Just don't use high chairs. They only add to the frustration. At least without them, other Sims can "only" give the toddlers milk. But that still leaves the house littered with empty and stinky little cups after a while unless one of your Sims are neat
The way I feed my Sim toddlers is I take control of them and open the fridge, then place a plate with party servings in front of them, make them grab a serving and return the rest to the fridge. I pause my game during it (save for the grabbing) in order to keep the food fresh. I don't trust my parent Sims to feed the toddler with appropriate food. Using a high chair, they only seem to give the toddlers crackers and desserts at every meal which makes the little ones go nuts after a bit because their sugar-rush ends. So the kids get milk and food I choose, exclusively