Protein catabolism was studied in a group of premature infants some of whom were provided with a caloric intake soon after birth. The group given calories had a considerably decreased catabolism compared to the starved infants. Infants with respiratory distress were given calories as well and their catabolism was reduced below that of the starved group. The effects of catabolism and, particularly, of hyperkalemia on the heart of the infant suggest that it should be avoided. The conclusion from the study is that early caloric feeding of the premature is desirable.