my son only takes in approximately 200ml of formula milk and a three teaspoons of porridge between 8am to around 4pm. Is this adequate or am i starving my kid?
If this is all you are giving, it is too less. Are you giving only a total of 200 ml for the day? A 4 month old can easily have 200 ml milk four times a day, some spoons of porridge, juice. You can increase the diet day by day.