Ditto Mom2_4.
My nearly 5 year old son came home at 24lbs. He refused all food and drink and was perfectly willing to starve himself. He was doing a pretty good job of it, actually.
He is also on an antihistamine to give him a normal appetite. He receives a nutritional supplement (ensure plus) on a daily basis, in addition to his daily vitamin. These are non-negotiables, so I know that he has had a minimum of nutrition on any one day.
We are very careful that what we serve is not going to aggravate his sensory issues to the extreme, and is not beyond a reasonable amount for him to eat. Our nutritionist and OT regularly consult with us about this. Dinner is actually not the worst battlefield for us - that would be lunch and breakfast. We require time spent at the breakfast table, and that a vitamin and juice be eaten before school. I don't touch the lunch battle, although it becomes the after school snack when it comes home.
That said, not eating dinner has two major consequences:
1) Half the experience of a family dinner is the family. He is still expected to sit at the table and be pleasant.
2) If he has not eaten dinner, we assume he is absolutely exhausted, and he is sent straight to bed. Plenty of caring hugs and kisses on the way, but nothing else happens between dinner and bed.
So he is always welcome to let us know that he is just too exhausted to eat, but that is his choice. And he will still be subjected to our company
Again - Mom2_4 and I are both facing the extreme control battle version of not eating. Picky eaters are a different ballgame entirely.