Also our dietician services were excellent at recommending sensory safe supplements. We get these spongebob fizzy drinks from superdrug for iron, to make up for the lack of meat eaten, and they talked to us about the 32 steps of eating which really helped us not make a big deal about if food wasn't consumed, and that interest in new foods is well into the 32 steps, and long before actually putting into into your mouth. This was revelationary to me as a worried parent, because it took a lot of stress away even seeing DS prod and poke the food, or use his hands to move it out of the way.
I also can't remember if it was a documentary I watched, or read something somewhere but there was something about what we consider food and it helped explain food anxiety in autistic people in a really clear way. I'll try and summarise.
So you might recognise chicken curry, or bolognese as food. In some parts of the world they will eat fried crickets, ants, and even chicks still in their eggs, or live octopus still squirming as you put it in your mouth. If you're not from those places, your brain will probably not automatically recognise that as food. In fact, you might even panic if you feel like you're forced to eat it. It might make you feel a bit queasy, uneasy, and repulsed to see a chicken foetus cooked in an egg being thrust infront of you while someone next to you eats it and tells you it's delicious. That instant lack of trust that something that is edible is food is what a lot of autistic people feel when some typical everyday foods are put infront of us. Our brains don't process the things infront of us as edible, even if those around us are eating it. You might eat something you've eaten for a long time, like a chicken stew, then one day the carrots or potatoes might not be fully cooked through, and it might have a bit of a crunch to it. No big deal to most people, but suddenly it isn't what your brain perceives as edible, and so there's that distrust sensation for that item of food.
Similarly, you might be given a chicken drumstick instead of a chicken breast, and when you bite into it you see the tendon or the vein, and it isn't what you usually find in chicken and the texture is a bit different so your subconscious tells you that is not food, it isn't edible, so now the only way you will eat chicken is once it's been ultra processed into a consistent uniform shape, flavour and texture.
ETA: Another example would be when you see some delicious cookies, you bite into them thinking it's chocolate chips, but it's oat and raisin! Suddenly you can't trust what you can see infront of you whenever you see chocolate chip cookies, because despite it being labelled chocolate chip cookies, and being reassured that it is chocolate chip, you will always think back to that time you bit into one and it wasn't yummy warm and gooey, it was crunchy and chewy and full of raisins.
This is what it's like being autistic and eating, except the window of foods you recognise as edible can be significantly smaller, and it's not something you can will away, it takes a lot of intensive therapy, like the Ellyn Satter-ish method our dietician recommended to us.