Fats are the major source of energy provided in breast milk, supplying roughly half of its total calories. Fats provide energy for growth, aid in the maturation of the infant's gut and central nervous system, and provide protection from pathogens, including group B streptococcus bacteria. Nearly 200 fatty acids have been identified in human breast milk. The structural configuration of these fats, which is not always replicated by many infant formulas, enhances their absorption in the infant's gut. All of these fats are encapsulated in fat globules surrounded by a triple layered structure called milk fat globule membrane or MFGM.

Components of the MFGM exert bioactive properties that confer many of the antibacterial in anti-inflammatory properties of breast milk. Unfortunately, most infant formulas do not contain MFGM. However, a recent clinical trial found that the bovine form of MFGM exerts similar beneficial effects on human infants when included in infant formula. The double-blind randomized control trial involved 451 healthy full-term infants who received either regular formula or formula containing MFGM and lactoferrin, an iron-binding protein found in human and cow's milk. At the end of the 18-month long study, the infants who received formula with the MFGM and lactoferrin scored higher on cognitive, language, and motor skills than infants who received ordinary formula. In fact, their scores were similar to those observed in children who were breastfed, suggesting that the addition of MFGM and lactoferrin could narrow the gap in cognitive development commonly observed between formula-fed infants and breastfed infants.