The present disclosure provides a nutritional composition, such as a preterm infant formula that includes a protein source comprising whey protein and hydrolyzed casein protein. The whey protein to hydrolyzed casein ratio may be from about 90:10 to about 50:50 by weight. The hydrolyzed casein may have a degree of hydrolysis of from about 20% to about 80%. Additionally, provided are methods for improved gastric emptying and improved digestibility in a target subject, such as a preterm infant. When administered, the nutritional compositions may promote intestinal transit and absorptive capacity. Consequently, better growth and development, especially neurological development of the target subject may be achieved.