The present disclosure is directed to low calorie infant formulas and in particular low calorie infant formulas that have a low buffering capacity exhibit an increased rate of protein hydrolysis and digestion and have an improved tolerance as compared to full calorie infant formulas. Also disclosed are low calorie liquid infant formulas that have a reduced (i.e. low) micronutrient content on a per volume basis and exhibit an overall improvement in the physical properties of the formula as compared to low calorie liquid infant formulas having a higher micronutrient content.