As a final bit of "food for thought" for any supporters of the idea that parents somehow create their children's food issues - I have two children. DD has been raised in the same environment as DS, with the same parenting style, and she has always had precisely ZERO issues eating meat, vegies or anything else we dish up.
Nothing I wrote should be construed to discount the existence of things like food allergies. I am no expert in the field of eating disorders. I was focused on the original post, which sounds like a training problem to me. But food allergies and other physical or psychological problems could surely cause eating problems, and if you got from anything I wrote that eating problems cannot have a physical cause, I'm sorry. I certainly didn't mean to communicate that.
I guess it should also be obvious that someone can have some sort of sensory differences that could help to cause an eating disorder. (I would expect that to be quite rare, but perhaps among 2E children etc. it would be more prevalent than normal.) Even where something rare like that is present, I would not expect the environment to have zero impact. I guess that if a sensory disorder is severe, it can be quite hard to help the afflicted child eat more normally.
I also think it's obvious that someone can have a psychological or psychiatric problem that causes, partially or fully, an eating disorder.
Still, I think it should be obvious that learned behavior generally does have a
great deal to do with eating habits. This may be true even where some other cause exists for an eating problem. A particular person having one fussy eater out of two, where the fussiness was caused by what sounds like a somewhat major medical issue in your case, doesn't disprove that to me. Like everything else, children are individuals and one will need to be perceptive and responsive to each one's needs.
