I’ve got a pretty severe sensitivity to – of all things – sugar. (I know, “sugar” isn’t very precise, but I’m pretty sure it’s either glucose, fructose, or sucrose.) I virtually never eat anything with added sugar or anything with any significant amount of natural sugar. And I’ve eaten that way for like 20 years now. I’m practically blind to half the produce department (any “sweet” fruits like apples, pears, cherries, grapes, oranges, etc) at the grocery store, let alone the candy isle.
You want to start then of on single ingredients to get them used to different flavours and to check for allergies. It also has to be blended up smooth enough for them to eat, and at that point, it looks very different from what an adult would eat.