The baby is a child under 1 year. Babies grow and develop particularly rapidly at this stage, which is the most vigorous stage in a person's life and weighs about 9000- 10000 grams. Babies have good sucking and swallowing functions when they are born at term, and there are thick fat pads on their cheeks, which are helpful for sucking activities, while premature babies are poor.

Sucking is a complex natural reflex, and serious diseases will affect sucking and make it weak. Babies have good sucking and swallowing functions when they are born at term, and there are thick fat pads on their cheeks, which are helpful for sucking activities, while premature babies are poor. Sucking is a complex natural reflex, and serious diseases will affect sucking and make it weak.

Newborns and infants have thin and tender oral mucosa, rich blood vessels, underdeveloped salivary glands, less saliva secretion, dry oral mucosa, and are vulnerable to injury and bacterial infection; Saliva secretion began to increase at 3 months; It increased significantly at 5 months. The content of amylase in saliva of children under 3 months is less, so it is not suitable to feed starchy food.

The gastric capacity of newborns is about 30-60ml, which increases with age, and it is 90- 150ml at 1 3 months and 250-300ml at1year. Because the stomach capacity of newborns is small, newborns should be fed several times, more often than older children. The baby's stomach is horizontal, and the position becomes vertical when he starts to walk.

Infant nutrition principles:

1. Because vitamin D can't enter breast milk through mammary glands, breast-fed children should take vitamin D supplements or get more sunshine 2 weeks after birth to prevent rickets. Long-term excessive intake of vitamin D will cause toxic reactions, so the recommended intake is 10 mg per day.

2. The iron stored in the baby's body is gradually consumed with development, and the iron content in breast milk is low. Iron-fortified baby cereal can be used as the first weaning food, and can also be eaten with milk powder added with lactoferrin to prevent iron deficiency anemia.

3. In view of the baby's need for protein and calcium, formula milk should be used as a supplement to energy, protein, calcium and other nutrients besides breast milk.

4, weaning food should avoid too much salt or seasoning, it is best to be original, to reduce the burden on the baby's kidneys.