The independent and interacting effects of weight suppression and admission body mass index on treatment weight change in patients with anorexia nervosa or bulimia nervosa

A novel weight suppression score associates with distinct eating disorder and ultra-processed food symptoms compared to the traditional weight suppression measure among adults seeking outpatient nutrition counseling

BACKGROUND

Weight suppression has been defined as diet-induced weight loss, traditionally operationalized as the difference between one's highest and current weight. This concept has been studied in the context of eating disorders, but its value in predicting treatment outcomes has been inconsistent, which may be partially attributed to its calculation.

METHOD

The current study operationalizes a novel weight suppression score, reflecting the midpoint between the lowest and highest adult weights among adults (N = 287, ages 21-75, 73.9% women) seeking outpatient treatment for disordered eating. This report compared the traditional weight suppression calculation to the novel weight suppression score in a simulated dataset to model their differential distributions. Next, we analyzed shared and distinct clinical correlates of traditional weight suppression versus the novel weight suppression score using clinical intake data.

RESULTS

The novel weight suppression score was significantly associated with meeting criteria for both eating disorders and ultra-processed food addiction and was more sensitive to detecting clinically relevant eating disorder symptomatology. However, the novel weight suppression score (vs. traditional weight suppression) was associated with fewer ultra-processed food addiction symptoms.

CONCLUSION

The novel weight suppression score may be particularly relevant for those with eating disorders and ultra-processed food addiction, with more relevance to individual eating disorder compared to ultra-processed food addiction symptoms. Consideration of the novel weight suppression score in future research on eating behaviors should extend beyond just those with diagnosed eating disorders.

The Role of Weight Suppression in Intensive Enhanced Cognitive Behavioral Therapy for Adolescents with Anorexia Nervosa: A Longitudinal Study

The study aimed to establish the role of weight suppression in a cohort of adolescents with anorexia nervosa treated with intensive enhanced cognitive behavioral therapy (CBT-E). One hundred and twenty-eight adolescent patients with anorexia nervosa (128 females and 2 males), aged between 14 and 19 years, were recruited from consecutive referrals to a community-based eating disorder clinic offering intensive CBT-E. Weight, height, Eating Disorder Examination Questionnaire, and Brief Symptom Inventory scores were recorded at admission, end-of-treatment, and at a 20-week follow-up. In addition, the developmental weight suppression (DWS, difference between one's highest premorbid and current z-BMI, i.e., BMI z-scores) was calculated. The mean baseline z-BMI was -4.01 (SD = 2.27), and the mean DWS was 4.2 (SD = 2.3). One hundred and seven patients (83.4%) completed the treatment and showed both considerable weight gain and reduced scores for eating-disorder and general psychopathology. Among completers, 72.9% completed the 20-week follow-up and maintained the improvement reached at the end-of-treatment. DWS was negatively correlated with end-of-treatment and follow-up z-BMI. This indicates that weight suppression is a predictor of the BMI outcome of intensive CBT-E and confirms that this treatment is promising for adolescents with anorexia nervosa.

Traditional versus developmental measures of weight suppression: Exploring their relationships with bulimic psychopathology

OBJECTIVE

Weight suppression (WS) is related to a wide variety of eating disorder characteristics. However, individuals with eating disorders usually reach their highest premorbid weight while still developing physically. Therefore, a more sensitive index of individual differences in highest premorbid weight may be one that compares highest premorbid z-BMI to current z-BMI (called developmental weight suppression [DWS] here).

METHOD

In this exploratory study, we compared the relationships between traditional weight suppression (TWS) and DWS and a variety of measures related to bulimic psychopathology in 91 females (M age, 25.2; 60.5% White), with clinical or sub-clinical bulimia nervosa.

RESULTS

TWS and DWS were correlated (r = 0.40, p < 0.001). TWS was only significantly related to a measure of physical activity whereas DWS was related to 14 outcomes. DWS showed consistent positive relations with behavioural outcomes (e.g., binge eating) but consistent negative relations with cognitive/affective outcomes (e.g., weight concerns).

CONCLUSIONS

Findings indicated much more consistent relationships between the novel DWS measure and bulimic characteristics than with the TWS measure. DWS showed both positive and negative relations with bulimic symptoms, though these findings require replication to confirm their validity. Consistent evidence indicated that the two WS measures served as mutual suppressor variables.

The effect of weight suppression on eating behavior: Does the intentionality of weight loss matter?

Weight suppression (WS) has been consistently related to eating pathology. The weight loss that produces weight suppression has always been assumed to be intentional, but no study has tested whether unintentional weight loss would also be associated with eating pathology. The current study examined whether the association between WS and eating pathology may be moderated by intentionality of weight loss in a community-based sample of 520 adults. Participants were categorized into low WS (<5% weight loss from highest past weight), intentional, high WS (>5% intentional weight loss), and unintentional, high WS (>5% unintentional weight loss) groups. The intentional WS group reported greater restraint than the unintentional WS and low WS groups, and the low WS group reported greater restraint and more frequent loss-of-control (LOC) eating than those with unintentional WS. Further, WS was positively related to loss-of-control eating frequency only in the intentional WS group, and negatively associated with LOC eating frequency in the low WS group. Additionally, BMI was positively associated with LOC and binge eating frequency and restraint only in the low WS group. Given the relatively high prevalence of substantial but unintended weight loss found in this study, researchers studying weight suppression should consider asking about intentionality of weight loss and analyzing their data with and without unintentional weight suppressors included in the sample.

