Role of Endogenous Opioids in the Pathophysiology of Obesity and Eating Disorders.

This second chapter in our trilogy reviews and critically appraises the scientific evidence for the role of endogenous opioid system (EOS) activity in the onset and progression of both obesity and eating disorders. Defining features of normative eating and maladaptive eating behaviors are discussed as a foundation. We review the scientific literature pertaining to the predisposing risk factors and pathophysiology for obesity and eating disorders. Research targeting the association between obesity, disordered eating, and psychiatric comorbidities is reviewed. We conclude by discussing the involvement of endogenous opioids in neurobiological and behavior traits, and the clinical evidence for the role of the EOS in obesity and eating disorders.

Endogenous Opioids in the Homeostatic Regulation of Hunger, Satiety, and Hedonic Eating: Neurobiological Foundations.

This chapter (part one of a trilogy) summarizes the neurobiological foundations of endogenous opioids in the regulation of energy balance and eating behavior, dysregulation of which translates to maladaptive dietary responses in individuals with obesity and eating disorders, including anorexia, bulimia, and binge eating disorder. Knowledge of these neurobiological foundations is vital to researchers' and clinicians' understanding of pathophysiology as well as the science-based development of multidisciplinary diagnoses and treatments for obesity and eating disorders. We highlight mechanisms of endogenous opioids in both homeostatic and hedonic feeding behavior, review research on the dysregulation of food reward that plays a role in a wide array of obesity and disordered eating, and the clinical implications of neurobiological responses to food for current science-based treatments for obesity and eating disorders.

Integration of Endogenous Opioid System Research in the Interprofessional Diagnosis and Treatment of Obesity and Eating Disorders.

This third and final chapter in our trilogy introduces the clinical distinctions and phenotypical similarities between obesity and eating disorders. Research elaborating on the shared neurobiological substrates for obesity and eating disorders is discussed. We present an interprofessional model of treatment for both disordered eating and for obesity. Additionally, this chapter establishes the translational importance of research connecting endogenous opioid activity with both obesity and eating disorders, with an emphasis on clinical interventions. We conclude with a discussion of future directions for research.