It is very important to follow the "four day wait" rule when introducing your baby to new solid foods. When you introduce a new food over the course of several days, you are better able to determine exactly how your baby is reacting to that food. This is most important if you and/or your family members have a history of food allergies.
Following the four day wait rule and introducing new foods one at a time will also enable you to easily begin an "elimination diet". If you suspect your infant has had an adverse reaction to a new food, you will have just a few foods to look to as the culprit.
Introduce new foods during the morning or early afternoon. This will enable you to deal with any adverse reactions when your pediatrician is in office. Should an adverse reaction occur during the morning/early afternoon, it will cause the least amount of disruption in baby's fragile routine.