Set-shifting ability across the spectrum of eating disorders and in overweight and obesity:A systematic review and meta-analysis

Background.In this meta-analysis we review the findings from neuropsychological studies on set-shifting in people with eating disorders (EDs) or overweight/obesity.Method.Four databases (PubMed, PsycINFO, PSYNDEX and Web of Science) were searched for eligible studies. Effect sizes (ESs) were pooled using random-effects models. Moderator analyses were conducted for ED and overweight/obese subgroups, adult/adolescent samples and measures of set-shifting.Results.Sixty-four studies with a total of 1825 ED patients [1394 anorexia nervosa (AN), 376 bulimia nervosa (BN) and 55 binge eating disorder (BED)] and 10 studies with a total of 449 overweight/obese individuals were included. The meta-analysis revealed a small to medium ES for inefficient set-shifting across all three ED diagnoses (Hedges’ g = –0.45). Subgroup analyses yielded small to medium ESs for each ED subtype (g = –0.44 for AN, –0.53 for BED, –0.50 for BN), which did not differ significantly. There was a medium ES for restricting type AN (ANR; g = –0.51) but no significant ES for binge/purge type AN (AN/BP; g = –0.18). A medium ES was found across obesity studies (g = –0.61). The ES across overweight studies was not significant (g = –0.07). Adult samples did not differ from adolescent samples in either ED or overweight/obesity studies. The different set-shifting measures were associated with largely varying ESs.Conclusions.The meta-analysis provides strong support that inefficient set-shifting is a salient neuropsychological phenomenon across ED subtypes and obesity, but is less prominent in AN/BP and overweight. Compulsivity seems to be a common underlying factor supporting a dimensional and transdiagnostic conceptualization of EDs and obesity.</jats:sec

Neural food reward processing in successful and unsuccessful weight maintenance.

Objective: Weight loss maintenance is one of the biggest challenges in behavioral weight loss programs. The present study aimed to examine metabolic influences on the mesolimbic reward system in people with successful and unsuccessful long-term weight loss maintenance. Methods: Thirty-three women with obesity at least 6 months after the completion of a diet were recruited: seventeen women were able to maintain their weight loss, whereas sixteen showed weight regain. Using functional magnetic resonance imaging in combination with the assessment of appetite-regulating hormones, neural reward processing during hunger and satiety was investigated. An incentive delay task was employed to investigate the expectation and receipt of both food-related and monetary reward. Results: Only participants with successful weight loss maintenance showed a satiety-induced attenuation of brain activation during the receipt of a food-related reward. Furthermore, in successful weight loss maintenance, the attenuation of active ghrelin levels was related to brain activation in response to food-related reward anticipation during satiety. Conclusions: The findings suggest that an attenuated influence of satiety signaling on the neural processing of food-related reward contributes to unsuccessful weight loss maintenance. Thus, intact satiety signaling to the mesolimbic reward system may serve as a promising target for tackling weight cycling

Integration of homeostatic signaling and food reward processing in the human brain.

BACKGROUND: Food intake is guided by homeostatic needs and by the reward value of food, yet the exact relation between the two remains unclear. The aim of this study was to investigate the influence of different metabolic states and hormonal satiety signaling on responses in neural reward networks. METHODS: Twenty-three healthy participants underwent functional magnetic resonance imaging while performing a task distinguishing between the anticipation and the receipt of either food- or monetary-related reward. Every participant was scanned twice in a counterbalanced fashion, both during a fasted state (after 24 hours fasting) and satiety. A functional connectivity analysis was performed to investigate the influence of satiety signaling on activation in neural reward networks. Blood samples were collected to assess hormonal satiety signaling. RESULTS: Fasting was associated with sensitization of the striatal reward system to the anticipation of food reward irrespective of reward magnitude. Furthermore, during satiety, individual ghrelin levels were associated with increased neural processing during the expectation of food-related reward. CONCLUSIONS: Our findings show that physiological hunger stimulates food consumption by specifically increasing neural processing during the expectation (i.e., incentive salience) but not the receipt of food-related reward. In addition, these findings suggest that ghrelin signaling influences hedonic-driven food intake by increasing neural reactivity during the expectation of food-related reward. These results provide insights into the neurobiological underpinnings of motivational processing and hedonic evaluation of food reward. TRIAL REGISTRATION: ClinicalTrials.gov NCT03081585