Subtyping youngsters with obesity: A theory-based cluster analysis.

Psychological mechanisms play a crucial role in explaining weight gain. Aim of the present study was to identify subtypes in youngsters with obesity in line with these mechanisms. Defining homogeneous clusters within this heterogeneous group provides relevant information for personalized treatments. Data were collected in N = 572 participants (51% boys, aged 7-19) with extreme obesity (%BMI M = 187.8; SD = 30.9) recruited in an inpatient treatment centre. Based on psychological models of overweight/obesity, the Affect Regulation Model, the Reward Deficiency Model and The Dual Pathway Model, cluster variables were selected assessing emotional eating, reward reactivity and regulative capacities. Youngsters reported on emotional eating (DEBQ Emotional Eating) and reward sensitivity (BAS), while parents reported on children's regulative Executive Functions (BRIEF). Characteristics of the different clusters were examined concerning weight variables (pre and post treatment) and variables indexing problematic eating (DEBQ External Eating, Ch-EDE), affect regulation (FEEL-KJ) and depressive symptoms (CDI). Hierarchical cluster analyses supported the presence of three clusters, further evaluated by K-means cluster analyses. The cluster solutions differed according to age and sex (boys 7-13, boys 14-19, girls 7-13, girls 14-19). In all four age and gender subsamples, an "Emotional Eating" cluster displaying a vulnerable profile (high depression, maladaptive emotion regulation, problematic eating) and a "Reward Deficiency" cluster displaying a more resilient profile were detected. In girls 7-13, a "Weak Executive Functioning" indicative of insufficient self-regulative capacities, showed moderate to high emotional problems and problematic eating. In the other subgroups, the "Mean Level Functioning" cluster also showed elevated emotional problems and problematic eating. Given that different clusters can be identified, and given that these clusters have different profiles on emotional problems and problematic eating, subtyping youngsters with severe obesity is indicated, setting the stage for personalized treatments.