Young infants do not have the necessary muscle control for proper processing and swallowing of solid foods. Around four to six months of age a baby begins to show signs of being ready, both behaviourally and developmentally, for learning new feeding skills. Introducing solids at this age exposes your baby to new textures and tastes and stimulates your baby to learn how to move things around in his mouth. The other important reason for introducing solids is to add a complementary source of iron to your baby's diet at the time when the amount of iron in his body is beginning to get low. However, at this time your baby continues to get most of the nutrition he needs from breastmilk or formula.
Babies let their parents know when they are ready for solids.
However, check with your doctor, as there are other reasons why weight gain may be slow. If your baby is gaining weight properly and your doctor confirms this, there is no need to start your baby on solid foods before six months. Solids Introduce one new food at a time and leave an interval of several days before introducing another. That way, if your child does have a reaction, you will know which food is responsible. Start with a small amount of each new food, about 1 teaspoon, and increase the amount as your baby becomes used to the food.