Body mass index, sex, interview protocol, and children's accuracy for reporting kilocalories observed eaten at school meals.

This pilot study investigated body mass index (BMI; calculated as kg/m(2)), sex, interview protocol, and children's accuracy for reporting kilocalories. Forty 4th-grade children (20 low-BMI: >or=5th and <50th percentiles, 10 boys, 15 African American; 20 high-BMI: >or=85th percentile, 10 boys, 15 African American) were observed eating school meals (breakfast, lunch) and interviewed either that evening about the prior 24 hours or the next morning about the previous day, with 10 low-BMI (5 boys) and 10 high-BMI (5 boys) children per interview protocol. Five kilocalorie variables were analyzed using separate four-factor (BMI group, sex, race, interview protocol) analyses of variance. No effects were found for reported or matched kilocalories. More kilocalories were observed (P<0.02) and omitted (P<0.05) by high-BMI than low-BMI children. For intruded kilocalories, means were smaller (better) for high-BMI girls than high-BMI boys, but larger for low-BMI girls than low-BMI boys (interaction P<0.04); low-BMI girls intruded the most while high-BMI girls intruded the least. For interview protocol, omitted and intruded kilocalories were higher (worse), although not significantly so (P values <0.11), for interviews about the previous day than the prior 24 hours. These results illuminate relations of BMI, sex, interview protocol, and children's reporting accuracy, and are consistent with results concerning BMI and sex from studies with adults.