1. The dietary needs of a 9-month-old baby. When the baby is 9 months old, the baby\’s body and brain are developing rapidly and require sufficient nutrition to support their growth. At this time, the baby needs more energy and nutrients than before, so the dietary needs also change. In addition to continuing to feed breast milk or formula, other foods should be gradually introduced. 1. Protein: Protein is a necessary nutrient for building body tissues. At 9 months old, your baby needs about 11 grams of protein per day. Can be obtained through meat, fish, beans, eggs and other foods