Thus, the committee considers that, ideally, formula should be tested for the entire period for which it is intended to be fed as the sole source of infant nutrition (up to 6 months or ≈180 days, consistent with breastfeeding guidelines) rather than the currently proposed 120- day period. Furthermore, the committee considers that a 120- day growth study may not be of sufficient length either to determine delayed effects or to understand longer- term effects of early perturbations in growth.