Shape & Weight Belief Experiment

When to use the Shape & Weight Belief Experiment

The Shape & Weight Belief Experiment is an interactive cognitive behavioural therapy (CBT) worksheet, most often used in CBT for eating disorders.

It is designed to be used within therapy rather than as a standalone self-help tool: a therapist introduces it, works through it collaboratively, and helps make sense of what it surfaces. You can preview the full worksheet above, then assign it digitally for clients to complete between sessions on any device — or download it as a print-ready PDF.

How it works

Most people work through it in around 15 minutes. It moves through three short steps:

1. Prediction
2. Experiment & Result
3. Reflection

Completed on the Formulate platform, your client's answers are saved automatically and shared straight back to you, so you can review them before the next session rather than waiting for a paper copy to come back.

The CBT approach behind it

In common with other CBT methods, the Shape & Weight Belief Experiment works by testing fearful predictions through real-world behavioural experiments. The aim is not positive thinking but a clearer, shared understanding of what keeps a difficulty going — and practical, testable ways to change it.

Because it is a CBT tool it stays focused on the here-and-now links between thoughts, feelings, the body and behaviour, and it works best as one part of a wider course of therapy rather than as advice or a diagnosis.

Evidence & sources

This worksheet is grounded in established cognitive behavioural therapy theory and practice. Key sources include:

• Fairburn, C.G. (2008). Cognitive Behavior Therapy and Eating Disorders. New York: Guilford Press.
• Fairburn, C.G., Cooper, Z., & Shafran, R. (2003). Cognitive behaviour therapy for eating disorders: A "transdiagnostic" theory and treatment. Behaviour Research and Therapy, 41(5), 509-528. doi:10.1016/S0005-7967(02)00088-8