Adaptation of the rapid weight loss questionnaire to the Turkish language: A validity and reliability study in weight classified athletes

Objectives: The purpose of weight classification in certain sports is to ensure safe and fair competition. However, some athletes attempt to gain an advantage by losing weight to compete in a lower weight category. The Rapid Weight Loss Questionnaire (RWLQ) assesses the weight loss status of athletes. This study aims to translate the RWLQ into Turkish (RWLQ-Tr), while ensuring its validity and reliability. Materials and Methods: Cross sectional study. Three independent experts translated the questionnaire from English into Turkish. The Turkish version of the questionnaire was obtained by translating the questionnaire into Turkish and then back into English. The translated questionnaire was then compared with the original questionnaire and harmonised. The content validity of the questionnaire was evaluated through expert opinion using the Davis method. At least 12 years old weight-classified sports athletes (n=330) were included in the pilot study. The RWLQ-Tr and the Dutch Eating Behaviour Questionnaire-Tr were administered simultaneously to the athletes participating in the pilot study. To assess reliability of the RWLQ-Tr, 93 athletes completed the questionnaire twice, with a 15-day interval. Results: The Content Validity Ratio value was found to be 0.994. Discriminant validity was established between the independent groups created based on weight loss below 4 kg (n=181) and above 4 kg (n=118), determined by the median value (50 th percentile is 4 kg) obtained from responses to the 14 th question of the RWLQ (p<0.05). There was no statistically significant difference in total scores between the test (31.0±12.3) and retest (30.5±12.2). The Bland-Altman plot test revealed a mean difference of -0.525 (p=0.318).