Exploring the application of the Prototype Willingness Model to weight loss dieting behaviour among UK adults.

Frequent weight loss dieting leads to increased BMI and is associated with eating pathologies. Theoretical models can aid the development of interventions to reduce risk behaviours such as frequent dieting if they are able to adequately account for the target behaviour. The Prototype Willingness Model (PWM) may be able to account for weight loss dieting as this behaviour is often associated with social images. This study explored whether the PWM could predict weight loss dieting status over and above the Theory of Planned Behaviour (TPB). One hundred and ninety-two participants (69% female; mode age 35-44) completed PWM and TPB measures and recorded their height and weight. Males were more likely to be non-dieters than females. Frequent dieters had a higher BMI than non-dieters and rated themselves as more similar to the overweight prototype. Prototype perceptions predicted willingness to eat unhealthy foods alone. Similarity to the overweight prototype predicted weight loss dieting status over and above TPB measures and sex. Further research should explore prototype perceptions in an obese/overweight frequent dieting population as this may be a fruitful direction for developing interventions to reduce weight loss dieting.