Translation, cross-cultural adaptation and validation of the Weight Management Questionnaire in the Brazilian population: a cross-sectional study.

Background: The prevalence of obesity has increased considerably worldwide, and it has become an important risk factor for chronic non-communicable diseases.

Bjective: To translate, cross-culturally adapt, and validate the Weight Management Questionnaire (WMQ) to evaluate weight control practices for health monitoring and intervention in Brazil.

Design and setting: This was a quantitative cross-sectional study.

Methods: Obese and physically active lean individuals aged 18-59 years were included in this study. The tool used as an adaptation was the WMQ. The cross-cultural adaptation was conducted in five phases. For structural validity, confirmatory factor analysis (CFA) was used to verify the internal structure considering two domains: diet and physical activity. To determine construct validity, a comparison was performed between different groups (lean versus obese). Reliability was assessed using the intraclass correlation coefficient (ICC).

Results: The short version of the WMQ after CFA presented eight items. Thus, the structure with two domains presented adequate fit indices: chi-square/degree of freedom = 1.66, comparative fit index = 0.996, Tucker-Lewis index = 0.994, root mean square error of approximation = 0.057, and standardized root mean square residual = 0.047. For construct validity, a significant difference was observed between the groups (P < 0.05) in both domains. We observed adequate reliability for both domains (ICC ≥ 0.854).

Conclusions: The WMQ can be used for the Brazilian population, as it is reliable and has adequate internal structure, supporting its use in future research.