Objectives: Prior research has demonstrated that executive function (EF) strength is positively associated with dietary self-control. As such, the differential operation of the brain centers underlying EFs (i.e., dorsolateral prefrontal cortex [DLPFC]) may explain controlled aspects of dietary self-control. The present study was designed to examine the causal relationship between DLPFC function and two aspects of dietary self-control: visceral cravings and actual consumptive behaviors.
Methods: The research was conducted using a within-participant design. A sample of 21 healthy female young adults aged 19 to 26 years (mean [M; standard deviation] = 21.10 [1.86] years) received both active and sham continuous theta burst stimulation (cTBS) to the left DLPFC. Before and after each session, subjective food cravings were assessed using the Food Craving Questionnaire-State. After each stimulation session, participants competed three measures of EF (Stroop, Go/No-Go, and Stop-Signal) and a bogus taste test.
Results: Participants reported larger increases in snack food cravings after active stimulation (M = 9.98% change, standard error [SE] = 0.45) than after sham stimulation (M = -3.46, SE = 0.39, p = .012) on the reinforcement anticipation dimension of Food Craving Questionnaire-State. Likewise, participants consumed significantly more snack foods after active stimulation (M = 70.62 grams, SE = 5.17) than after sham stimulation (M = 61.33, SE = 3.56, p = .006). Finally, performance on the Stroop task was reduced more after active (M = 71.56 milliseconds, SE = 25.18) than after sham stimulation (M = 20.16, SE = 13.32, p = .033); reduction in Stroop performance mediated the effect of active stimulation on increased appetitive food consumption.
Conclusion: These results support the contention that EF strength, as modulated by DLPFC activity, is causally associated with effective dietary self-control.