The present disclosure relates to methods of reducing the onset of allergies. In certain embodiments, the method includes administering to an infant a nutritional composition that includes a fat or lipid source, a carbohydrate source, a protein source comprising whey and casein proteins and, optionally, a probiotic. In certain embodiments, the whey:casein ratio in the protein source is from about 50:50 to about 70:30 and the degree of hydrolysis of the proteins included in the protein source is from about 4 % to about 10 %.