Where is the comfort in comfort foods: unraveling the neurophysiological underpinnings of human food reward in health and food intake disorders

 Although of great public health interest, the neurophysiological underpinnings of reward-based eating and their interplay with homeostatic mechanisms implicated in energy balance regulation are poorly understood, particularly when it comes to the role of different neurotransmitters. Dopamine (DA) and the endocannabinoid system (ECS) are considered key mediators of reward system responses to palatable foods, but human evidence is limited. The overall aim of this proposal is to establish the role of DA and the ECS, and their interactions with hunger/satiety hormones, in the psychobiology of human food intake regulation. First, I will disentangle the relative contribution of anticipatory (visual) and consummatory (oral) food reward and of oral and intragastric food administration on DA responses in the reward system of healthy subjects, and their predictive value for feeding behaviour. I will also translate this research to a clinical setting, by studying food-induced DA release in bulimia nervosa patients before and after treatment. Second, I will investigate the impact of BMI changes and accompanying alterations in endocannabinoid and hunger/satiety hormone levels on brain ECS receptor levels in a longitudinal interventional study in obese patients undergoing weight loss surgery. By taking an integrative approach, this proposal will increase our understanding of the psychobiology of human eating behaviour and may identify new treatment targets for obesity and bulimia nervosa.