I like to give the toddlers in my game egg-based dishes, especially Breakfast Scramble (Outdoor Retreat), but also Scrambled Eggs and Eggs and Toast and Spinach Frittata. Since almost all of my Sims garden, they also always have a healthly supply of excellent quality or better fruit in their inventory (Growfruit, Pears or Apples, but really any fruit will do) for emergencies and also to give them a quick happy moodlet which helps with building some of the skills. I actually have a lot of toddlers in my current save and I remember them eating Tofu Tacos and the Superfood Salad (requires Wellness skill to make) without any issue as well.