Do I need to introduce foods one at a time?

Believe it or not, the belief that introducing solids one at a time is becoming outdated, although most of the people still practice this. With my baby, I don't practice the 3-day rule. Why? Allergic reactions pop within a day so if my baby's allergic to something in the first place, you don't really have to wait for days. It's also a good idea to introduce your baby to lots of varieties but make sure to choose the appropriate ones for your kid's age.