*Article* **Lifetime Weight Course as a Phenotypic Marker of Severity and Therapeutic Response in Patients with Eating Disorders**

**Zaida Agüera 1,2,3,4,\*, Cristina Vintró-Alcaraz 1,2,3, Isabel Baenas 1,2,3, Roser Granero 1,5, Isabel Sánchez 1,2, Jéssica Sánchez-González 2, José M. Menchón 2,3,6,7, Susana Jiménez-Murcia 1,2,3,6, Janet Treasure <sup>8</sup> and Fernando Fernández-Aranda 1,2,3,6,\***


**Abstract:** The association between lifetime weight fluctuations and clinical characteristics has been widely studied in populations with eating disorders (ED). However, there is a lack of literature examining the potential role of weight course as a transdiagnostic factor in ED so far. Therefore, the aim of this study is to compare ED severity and treatment outcomes among four specific BMI profiles based on BMI-trajectories across the lifespan: (a) persistent obesity (OB-OB; (*n* = 74)), (b) obesity in the past but currently in a normal weight range (OB-NW; *n* = 156), (c) normal weight throughout the lifespan (NW-NW; *n* = 756), and (d) current obesity but previously at normal weight (NW-OB; *n* = 314). Lifetime obesity is associated with greater general psychopathology and personality traits such as low persistence and self-directedness, and high reward dependence. Additionally, greater extreme weight changes (NW-OB and OB-NW) were associated with higher psychopathology but not with greater ED severity. Higher dropout rates were found in the OB-OB group. These results shed new light on the BMI trajectory as a transdiagnostic feature playing a pivotal role in the severity and treatment outcome in patients with ED.

**Keywords:** body mass index (BMI) profiles; eating disorders; obesity; treatment outcome
