Psychometric Testing of a Food Timing Questionnaire and Food Timing Screener

Abstract

Abstract Background Circadian rhythms coordinate multiple biological processes, and time of eating is an important entrainer of peripheral circadian clocks, including those in the gastrointestinal tract and liver. While time of eating can be assessed through valid and reliable tools designed to measure nutrient intake (24-hour recalls), currently there is no easily administered, valid, and reliable tool designed to specifically assess both time of food intake and sleep. Objectives The objective of this study was to test the validity and reliability of two questionnaires developed to measure food and sleep-wake timing, the Food Timing Questionnaire (FTQ) and Food Timing Screener (FTS), and the agreement between these two tools. Methods Content validity of these tools was assessed by an expert panel of 10 registered dietitian nutritionists. Adult volunteers (n = 61) completed both tools to assess internal consistency and test-retest reliability. Criterion-related validity was determined through the association of FTQ and FTS with two valid instruments, the Automated Self-Administered 24-hour (ASA24) Dietary Assessment tool and the Munich ChronoType Questionnaire. Agreement between the FTQ and FTS were tested by calculating the Pearson's correlation for both food and sleep-wake timing. Results The content validity index for both tools were greater than 0.80, and internal consistency and test-retest reliability coefficients were above 0.50 for all meals and sleep-wake times. Correlation coefficients were above 0.40 between both tools and criterion measures of food intake and sleep except for snacks. Correlations between FTQ and FTS on for all eating events and sleep were above 0.60 except for snack 1. Conclusions Both the FTQ and FTS are valid and reliable instruments for meal timing and sleep. However, further psychometric testing in a more expansive and diverse sample will improve the ability of these tools to accurately assess food timing and their impact on health outcomes. Summary This paper provides initial support for the use of a novel food timing questionnaire and screener to identify time of meal intake and sleep in a brief format.