Hormonal and neural mechanisms of food reward, eating behaviour and obesity

Abstract

With rising rates of obesity, research continues to explore the contributions of homeostatic and hedonic mechanisms related to eating behaviour. In this Review, we synthesize the existing information on select biological mechanisms associated with reward-related food intake, dealing primarily with consumption of highly palatable foods. In addition to their established functions in normal feeding, three primary peripheral hormones (leptin, ghrelin and insulin) play important parts in food reward. Studies in laboratory animals and humans also show relationships between hyperphagia or obesity and neural pathways involved in reward. These findings have prompted questions regarding the possibility of addictive-like aspects in food consumption. Further exploration of this topic may help to explain aberrant eating patterns, such as binge eating, and provide insight into the current rates of overweight and obesity.

Emotional Eating, Binge Eating and Animal Models of Binge-Type Eating Disorders

“…For recent reviews regarding the role of these circuits in eating behaviour and reward, please see [24,25]. Also, please refer to [26] for an outline of the role of endocrine factors (i.e. leptin, ghrelin and insulin) on eating behaviour beyond the scope of this review.…”

Does Nutrient Sensing Determine How We “See” Food?

“…In addition to a dampening effect of HE/HF feeding on negative feedback, studies suggest that the reward value of nutrients also is disturbed in the obese state. When presented with highly palatable carbohydrates or lipids, obese models generally display increased avidity compared to lean controls [111], indicating an increased reward threshold in obesity. The most heavily implicated neural mechanism in these findings is impaired NAcc DA secretion [112,113].…”

Neuroscience of Reward: Implications for Food Addiction and Nutrition Policy

“…Moreover, in clinical studies, the Yale Food Addiction Scale (YFAS) identified common neural correlates of food and substance dependence [7,8]. Finally, conditioning has been found to play a central role in excessive seeking and taking of food and drugs in both humans and animals [6,9]. This said, the "food addiction" hypothesis is often criticized for the lack of a clear definition and generally inconsistent findings [10].…”

“…For example, there are a number of neurobiological similarities between behaviours reinforced by these foods and those reinforced by addictive drugs in laboratory animals [4][5][6]. Moreover, in clinical studies, the Yale Food Addiction Scale (YFAS) identified common neural correlates of food and substance dependence [7,8].…”