Does Motivational Interviewing Improve Behavioral Weight Loss Outcomes for Obesity?

The semi-structured MI protocol was a 45-60 minute intervention based on general MI principles and guidelines, MI strategies specific to health care practice, and MI principles for obesity treatment. The MI protocol included the following components: (1) eliciting concerns about weight; (2) exploring ambivalence; (3) assessing importance and confidence for change; (4) writing a decisional balance; (5) bolstering self-efficacy; (6) looking towards the future; and (8) eliciting ideas for possible changes participant could make to work towards weight loss. Although there was slight variation, the protocol for both MI sessions consisted of similar components.

The attention control interview was a semi-structured interview ascertaining information relevant to health history, weight history, diet history, dietary and physical activity habits. The majority of questions for the control interviews were drawn from the Behavioural Weight Loss Program intake application. It was designed to be structurally equivalent to the MI session in terms of length of session, timing of sessions, and treatment modality. The goal of the attention-control interview was to provide a pseudo-intervention that controlled for factors common to attending treatment (e.g., attending treatment sessions, having personal contact with a therapist, discussing weight-related issues).