Are the dietary reference intake (DRI) values for estimated energy requirements (EER) accurate for girls in life stage group 9–13 years?

Abstract

We measured resting metabolic rate (RMR) by indirect calorimetry and daily total energy expenditure (TEE) by doubly labeled water (DLW) in 154 non‐obese pre‐menarcheal girls ages 9–12y. We compared EER based on the DRI equations to TEE measured by DLW. The level of physical activity (required to estimate EER) was based on the activity factor, TEE/RMR. 58% of subjects were pre‐pubertal (Tanner 1) and 71% were white. Mean (SD) age was 10.3(0.85) y, body fat was 23.1(5.2) %, TEE was 1962(277) kcal/d and EER was 1861(234) kcal/d. TEE and EER were highly correlated (Pearson r=0.79; p<0.0001). In unadjusted linear regression analysis, EER significantly predicted TEE (R2 =0.62; beta (SE) =0.93(0.06); p<0.0001). The association remained significant with adjustment for pubertal status and physical activity level (R2 = 0.67; beta (SE) = 1.08(0.09), p< 0.0001). To assess the accuracy of the DRI prediction equation we compared the individual‐level EER to the value of TEE from DLW. The mean (SD) difference between EER and TEE was −101(171) kcal/d and the average %difference was −4.6(8.5). 73% of participants had EER values within 10% of TEE. We conclude that for preadolescent girls the DRI equations predict well on a group basis. Use of these equations for individuals, however, may result in underestimation of energy requirements for a substantial proportion of girls. Supported by NIH grants MO1‐RR‐00088, DK‐HD50537 and 5P30 DK46200.