Objective: The aim of this study was to assess and compare eating disorder feature networks in adult and adolescent patients with anorexia nervosa. Methods: Patients seeking treatment for anorexia nervosa in inpatient and outpatient settings were consecutively recruited from Body mass index was measured, and each patient completed the Eating Disorder Examination Questionnaire. Results: The sample comprised 547 adolescent and 724 adult patients with anorexia nervosa. Network analysis showed that in both adults and adolescents, the most central and highly interconnected nodes in the network were related to shape overvaluation and desiring weight loss. The network comparison test identified similar global strength and network invariance, confirming the similarity of the two network structures. Discussion: The network structures in adult and adolescent patients with anorexia nervosa are similar, and lend weight to the cognitive behavioral theory that overvaluation of shape and weight is the core feature of anorexia nervosa psychopathology. K E Y W O R D S adolescent, adult, desiring weight loss, eating disorder psychopathology, feeling fat, shape overvaluation

Objective This study aimed to evaluate the presence of the overvaluation of shape and weight and its associated features in patients with obesity but no eating disorder who were seeking treatment from a specialist unit. Methods Overall, 1,134 patients with obesity but no Diagnostic and Statistical Manual of Mental Disorders eating disorder diagnosis were included. The Eating Disorder Examination interview was administered by expert clinicians to assess the eating disorder psychopathology and overvaluation of shape and weight. Patients also completed the Symptom Check List‐90‐Revised and the 36‐Item Short Form Health Survey to assess general psychopathology and quality of life, respectively. Results Roughly 20% of the patients with obesity presented with clinical overvaluation of shape and weight, which was associated with the female gender, higher expected weight loss, more severe eating‐related psychopathology, higher general psychopathology, and lower mental quality of life. Linear and logistic regression analyses indicated that the clinical variables independently correlated with overvaluation of shape and weight in these patients were female gender, Eating Disorder Examination Eating Concern subscale score, and 36‐Item Short Form Health Survey mental component summary score. Conclusions These findings are sufficient to justify routine assessment of overvaluation of shape and weight in patients seeking treatment for obesity.