Validation of Tools to Assess Predictors of Successful Weight Loss Outcome in Individuals With Overweight and Obesity.

Objective: To develop and validate questionnaires to assess the behavioral, psychosocial, and environmental predictors of successful weight loss outcomes.

Design: Mixed method study. Questionnaires were developed using 5 steps: item generation by literature review and preexisting questionnaires, expert evaluation, pilot testing, factor analysis, and internal consistency.

Setting: Adults with obesity recruited via web-based survey hyperlink.

Participants: One hundred participants with a mean body mass index of 28.7 ± 4.4 kg/m.

Variables Measured: The questionnaires were generated using 221 items. Establishing content, face and construct validity, and internal consistency.

Analysis: Content validity was analyzed using content validity index and content validity ratio, internal consistency through Cronbach α (CA), and structural validity by factor analysis via principal varimax rotation.

Results: All three questionnaires had good content validity. The Behavioral Predictor Questionnaire had good internal consistency (CA, 0.7) and excellent structural validity (69.7%). Psychosocial Predictors Questionnaire (CA, 0.8, 67.5%) and Environmental Predictors Questionnaire (CA: 0.8, 72.2%) had excellent internal consistency and structural validity.

Conclusion And Implication: Questionnaires seem to be practical, valid, and reliable tools for baseline assessment of individual-specific factors related to weight loss success.