Unravelling the role and mechanism of adipokine and gastrointestinal signals in animal models in the nonhomeostatic control of energy homeostasis: Implications for binge eating disorder

Abstract

Central and peripheral signals regulating energy homeostasis interact tightly with neuronal pathways to modulate the hedonic component of food intake. Dysregulation of these interactions could explain the development of binge eating disorder (BED) and/or obesity and the increasing incidence of food addiction. In this review, we have highlighted the crucial role of peripheral hormones, such as leptin and ghrelin, among others, in these nonhomeostatic pathways. We have also emphasised the relevance of central cannabinoid pathway and lateral hypothalamus, with orexin and melanin‐concentrating hormone neurons, as the critical hub controlling motivation and reward. Throughout the manuscript, we have focused on mechanisms learned from animal models of BED/food addiction in order to understand how these peripheral signals can modulate the motivation to eat. Understanding these mechanisms could help us to develop new treatment options for BED and/or obesity.

Food addiction, eating addiction and eating disorders

“…Biological evidence suggests that the salt, sugars and fats contained within such highly palatable foods may have addictive potential via activating dopamine reward systems in the brain (2) . To this end, several different variables that may indicate the molecular, cellular and systems-level mechanisms (18) , reward mechanisms (19)(20)(21)(22)(23) , specific components of food (17,24,25) or diagnostic criteria for substance dependence in relation to eating behaviours (26)(27)(28) as an addiction have been recently examined. The alternative contention has focused on eating behaviours, rather than food.…”

Hypocretin/orexin modulates body weight and the metabolism of glucose and insulin

“…The number of hypothalamic neurons capable of producing Hcrts/orexins appears to be limited and has been reported to be less than 20 000 . Hcrts/orexins are implicated in a variety of biological functions including arousal, wakefulness, and the urge to take food . The process of wakefulness and arousal is achieved when Hcrts/orexins stimulate monoaminergic as well as cholinergic neurons in the brain stem …”

Is food addiction a predictor of treatment outcome among patients with eating disorder?

“…However, FA is receiving an increased interest and a growing body of research in the last years (Fernández‐Aranda, 2018). The concept of FA posits that individuals experience addictive‐like symptoms related to the consumption of high‐calorie/palatable foods (Bonder, Davis, Kuk, & Loxton, ; Davis, ; Meule, von Rezori, & Blechert, ; such as preoccupation with obtaining a desired food, excessive consumption of unhealthy foods despite adverse health consequences, craving, impaired control, tolerance, withdrawal, and distress/dysfunction; Fletcher & Kenny, ; Gordon, Ariel‐Donges, Bauman, & Merlo, ), and with biological–hormonal maintaining factors (Novelle & Diéguez, ; Peters et al, 2018). It has been related to other addictive disorders due to the parallels in the neurochemistry (Gearhardt 2016; Jiménez‐Murcia et al, ; Tomasi et al, ), specifically in terms of participation of the dopaminergic reward system and the activation of positive reinforcement mechanisms (Carter & Davis, ; Racine, Hagan, & Schell, ; Volkow, Wang, Fowler, Tomasi, & Baler, ).…”