Individuals using milk-based diets in refeeding programs occasionally report initial problems with diarrhea aggravated or precipitated by lactose. In this early phase, a hydrolyzed lactose or lactose-free milk may be optimal. Apparently, however, whole milk is successfully used for refeeding, unless there is severe diarrhea. This suggests that the milder cases seen out of the hospital may present less significant problems. The report by Mitchell et al.,45 however, suggests that the effect of lactose may be more subtle. Although unavailable lactose may not present major problems to fat and nitrogen absorption, the decrease in metabolizable energy may be enough to decrease the rate of weight gain, lengthen hospital stays, and therefore decrease the effectiveness of lactose in refeeding programs, unless compensated for in the total diet. Comparable studies should be repeated in hospital and supplementary feeding programs to determine whether or not potential effects on nutrient bioavailability are as significant as this study suggests.