Influence of brain-stomach interactions on hunger, satiety and brain function
Hunger, satiety and feeding are complex phenomena exerting a profound influence on health and wellbeing. Hunger, or the mental urge to eat, is often associated with the feeling of an empty stomach. Satiety refers to a cascade of physiological, neural and metabolic mechanisms that inhibit further eating. Importantly, the decision making process in the brain that determines what, when and how much we eat is modulated by subconscious signals from the gut that can activate the brain’s dopaminergic system and reinforce dietary habits, explaining why so many people struggle to make healthy food choices and why the prevalence of obesity in developed countries is so high. Scientific knowledge on the brain-gut mechanisms behind hunger and satiety is incomplete, limiting our ability to develop efficient therapies and public policies targeting obesity and overweight. In BRAINSTOM, I have designed an innovative research program to study how the brain’s signatures of hunger and satiety are linked to the movements and contractions of the stomach, combining  my previous expertise in the simultaneous recording of the stomach and functional magnetic resonance imaging in humans with research methods from nutrition and metabolism and recent advances in positron emission tomography of the dopaminergic system. The three key hypotheses of my research proposal are that i) hunger feelings are associated with measurable changes in movements and contractions of the stomach ii) as food transits through the stomach, the brain releases dopamine and satiety feelings arise iii) the electrical activity of the stomach interacts with cortical, subcortical and neuromodulatory brain structures, influencing brain activity, interoception and cognitive functions beyond feeding. These findings will inform novel theories of brain-body interactions and will lead to the development of novel psychological and pharmacological interventions to reduce obesity and overweight.