Background/objectives: To investigate the relationship of reporting accuracy in 24-h dietary recalls to child-respondent characteristics-cognitive ability, social desirability, body mass index (BMI) percentile and socioeconomic status (SES).
Subjects/methods: Fourth-grade children (mean age 10.1 years) were observed eating two school meals and interviewed about dietary intake for 24 h that included those meals. (Eight multiple-pass interview protocols operationalized the conditions of an experiment that crossed two retention intervals-short and long-with four prompts (ways of eliciting reports in the first pass)). Academic achievement-test scores indexed cognitive ability; social desirability was assessed by questionnaire; height and weight were measured to calculate BMI; nutrition-assistance program eligibility information was obtained to index SES. Reported intake was compared to observed intake to calculate measures of reporting accuracy for school meals at the food-item (omission rate; intrusion rate) and energy (correspondence rate; inflation ratio) levels. Complete data were available for 425 of 480 validation-study participants.
Results: Controlling for manipulated variables and other measured respondent characteristics, for one or more of the outcome variables, reporting accuracy increased with cognitive ability (omission rate, intrusion rate, correspondence rate, P<0.001), decreased with social desirability (correspondence rate, P<0.0004), decreased with BMI percentile (correspondence rate, P=0.001) and was better by higher- than by lower-SES children (intrusion rate, P=0.001). Some of these effects were moderated by interactions with retention interval and sex.
Conclusions: Children's dietary-reporting accuracy is systematically related to such respondent characteristics as cognitive ability, social desirability, BMI percentile and SES.