Notwithstanding the compelling body of literature confirming the importance of fronto-striatal networks as the neural correlates of inhibitory control, our results suggest that in the setting of obesity-associated T2DM, it is the impact of insulin resistance on brain networks driving go speeds (mGRT), rather than that of BMI on networks driving stop speeds (SSRT), that distinguishes obese individuals with poorer (shorter cSSD) from those with better overall impulse control (longer cSSD). The gene discussed is INS; the disease is type 2 diabetes mellitus.