5. Energy requirements for recovery from infection

There seems to be a metabolic window during recovery in which appetite is increased and the rate of retention, at least for protein, may be as much as eight times the average daily requirement. What generally happens in infants and young children in developing countries, however, is that the diet is too marginal to permit repletion before another episode of infection depletes the child further.

Table 9 shows the large increase in caloric intake 2 and 8 weeks after recovery from diarrhea from various causes in Bangladesh children compared with their intakes during the acute stage (MOLLA et al., 1983). In this case, food was freely available. The children's preinfection dietary intake was unknown.

A UNU (1976) publication gives the energy cost of synthesizing a gram of lost protein as 7.5 kcal per gram and 11.6 kcal for replacing a gram of fat. JACKSON (1977) in Jamaica measured the energy cost of catch-up growth in children recovering from protein-energy malnutrition and found a range of 4 to 5 kcal per gram of weight gain, with 40% of this considered to be fat tissue and 60% lean body mass tissue. Elsewhere in this volume JACKSON (1990) presents evidence that the proportion of fat and protein gained is influenced by the protein/energy ratio. The authors of a UNU (1976) publication calculated that, under conditions prevailing in developing countries, a malnourished one-year-old child depleted by an infectious episode of 7 days' duration would need approximately 136 kcal/kg/d and 2.56 grams of protein/kg/d for repletion in 30 days. It should be noted that the same weight deficit without infection would have required less than one-third the amount of protein per kg/d, but approximately the same number of calories.

In a recent INCAP study, supplementation completely offset the negative effect of diarrhea! disease on the length of the infant, attesting to the importance of an adequate diet during the recovery period (LUTTER et al., 1989).