I'm a serious sensory seeker where food is concerned so if I don't attempt to curb what I eat, I hugely over eat. I'm not picky at all and like almost all food. The only positive of that is when I'm on a diet, I don't really feel restricted.
My severely autistic older brother has eaten the same meal for at least 30 years. He has crisps for his breakfast, something like toast or cheese and crackers for lunch and for dinner he has sausage, egg and peas. Every day. He will eat the odd yogurt.
He would literally refuse to eat anything else.