Diet and body composition of preterm infants

There have been few systematic studies of the effects of energy and protein intake on the body composition of preterm infants. Analysis of published studies suggests a roughly inverse relation between energy stored per gram of weight gain (a measure of the fatness of new tissues) and the ratio of protein to energy in the preterm infant's diet. At least within a certain range of energy and protein intakes, a higher protein diet promotes leaner body composition. Studies of the effects of varying the dietary ratio of carbohydrate to fat in preterm infants have shown reduced rates of carbon dioxide production with high-fat diets, fed by either the parenteral or enteral route. The little information available suggests no clear effect of varying the carbohydrate-to-fat ratio on body composition. The mineral content of the body can be influenced by diet. Insufficient intakes of calcium and phosphorus reduce the bone mineral content and thus the whole-body content of these minerals.