A new model for predicting energy requirements of children during catch-up growth developed using doubly labeled water

Abstract

Energy partitioned to maintenance plus activity, tissue synthesis, and storage was measured in 41 children in early recovery (W/L (wt/length) < 5th percentile] from severe protein-energy malnutrition and in late recovery (W/L = 25th percentile) to determine energy requirements during catch-up growth. Metabolizable energy intake was measured by bomb calorimetry and metabolic collections. Energy expended (x ± SD) for maintenance and activity estimated by the doubly labeled water method was 97 ± 12 kcal/kg FFM (fat-free mass) in early recovery and 98 ± 12 kcal/kg FFM in late recovery (p > 0.5). Energy stored was 5-6 kcal/g of wt gain. Tissue synthesis increased energy expenditure by 1 ± 0.7 kcal/g gain in both early and late recovery. From these data a mathematical model was developed to predict energy requirements for children during catch-up growth as a function of initial body composition and rate and composition of wt gain. The model for predicting metabolizable energy requirements is [(98 x FFM + A (11.1 B + 2.2 Q], kcal/ kg.d, where FFM is fat-free mass expressed as a percentage of body wt, A is wt gain (g/kg d), B and C are percentage of wt gain/100 as fat and FFM, respectively. The model was tested retrospectively in separate studies of malnourished children. © 1989 International Pediatric Research Foundation, Inc.