Maryam Alinezhad-Namaghi - International UNESCO Center for Health-Related Basic Sciences and Human Nutrition, Mashhad University of Medical Sciences, Mashhad, Iran.
Mohsen Nematy - Department of Nutrition, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
Toktam Sahranavard - International UNESCO Center for Health-Related Basic Sciences and Human Nutrition, Mashhad University of Medical Sciences, Mashhad, Iran.
Saeid Eslami - Pharmaceutical Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
Majid Khadem-rezaiyan - Department of Community Medicine, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
Mahdi Afarideh Sani - Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
Abdolreza Norouzy - Department of Nutrition, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.

Introduction: Most Ramadan fasting studies are usually conducted over one-year periods and show the short-term effects of Ramadan fasting. There is no standard tool or questionnaire to evaluate people's fasting habits and Ramadan fasting long term effects. For the first time, we designed a study to develop and validate a questionnaire to evaluate people's fasting habits as a tool for the determination of short-term and long-term Ramadan fasting effects. Methods: After designing the questionnaire, it was sent to ۱۰ experts in this field for judging and commenting (content validity). The validity of the questionnaire was evaluated using the Content Validity Ratio (CVR) index> ۰.۶۲, which includes the questionnaire's essentiality, relevancy, clarity, and comprehensiveness. In order to check the questionnaire reliability, the "test-retest method" was applied among ۱۰ individuals. Results: After multiple drafts, the questionnaire contained ۱۶ items, categorized into “Basic information on fasting (demographic information)”, and “Fasting nutritional habits” including ۱۳ and ۳ questions, respectively. The overall CVR for relevancy, clarity, and comprehensiveness of the tool were ۰.۹۲, ۰.۹۵, ۰.۹۷, and ۰.۹۵, respectively. The Pearson correlation coefficient of the test–retest stage was ۰.۸۵. Conclusions: This Ramadan fasting habits questionnaire demonstrated strong content validity and test-retest reliability. It can be an appropriate instrument for the evaluation of Ramadan fasting basic information and nutritional habits in research or practice-oriented settings for the determination of short-term and long-term Ramadan fasting effects.

Ramadan fasting, Questionnaire, Validity