I think kids do come in different packages and it just is what
my pediatrician told me was to give my son lots of snacks besides just his meals. It doesn't seem to curtail him from eating breakfast lunch and dinner to have snacks. Find things that are healthy--- my kids just got into flavored beef jerkey which is low in fat and high in protein. We do protein bars, salty (nut) and sweet bars (honey and yogurt), cheese sticks, yogurt, etc. And I offer these things often.