Large serving sizes. Kids actually need a lot less than we think in most cases. If you have a toddler, a serving size of a food group is the same amount of tablespoons as they are in years. For example: a 2 year old- serving size of fruit= 2 T, serving size of veg = 2 T, serving size of protein = 2T, etc.
If you find your kids tend to OVER-eat, start with smaller portions and practice mindful eating together. Slow down while eating. You can make a game out of counting “chews”, drinking water before bites, putting the fork down between bites, etc. Also, always wait 20 min before offering seconds.