoc analysis revealed that these children had lower inhibitory control (p < 0.001) and consumed more energy during the EAH task (p = 0.01), but did not differ in any other key outcomes from the rest of the sample (p > 0.1).
Conclusions: Children with lower inhibitory control showed a trend to select larger food portions, had multiple food servings and faster eating rates, but were equally as responsive to snacks served in the absence of hunger as children with better inhibitory control. Inhibitory control may impact a number of eating behaviours, not limited to energy-dense snacks.