Body composition and nutrition support in pediatrics: what to defend and how soon to begin

Specialized nutrition support is initiated during hospital care on the assumption that sparing the mobilization of body energy reserves is advantageous to recovery. The combined effects of disease and undernutrition on body cell mass, organ function, immune responsiveness, and wound healing are well documented in adults. Children cannot survive a fast as long as adults because of their lesser stores of energy substrates relative to the rate of energy expenditure. The present contribution attempts to estimate the rates of compositional losses for infants and prepubertal children on the basis of available data and reasonable metabolic assumptions. The lesson that emerges from this exercise is one of a very critical need for the early initiation of nutrition support for infants and children. The analysis suggests that an acute risk of protein depletion exists for children of all ages. Especially for infants, the empirical wisdom that "the absence of evidence is not evidence of absence" should be invoked to support early nutrition intervention. This work is submitted for critical review and revision to establish a consensus on the timeline of pediatric morbidity or mortality from semistarvation or starvation.