ABSTRACT. Energy partitioned to maintenance plus activity, tissue synthesis, and storage was measured in 41 children in early recovery [W/L (wtllength) < 5th percentile] from severe protein-energy malnutrition and in late recovery (WIL = 25th percentile) to determine energy requirements during catch-up growth. Metabolizable energy intake was measured by bomb calorimetry and metabolic collections. Energy expended (i f SD) for maintenance and activity estimated by the doubly labeled water method was 97 2 1 2 kcallkg F F M (fat-free mass) in early recovery and 9 8 f 12 kcallkg F F M in late recovery (p > 0.5). Energy stored was 5-6 kcal/g of wt gain. Tissue synthesis increased energy expenditure by I 2 0.7 kcallg 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 a s a function of initial body composition and rate and composition of wt gain.
50recommended, however, that new evaluations based on energy expenditure be made when methods and data become available (1). This need is particularly acute for malnourished children who enter into a period of rapid growth during treatment.Recently, the doubly labeled water method for measuring longterm daily energy expenditure was validated in preterm infants (2) and postsurgical infants (3). This method does not interfere with normal clinical treatment and thus provides the necessary component for new evaluations of energy requirements during recovery from malnutrition.During recovery from malnutrition, the required intake of matabolizable energy is partitioned between energy expenditure for maintenance and activity (m + a), energy expenditure for new tissue synthesis, and energy stored in new tissues. Because energy expenditure for m + a is partially dependent on fat-free mass (4) and because energy stored is dependent on the composition of the new tissue, concurrent measures of body composition would further facilitate the reevaluation of energy requirements. We therefore applied the doubly labeled water method to develop a model for predicting metabolizable energy requirements of children with growth failure secondary to proteinenergy malnutrition.
METHODSSubjects. Children studied (Table I) were from periurban areas of Lima, Peru, and were being treated for PEM in an in-patient metabolic ward. They were classified as being either in early recovery (W/L <5th NCHS percentile (5)) or in late recovery W/L = 25th NCHS percentile). Written consent was given by each child's parent or guardian. The protocol was approved by the University of Chicago Clinical Investigation Committee and the Ethical Review Committee of the Instituto de Investigaci6n Nutritional in Lima, Peru, where the studies were done.Criteria for admission to the study were height-age of 3 to 18 mo, wt deficit of at least 2.5 Z scores below the National Center for Health Statistics reference median for length (5), no detectable organic disease or edema, serum albumin >2.5 g/dL, and wt gain for 3 consecutive d...