That’s not true about it definitely not being anorexia. I said up thread it sounds like ARFID, which may have tipped into anorectic behaviours. It is possible to have anorexia ride on the back of ARFID. This is exactly what happened to my dd.
The NHS like to put things into neat boxes as either / or, but it can be both. We are using a very experienced coach and former in patient ED mental health nurse to get dd to eat. At once stage, she was nil by mouth. Then would eat just 5 foods. Well 3 foods and the 2 others were a ‘treat’ day once a week to once every 10 days.
My dd does not eat just because there is food there that she can and will eat. It is far more complex than that.
It’s good your ds is eating a nutritious meal most days @BlueLoris. And that he cooked himself pizza. It at least has some tomato and protein. It’s interesting that you say he eats the vegetables first. My dd eats loads of grapes. And when she’s eating snacks (crisps, biscuits etc), she eats them first. I can’t make out why tbh. But there has to be a reason.
Good luck with the GP. If your ds does refuse to engage, you can go into the GP and get a form that you fill out for him to sign to confirm that you can advocate on his behalf. I got dd to sign it when she was 16/17. And I checked recently to see if it is still in place now she’s 18. It is.
Obviously with your ds, you’re talking adult services rather than CAMHS, which is a lot more difficult to get seen than CAMHS. However, it is worth talking to your GP at the very least. Do be aware that every post I’ve read on here about adult services says they discharge you if you don’t engage. But even if this happens, it is still worth trying, because it is doing something. And it’s all the doing somethings, which elicit change.
The advice to give your ds as much control as possible is good with you just nudging him along like you did with the pizza. And having a range of things, which are ready made / cooked and easy to grab and eat. Things like melon or pineapple ready chopped, grapes, cooked chicken breast / chunks of chicken (or even a whole chicken ready cooked in the supermarket if he will pick at that), ham slices, individually wrapped cheese eg babybel or sliced cheese, roasted vegetables that he can eat cold (preferably cooked in butter if he will eat that), potato salad (use a recipe with crème fraîche for the brain feeding dairy fats) steam fresh vegetables that he just needs to microwave as well as crisps, biscuits and chocolate etc.