Weight History Correlates of Resting Energy Expenditure in Women With Bulimia Nervosa

Among those with bulimia nervosa, weight suppression has been associated with illness severity and treatment prognosis. Although significant weight loss is known to reduce metabolic rate, the relation between weight suppression and resting energy expenditure (REE) in bulimia nervosa has not been examined. This study tested the hypothesis of an inverse relation between weight suppression and REE in a sample of women with bulimia nervosa (N = 84).

In primary analyses, linear regressions were conducted between weight suppression and REE, corrected for fat-free mass. In follow-up, exploratory analyses, stepwise linear regressions were conducted to explore the main and interaction effects of weight history and weight suppression on REE.

Neither traditional (TWS) nor developmental weight suppression (DWS) correlated with REE. Results from exploratory analyses, however, revealed a medium-to-large inverse relation between several weight history variables and REE (highest past weight, sr² = 0.05; lowest postmorbid weight, sr² = 0.07; current weight, sr² = 0.05). Additionally, DWS interacted with current (sr² = 0.08) and highest premorbid (sr² = 0.05) z-BMI to influence REE with a medium-to-large effect. For individuals low in current and premorbid z-BMIs, higher DWS associated with lower REE levels. However, for individuals at higher premorbid z-BMIs, higher DWS unexpectedly associated with greater REE levels.

In this sample of women with bulimia nervosa, reduced REE associated with higher weights across all timepoints. If the interaction effect between DWS and z-BMI history persists in future studies, this may indicate unique challenges faced by individuals low in z-BMI and high in DWS related to weight gain and normalization of eating.