avocado toast is a winner for this one! it's healthy and fairly easy to make; it's been my go-to breakfast since i started making it a point to eat breakfast.
I only have suggestions for eggitarians and vegetarians, since I'm not non vegetarian, so here they are-
1. Eggitarians- Any snack/meal that includes eggs, fruits, and toast, along with almonds and cashews.
2. Vegetarian- A fruit or vegetable salad, toast, almonds and milk.
Something like just an apple can be great to have enough energy for the day or something with eggs because it's full of protein perfect to keeps you in form