Apologies in advance - this will be long.
DS(9) has always been a very fussy eater. We thought it’d improve as he got older but it hasn’t. Lately it’s got much worse & we’re now at a point where he’s barely eating anything at school or at teatime.
Today for example, school dinner was gammon, mash, veg - he doesn’t like mash or veg, he tasted the gammon but didn’t like it either so ate a slice of bread followed by chocolate concrete for pudding. For tea tonight I did chicken pie, chips, veg & gravy. He ate one chunk of chicken from the pie & that was it. Nothing else all evening before bed. This is a typical day for him. He will be desperately hungry in the morning & want several bowls of cereal plus toast to try to make up for it.
It has been this way for as long as I can remember. We had help from the health visitors when he was little - read all the books (my child won’t eat) & always tried to follow the advice that it’s our responsibility to provide the food & his choice whether to eat it or not.
We always used to clear the meal away without comment & offer nothing else til the next meal. It never improved what he ate. We find this hard to do these days - he is very vocal about disliking the foods & will spend the whole mealtime moaning. No matter how we try to avoid it, conversation is always drawn towards discussing what he is or isn’t eating. We’ve tried reasoning with him - discussing diet & why it’s important to eat a variety of foods etc. - it’s had no impact either, except probably to heap more pressure on 
Up to now we have always tried to include something within each meal that he will eat. However he accepts so few foods now this is becoming really difficult to do. E.g. if we do chilli & rice with veg & garlic bread he would eat nothing. If I served nachos with it he would eat only those - so just crisps for tea. Which isn’t exactly a healthy offering. Often I would just cook some pasta. But then we are getting into alternative meal territory & DD then complains she wants some too. Or questions she DS is allowed something different.
We’ve told him we can no longer do this - he either eats what we serve or goes completely without til the next meal. So far he’s chosen to do the latter. We’ve also limited breakfast to just one bowl of cereal plus toast plus fruit (which is a perfectly normal amount) to prevent him overloading at breakfast so he’s hungry enough for his other meals. Still hasn’t made him eat them.
We are both so worried about him. He’s very skinny. Within healthy weight range but only just. Noticeably smaller than his peers. Our DD(4) eats what I would call ‘normally’ & has way more than him at every meal. If he does eat, he always seems to need to dash up to the toilet to poo during the middle of the meal. I worry he is doing it to avoid being at the table. Mealtimes must feel awful to him.
This is what he will eat:
Breakfast cereals e.g. Cheerios, shreddies, weetabix, coco pops etc
White bread, croissants & brioche
Apples, strawberries & grapes
Jam (only sandwich filling he will have)
Plain Pasta
Plain chicken or chicken nuggets
Ham or Pepperoni Pizza (but only if not too tomatoey)
Plain Pork chipolata sausages
Bacon Quiche (minus the pastry)
Macaroni cheese
Tomato ketchup
Cheddar cheese - only grated on pasta
Crisps/snack bars/cakes/chocolate
Milk (only on cereal but caught him spitting it out this morning because he doesn’t like it
)
He’s lacking most fruits, any vegetables, rice or potatoes, pulses, nuts, most meats. I’m worried he is likely to be deficient in lots of vitamins etc.
We waver between
-thinking we need to be even more tough (stick with what we’re doing but without discussion & nothing (even fruit) til the next day)
- thinking he could possibly have sensory processing issues with food/texture, which case the advice would be the complete opposite I.e. give him what we know he will eat.
We don’t know how to improve things. We love him so much & want him to have a healthy relationship with food. And for him to eat a healthy balanced diet. Should we see a doctor? School haven’t been any help.
Where do we go from here? Any advice would be much appreciated.