Energy intake and energy expenditure were assessed in 109 girls aged 8-12 y. Intake was estimated from a 7-d dietary record based on household measures. Expenditure was measured with the doubly labeled water technique during 2-wk period. Overall, the mean (+/-SD) energy intake was 7.0 +/- 1.67 MJ/d and the mean energy expenditure was 8.03 +/- 1.28 MJ/d. The mean difference between intake and expenditure was 1.03 +/- 1.77 MJ/d (P < 0.0001). The mean proportion of actual intake reported was 88.3 +/- 21.0%. Multivariate-regression analysis showed that age and total daily energy expenditure were significantly and independently related to the reporting error. Coefficients for age and total daily energy expenditure were both positive, indicating that as age and daily energy expenditure increased, the magnitude of the error of reporting increased. Income, ethnicity, parental obesity, and body fat were not significantly related to accuracy of reporting. The use of food records to determine energy intake appears to provide more accurate results in younger than in older girls, and the accuracy of the method apparently decreases as energy expenditure increases.