Controlled Feeding With 24 Hour Recall

This prospective observational cohort study with repeated measures investigates the accuracy of self-reported dietary intake using the 24-hour dietary recall method, specifically the Automated Self-Administered 24-hour Dietary Assessment Tool (ASA-24). Research has consistently shown that individuals underreport energy intake using self-report tools, particularly those with overweight or obesity. However, there is limited understanding of which types of foods are most prone to misreporting and whether such tendencies are consistent across time or demographic groups.

To address these gaps, this study uses a controlled feeding protocol in which participants consume a standardized lunch consisting of two mixed dishes (chicken salad and macaroni and cheese with peas) and single-item foods (e.g., fruit snacks, saltine crackers, cookies, and a coke soft drink). All foods are weighed precisely before and after consumption to the nearest 0.01g. The following day, participants complete an online 24-hour dietary recall using ASA-24. This process is repeated one week later to assess reproducibility of reporting patterns.

The primary outcome is the portion-size reporting difference between actual and reported intake for each food item. Secondary outcomes include whether mixed dishes are more inaccurately reported than discrete foods, and whether underreporting is consistent across both sessions. Additional analyses will evaluate whether underreporting varies by BMI category, gender, or race.

Participants (N=65) are adults aged 18-65 recruited from the Texas Tech University community using flyers, email announcements, and word of mouth. Inclusion criteria include availability to attend lunch visits and complete online recalls. Exclusion criteria include food allergies or aversions to the test meal.