Reducing the glycaemic load (GL) of the diet may benefit appetite control but its utility is complicated by psychological influences on eating. Disinhibited behaviour, a risk factor for overconsumption, is characterized by reduced prefrontal cortex activity, which in turn directly modulates vagal tone; a phenomenon inversely associated with blood glucose (BG) and insulin levels. This double blind randomised controlled trial explores the influence of disinhibited eating and vagal tone (heart rate variability) on the postprandial response to GL and hunger.