Yellow Rose, from my own experience, I say go with what your doctor says!
We have been through the same thing this past month, and after putting my foot down with "if you don't want it, that's all there is!" and letting meal times go without DS eating, he is now finally eating again!
I do know that lots of the problem stemmed from my husband getting overly stressed about meals and used to spend the entire meal time running around the kitchen offering him this, that, and the other: ie/ DS didn't eat his sweet potatoes, his chicken, his carrots or his eggs...so DH would start offering corn, peas, pears, bread, strawberries, and on and on and on until he decided DS had eaten enough that he wouldn't be hungry. We argued continuously about this, but it didn't stop him. In the end, DS decided that he liked bread. And pretty much, ONLY BREAD. So, after me attempting to offer a meal to DS, DH would get out the bread and DS would fill up on that - rolls, toast, sliced, freshly baked, you name it, he got his bread.
That turned into meal times being more or less bread and bread only. After two or three days I was more up the wall than before, and it finally turned into DS going two days without pooping, and insisting that the only thing he would eat was bread, followed by a dessert of fruit. So, I put my foot down -- with both DS and DH. I made up a menu, stuck it to the fridge, and made sure that as much as possible, I did dinner early before DH got home from work. If DH insisted on having bread with his own meal then we had to eat dinner after DS went to bed, or DH could take his bread and eat it in the bathroom
On my little menu I made sure that there was ONE thing that I KNEW that DS would for sure eat - for instance, corn. Everything else was a reasonable choice for a toddler. And I limited the portions of it - if corn is on the menu, he gets a reasonable serving of corn, and if he doesn't eat the other things that are on offer, he can't just sit there and eat 4 adult portions of corn IYKWIM.
First night, he ate nothing from his dinner but a few peas. Breakfast the next day was pancakes and blueberries - he didn't want the pancakes but did want the blueberries. I gave him a small handful - reasonable serving size to compliment the pancakes which were really the "meal" and made sure they were put away in the fridge so he couldn't just eat a pint of them to fill up. By the time lunch came, after two meals skipped, he inhaled a tuna sandwich - he HATES tuna. He ate it all, shouted for more, and ate a second tuna sandwich. Didn't pick the tuna off and throw it on the floor like usual. For dinner, that night, he tried a couple of things, didn't like them and only ate the slice of cheese that was "on the menu." But nothing else. Next day he wouldn't eat breakfast (scrambled eggs) OR lunch (can't remember what it was, but he had very little of one thing that was on offer and that was it). By dinner, he most all of what I offered, tried a bunch of new things because he was desperate enough, and surprised us both.
He is screaming hungry for his milk in the mornings but after three or four days, he will now eat pretty much anything I put in front of him again. I figured he would go two weeks without eating, on hunger strike to get what he wanted, but it took about three days.
I do think it is important to offer one thing that he will definitely eat at his meal, but to limit the portion to a reasonable sized amount of that item, and let him refuse the other things if he chooses to.
At one year old, I don't think that NWs will result from one day of poor eating. Offer a small snack between breakfast and lunch and again between lunch and dinner, and it will help to sustain him. Snacks we (now) go for are small pieces of fruit, a teething biscuit, a bit of cut up deli meat and bits of cheese, etc. Healthy, nutritious, but not filling enough that he won't eat a meal - just enough to keep him going between meals.
I know it is hard to do but it will be much harder the older he gets to break the habit of him choosing from a very limited variety of foods. The more variety you can offer him, the less he sees the same foods, and the more he comes to realise that this is it, the more willing he will be to try new things and realise he DOES like them!