A Multi-Site Study of Brief Cognitive-Behavioural Therapy for Eating Disorders for Individuals With BMI ≥ 30

Area of Science:

• Psychiatry
• Clinical Psychology
• Eating Disorder Research

Background:

• Concerns exist regarding the appropriateness of cognitive-behavioural therapy for the treatment of eating disorders (CBT-T) for individuals with higher body mass index (BMI).
• Existing research has not sufficiently explored the differential effectiveness and acceptability of CBT-T across various BMI categories.

Purpose of the Study:

• To evaluate the acceptability and effectiveness of CBT-T in individuals with eating disorders across different BMI categories.
• To test the hypothesis that individuals with a BMI ≥ 30 kg/m² would exhibit higher dropout rates and reduced symptom improvement compared to those with a BMI < 30 kg/m².

Main Methods:

• A multisite study involving participants with non-underweight eating disorders in the USA (n=63) and UK (n=58).
• Participants received CBT-T and completed the Eating Disorder-15 (ED-15) to assess changes in behaviors (binge eating, purging, restriction, excessive exercise) and cognitions (Eating Concern, Weight/Shape Concern, Global Score).
• Data were analyzed comparing outcomes between BMI categories (≥ 30 kg/m² vs. < 30 kg/m²).

Main Results:

• Contrary to hypotheses, CBT-T completion rates did not differ significantly between BMI categories.
• Participants showed substantial reductions in binge eating, excessive exercise, and eating disorder cognitions, with no significant differences observed based on BMI.
• While the higher-BMI group (≥ 30 kg/m²) showed smaller reductions in restriction and purging (UK only), this was attributed to their lower baseline symptom severity.

Conclusions:

• This exploratory study found no evidence that CBT-T is less acceptable or effective for individuals in higher-weight bodies.
• Findings suggest CBT-T can be a viable treatment option for eating disorders regardless of patient BMI.