A 9-month-old baby can start gradually introducing appropriate complementary foods. It is recommended that parents prepare some easily digestible, nutrient-rich foods such as rice porridge, fruit puree, and vegetable puree. At the same time, the baby still needs to consume an adequate amount of milk, with formula or breast milk remaining their main food source. Attention should be paid to a balanced diet in the baby’s meals to ensure they receive enough protein, fats, carbohydrates, vitamins, and minerals.