Comparison of Self-Reported Dietary Recalls and Real-Time Tools to Track Mealtimes in Older Adults: A Pilot Study

Introduction: Meal timing can influence metabolism and health. Correct meal timing data is crucial to accurately assess eating patterns and develop effective interventions. However, commonly used methods like dietary recalls are often inaccurate for caloric and nutrient intake. In this pilot study, we aimed to assess the mealtime agreement between dietary recalls and documentation in real-time. Methods: This is an observational 2-week study in older adults with prediabetes and obesity. Participants reported their diet with (1) 2-6 non-consecutive dietary recalls (Automated Self-Administered 24-h (ASA24 ® ) Dietary Assessment Tool), and (2) time-stamped photographs of all caloric eating and drinking events via the myCircadianClock (mCC) mobile application. Data analysis was performed on days when both methods were used to assess the first eating occasion (FEO) and the last eating occasion (LEO) of the day. Significance set at P < .05. Results: Adults (n = 43, 14 men, age 60 ± 7 years, body mass index (BMI) 33.0 ± 6.2 kg/m 2 ) documented 4 ± 1 ASA24 recalls over 2 weeks. Agreement between tools ranged between 62% to 73% for the FEO and 49% to 61% for the LEO. The FEO and LEO agreement were positively correlated (β = .4, P = .01). Differences between tools were higher with fewer recalls (β = −.3, P = .04) for the LEO, but were not associated with age, sex, or body composition for neither the FEO or the LEO. The FEO agreement between tools was higher when the FEO was consumed earlier, when agreement was defined by ±45 min (estimate = −0.94, P = .001) and ±60 min (estimate = −1.11, P < .001). Conclusions: Our results suggest that mealtime agreement between dietary recalls and a time-stamped tool is consistently below 75%, and lowers for meals recorded later in the day. The inter-tool agreement is higher with increased overlap tolerance and greater number of dietary recalls. Clinical trials registration number: NCT04465721 https://clinicaltrials.gov/study/NCT04465721