Calculating developmental weight suppression in practice: A commentary demonstrating the use and misuse of Singh and...

Eating disorders (ED) typically onset during youth, a critical period of growth and development. Maintenance of appropriate body weight is a criterion in multiple ED diagnoses and informs weight restoration. Data suggest that weight suppression (WS), the difference between an individual's highest historical and current weights, may be linked to ED severity and prognosis. Singh et al. (2021) formulated a developmentally-adjusted measure of WS using BMI z-scores to account for developmental growth during adolescence. Studies since have established both the face and incremental validity of developmental WS with respect to eating concerns, binge eating behavior, and abnormal endocrine and metabolic markers of ED, suggesting its benefit over traditional estimates of WS. Unfortunately, however, many studies have misapplied Singh et al.'s method by using z-scores based on highest premorbid weight, rather than using highest premorbid BMI z-score. This error can lead to underestimation of developmental WS. In this commentary, we present several case examples to demonstrate the importance of using growth chart data to identify the highest BMI z-score for the purpose of developmental WS calculation, as opposed to self-report highest past weight and height. We discuss how this procedure influences target weight calculation, the need for weight restoration in treatment, and diagnostic and clinical care considerations.