A new, developmentally-sensitive measure of weight suppression

OBJECTIVE

Weight suppression (WS) has demonstrated associations with numerous indices of eating behavior, psychopathology and eating disorder prognosis. However, because WS has traditionally been measured as a simple subtraction of current weight from highest past weight at adult height, this calculation is problematic for most individuals with disordered eating, who usually reach their highest past weight during adolescence. Here we propose a new method for computing WS to address this shortcoming, termed "developmental weight suppression" (DWS), and provide a web-based tool for ease of calculation.

METHOD

DWS is calculated as the difference between one's highest premorbid z-BMI (i.e., BMI z-score), and current z-BMI. z-BMIs were calculated using Cole's lambda-mu-sigma (LMS) approach, in accordance with LMS parameters publicly available from the Center for Disease Control (2010). A web-based user interface is available at https://niuxin.shinyapps.io/devws/, making its computation easier and its adoption by researchers simpler.

DISCUSSION

By using z-BMIs in place of weights, DWS is more sensitive to the developmentally-relevant factors of age, height, and sex. Preliminary findings suggest that DWS is more strongly related to measures of eating pathology and biological reactions to weight loss than traditionally-computed WS, although more research is needed to test this hypothesis.

Examining weight suppression as a predictor and moderator of intervention outcomes in an eating disorder and obesity prevention trial: A replication and extension study

Weight suppression (WS) predicts future weight gain and increases in eating disorder symptoms in community and clinical samples but has received minimal attention in obesity and eating disorder prevention programs. In a sample of emerging adults (N = 364) in a randomized controlled trial evaluating two obesity and eating disorder prevention interventions versus a control condition, this study aimed to replicate the findings that WS and its interaction with baseline BMI predict increases in weight and eating disorder symptoms and test a novel hypothesis that WS would moderate the effects of the interventions on change in weight and eating disorder symptoms. Participants completed assessments at baseline, post-intervention, 6-, 12-, and 24-months. WS was calculated as the difference between highest lifetime weight and baseline weight. WS interacted with baseline BMI to predict greater weight gain over 24-months, such that those with high WS and lower baseline BMI gained weight most rapidly. WS did not predict eating disorder symptom change and did not moderate the effects of the prevention programs. Given that individuals with WS are at increased risk for weight gain, expressly targeting this high-risk population with evidence-based obesity prevention programs may be useful. CLINICALTRIALS.GOV REGISTRATION: NCT01680224.

Lifetime Weight Characteristics of Adult Inpatients With Severe Anorexia Nervosa: Maximal Lifetime BMI Predicts Treatment Outcome

Background: The body mass index is a key predictor of treatment outcome in patients with anorexia nervosa. In adolescents, higher premorbid BMI is a strong predictor of a favorable treatment outcome. It is unclear whether this relationship holds true for adults with anorexia nervosa. Here, we examine adult patients with AN and investigate the lowest and highest lifetime BMI and weight suppression as predisposing factors for treatment outcome. Methods: We included 107 patients aged 17-56 with anorexia nervosa and tracked their BMI from admission to inpatient treatment, through discharge, to follow-up at 1-6 years. Illness history, including lowest and highest lifetime BMI were assessed prior to admission. We used multiple linear regression models with minimal or maximal lifetime BMI or weight suppression at admission as independent variables to predict BMI at admission, discharge and follow-up, while controlling for patients' age, sex, and duration of illness. Results: Low minimal BMI had a negative influence on the weight at admission, which in turn resulted in a lower BMI at discharge. Higher maximal BMI had a substantial positive influence on BMI at discharge and follow-up. Weight suppression was highly correlated with maximal BMI and showed similar effects to maximal BMI. Conclusion: Our findings strongly support a relationship between low minimal lifetime BMI and lower BMI at admission, and between higher maximal lifetime BMI or weight suppression and a positive treatment outcome, even years after discharge. Overall, maximal BMI emerged as the most important factor in predicting the weight course in adults with AN.

Weight suppression and weight maintenance following treatment of anorexia nervosa

OBJECTIVE

The value of weight suppression (WS) in predicting the course of anorexia nervosa (AN) is uncertain. The objective of this study was to determine, using data from a previously published study, whether patients who remain weight suppressed following restoration to a minimally normal weight are at greater risk for relapse.

METHOD

Following weight restoration, 93 women with AN were randomly assigned to receive fluoxetine or placebo along with cognitive behavioral therapy for 1 year. WS (highest adult weight minus current weight), body mass index (BMI), and their interaction were assessed as predictors of change in weight over the first 28 days, of successful weight maintenance at 6 and 12 months, and of time to relapse.

RESULTS

Neither WS nor its interaction with BMI predicted successful weight maintenance at 6 and 12 months, time to relapse, or weight change over the first 28 days following discharge.

DISCUSSION

This study found that WS does not substantially impact the likelihood of successful weight maintenance or time to relapse following restoration to a minimally normal weight in AN.