Best weight gain for Pre-schooler

Hi parents! I would like to ask what is the most recommended weight gain milk or vitamins for a pre-schooler? My 4 year old son is taking Promil 3+. Do I need to change it to Promil Gold 3+ or Pediasure? His multivitamins are CeelinPlus and Propan TLC. Comment down below your suggestions. Salamat po.