Infant versus noninfant formulas and cow's milk: Transition based on age or weight?

Infant formulas are meant to be used until 1 year of age, at which point children are transitioned to non-infant formulas or cow's milk, depending on their remaining dietary intake. Noninfant formulas and cow's milk are appropriate for children who have an average weight at that 1-year mark (9-9.5 kg); however, can contribute significant protein and/or electrolytes to children who are underweight for age, particularly if they still rely heavily on formula feeding for their caloric intake. In this short communication, we present several cases of patients who received excessive amounts of nutrients for age following the formula transition at the 1-year mark. We also provide recommendations for clinicians to consider when faced with underweight infants who are meant to be transitioning off infant formulas.