Eating Disinhibition and Vagal Tone and the Postprandial Response to Glycaemic Load

Hunger

Blood glucose

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.

There is growing recognition that lowering the glycaemic load of the diet might reduce a range of cardiovascular risk factors such as raised plasma triglycerides, HbA1c and C reactive protein and aid in body weight regulation. A proposed mechanism includes higher satiety and prolonged satiation by virtue of improved postprandial metabolic control, although, whether lower GL meals result in greater weight loss or increased satiety is still a matter of debate. One matter complicating the issue is that the desire to consume food may be driven by psychological factors; food reward centres in the brain may override hormonal regulation of food intake. Amongst psychological factors disinhibition has the largest and most consistent body of empirical data that associates it with weight gain although the mechanisms involved are unknown. This study will investigate whether, irrespective of BMI or habitual diet, disinhibited eaters have greater glycaemic excursions following a high glycaemic load drink and whether this predicts subsequent satiation.

United Kingdom