Energy requirements for maintenance and growth in 3- to 4-year-olds may be overestimated by existing equations

Objectives: To give appropriate dietary advice to preschool children, an estimation of their energy requirements for both maintenance and activity is needed. We compared energy requirements for maintenance, measured by indirect calorimetry against existing equations predicting these requirements in 3- to 4-year-old children. Methods: In 30 children (age 3.4 +/- 0.3) from the GECKO Drenthe cohort, height, weight, evening sleeping metabolic rate (SMR) (by indirect calorimetry), fat mass (FM), and fat-free mass (FFM) (by isotope dilution) were measured. For 25 children, a valid evening SMR was available as a measure for energy used for maintenance and growth. This SMR was compared with existing equations (Schofield, FAO/WHO/UNU, Oxford and Harris-Benedict). Correlations among SMR and weight, height, FM, and FFM were also calculated. Results: From the existing equations, significant higher values, ranging from 58 to 144 kcal/day, were calculated for the BMR compared with the measured SMR results, indicating 8% to 19% overestimation. This overestimation is higher at lower ranges of energy requirement. SMR was positively related to weight (r = 0.488, P = 0.013), height (r = 0.499, P = 0.011), and FFM (r = 0.482, P = 0.027), but not to FM (r = 0.211, P = 0.358). Conclusions: Existing equations show higher values for the energy used for maintenance in young children compared to the results of our measurements of the SMR. Energy used for maintenance is correlated with FFM and not with FM.