Exploring adults' dietary reporting accuracy using a repeated events framework

Self-reported dietary intake is commonly used to inform policy; however, memory-based reports are subject to error. Our aim was to examine dietary reporting errors using a repeated-events framework. Participants (N = 102) completed a 3-day food diary and 10 days later recalled what they had consumed on one self-nominated day and one experimenter-nominated day from the diary period. Self-nominated day reports were more accurate than experimenter-nominated day reports. Across both days, participants made more errors by reporting a food from the wrong day than by reporting foods not recorded in the diary at all. Unexpectedly, participants who completed their food-diary across Sunday-Monday-Tuesday were more accurate than those who completed across Thursday-Friday-Saturday, and participants who completed the study in 2020 were more accurate than those who completed it in 2021/2. Overall, results are consistent with the repeated events literature and outline a new approach to better understand dietary self-reporting.

Automated summary

Self-reported dietary intake is prone to errors due to memory-based reports. This study used a repeated-events framework to examine these errors and found that self-nominated day reports were more accurate than experimenter-nominated day reports. Participants often made errors by reporting a food from the wrong day rather than by omitting foods not recorded in the diary. Surprisingly, accuracy varied based on the days of the week and study completion year. Overall, these findings contribute to a better understanding of dietary self-reporting.