Does Real Time Variability in Inhibitory Control Drive Snacking Behavior? An Intensive Longitudinal Study

Objective: Laboratory eating studies and cross-sectional surveys indicate individuals with inefficient executive function (EF) consume more unhealthy snacks than others. However, the importance of EF in determining snacking behavior in the "real world" has not been established. Contemporary behavioral and self-control theories posit EF as a dynamic resource fluctuating over time. Consequently, a test of the relevance of EF to behavior within individuals is required. This study tested within- and between-person effects of real-time variability in objectively measured inhibitory control (a core facet of EF) on subsequent snacking behavior in daily life. Method: A community sample of 64 adults recorded snacking behavior and completed a short Go/No-Go test (assessing inhibitory control) hourly over 7 consecutive days, yielding a total well-powered sample of 6,284 data-points. Generalized linear mixed models using lagged effects examined within-person and between-person effects of inhibitory control efficiency on snacking behavior. Results: When Go/No-Go test responses were 100 ms slower than the person-mean (indicating periods of poorer inhibitory control), snack consumption in the following hour was 25.67% higher, Exp (γ) = 1.26, p = .002, 95% confidence interval (CI) [1.06, 1.49]. Between-individuals, person-mean reaction time (RT) did not predict snack consumption, Exp (γ) = 1.02, p = .965, 95% CI [0.71, 1.46]. Conclusions: RT variability in inhibitory control efficiency is highly relevant to snacking behavior within individuals. Inhibitory control is an important driver of snacking in everyday life and an important target for interventions.