Background: Hedonic hunger refers to consumption of food just for pleasure and not to maintain energy homeostasis. In this condition, the subject eats also when not in a state of short-term energy depletion, and food is consumed uniquely because of its gustatory rewarding properties. The physiological mechanisms underlying this eating behavior are not deeply understood, but endogenous rewarding mediators like ghrelin and endocannabinoids are likely involved. Objective and Design: To explore the role of these substances in hedonic eating, we measured changes in their plasma levels in eight satiated healthy subjects after ad libitum consumption of highly palatable food as compared with the consumption of nonpalatable food in isoenergetic amounts with the same nutrient composition of the palatable food. Results: The consumption of food for pleasure was characterized by increased peripheral levels of both the peptide ghrelin and the endocannabinoid 2-arachidonoyl-glycerol. Levels of the other endocannabinoid anandamide and of anandamide-related mediators oleoylethanolamide and palmitoylethanolamide, instead, progressively decreased after the ingestion of both highly pleasurable and isoenergetic nonpleasurable food. A positive correlation was found between plasma 2-arachidonoyl glycerol and ghrelin during hedonic but not nonhedonic, eating. Conclusions: The present preliminary findings suggest that when motivation to eat is generated by the availability of highly palatable food and not by food deprivation, a peripheral activation of two endogenous rewarding chemical signals is observed. Future research should confirm and extend our results to better understand the phenomenon of hedonic eating, which influences food intake and, ultimately, body mass.
Objective: Network theory considers mental disorders as the product of symptom interaction. A growing number of studies employing this methodology has been conducted in eating disorders (EDs). We aimed to review those studies to provide evidence and limitations for a novel conceptualisation of EDs.Methods: According to PRISMA guidelines and PICOS criteria, studies eligible for inclusion were those employing network analysis in people with a clinically defined diagnosis of ED. Twenty‐five studies were included and were analysed in relation to diagnosis, comorbidity, and treatment outcome.Results: Despite the central role of overvaluation of body shape and weight and cognitive restraint across ED diagnoses, ineffectiveness, interoceptive awareness and affective problems appear central symptoms. Ineffectiveness and interoceptive awareness emerge as bridge symptoms promoting comorbidity in people with anorexia nervosa and in mixed ED samples. Although few studies assessed treatment outcome, there is evidence supporting the predictive role of central network nodes.Conclusions: Ineffectiveness, interoceptive ability and affective problems may be included in the core ED psychopathology, in addition to ED‐specific symptoms. Network analysis is a promising method to reconceptualize comorbidity. Future studies are recommended to include general psychopathology in ED networks, to assess connections with the external field and clinical meaning of network connectivity.