Validation of malay-chrononutrition questionnaire (M-CNQ) among adults in Malaysia

Chrononutrition relates food consumption to circadian cycles, which affect metabolism and health. Locally, there are not enough culturally and linguistically suitable methods to capture these behaviors. Malaysian adults' chrononutrition practices were examined using the self-administered Malay-Chrononutrition Questionnaire (M-CNQ). This multi-phase validation procedure included stage 1 forward & backward translation, stage 2 expert review & content validity, stage 3 face validity, and last stage are reliability testing. Ten experts assessed content validity, whereas 10 adults assessed face validity for clarity and relevance. A sample of Malaysian adults completed the questionnaire twice over a set time for reliability testing. CVI (Content Validity Index), FVI (Face Validity Index), Cronbach's alpha, ICC, and Bland–Altman plots were used in psychometric tests. An overall I-CVI of 0.97 and S-CVI/Ave of 0.98 indicated substantial expert agreement that the M-CNQ has excellent content and face validity. The item-level face validity index (FVI) ranged from 0.90 to 1.00, which was also outstanding. Instrument reliability testing demonstrated moderate to good internal consistency and test–retest reliability. Cronbach's alpha ranged from 0.20 to 0.67, and ICC scores across variables were 0.19 to 0.67, greater for meal time and frequency. Good behavioural category agreement between test and retest showed the tool's temporal stability. In conclusion, the Malay- Chrononutrition Questionnaire is reliable for studying time-based eating in Malaysian adults. It offers excellent potential for circadian health-based eating behavior therapies, public health surveillance, and academic study.