How do you know when and how much solid food to feed your baby? he's 4 months already.

Delay until 6mo: Solid foods were once used to make up for deficiencies in home made milk formula used in the 50's to 80's.A return to breast FDG & modern formulas changed the value of solids from nutrition, to a pathway to teach baby to eat & transition to table foods.Waiting until 6m allows baby to sit & participate in a feeding, much as the will when older.Start with a few tablespoons as a paste.