Preterm infants fed human milk (HM) require additional calories and nutrients, as unfortified HM alone is inadequate to support optimal growth and body composition. Fortification methods have evolved to include targeted fortification (TF), based on measured macronutrient content of HM, rather than standard fortification (SF), which relies on assumed HM composition. The energy, protein-to-energy ratio, and macronutrient content of HM influence fat mass (FM) and fat-free mass (FFM) accretion, key factors for neurodevelopment and long-term metabolic health. This narrative literature review evaluated the impact of TF versus SF on body composition among preterm infants.