Understanding the Use of Dietary Supplements among Athlete and Non-Athlete University Students: Development and Validation of a Questionnaire.

Background: The purpose of this study is to develop and test the validity and reliability of a questionnaire to evaluate dietary supplement use based on the Theory of Planned Behaviour (TPB).

Methods: The questionnaire has sections on demographics, physical activity, dietary supplements, and cognitive constructs based on the TPB. Three stages are followed.