Purpose of the Review <p>To examine evidence for factors that program and impact regulation of energy intake in infancy.</p> Recent Findings <p>Infants regulate energy intake within a narrow margin, and this capacity may degrade with age as volume-based regulation emerges. However, feeding frequency, milk/formula protein content and/or structure, portion size, and caregiver encouragement can interrupt this regulation. Emerging evidence also suggests that some infants exhibit signs of reward-driven eating, which may also affect energy intake.</p> Summary <p>Despite emphasis on obesity prevention in infancy, few studies directly examine milk/formula, food, or energy intake and even fewer use experimental methods to assess causation. Existing experimental evidence suggests a limited and diminishing regulation of energy intake through infancy and beyond. More research is needed to understand individual differences between infants in regulation of energy intake and propensity for reward-driven eating.</p>