My kid has always liked most veggies. So we were lucky. If there was something he didnt like though I wouldnt force him to eat it. If he was however just holding out on something he'd never tried so he could just fill up on chicken nuggets or something, then he had to at least try it. If he didnt like he, he didnt have to eat it. I found with this approach he was much more willing to try various vegetables, and many he liked.
This more than anything established trust and taught him not to be afraid to try new foods; thereby eliminating the whole battle of wills thing. His cousin who is the same age grew up with the whole "eat it or sit there until you die" thing. He now subsists primarily on chicken strips and Oreos. How he doesn't have scurvy or rickets I'll never understand. But I've always stuck by the premise if my son tried it, and didnt like it, he didnt have to eat it. Sometimes, we'd require a certain number of bites, or a maybe an entire portion, but if he didn't like it, he didn't have to eat it. He's nearly 17 now, as and I'm proud of how much he's willing to try new things. There have even been instances where he didnt like something when he was little, but has gone back and tried them again years later and now loves them. Brussels sprouts and avocado are two examples. Now you might think your kid will always say they only like french fries, or nuggets; but once they realize theres no pressure, and you support their decision or taste, youll find its much easier, and there will be a ton of healthful foods they like.
My mom was "sit there until the stars go out in the sky". She once went to bed, and turned off all the lights in the house and left me sitting in the kitchen in the dark with my stuffed peppers.
We had a beagle hound named Hambone. (Best name ever for a hound dog btw). Id wait my parents out until the left the dining room and feed the dog small bites under the table. When I was about 11 my mom made some kind of goulash, or chili con carne, or something. Man it was God awful. I was left alone and ordered to sit there until I finished it. So when my parents were in the other room I crept in where we kept his food bowl and dumped the mess in Hambones dish. He took one sniff and left the room.
I got busted big time. I said, "Mom, look even the dog wont eat it!"
That was the last time I was forced to eat something I didn't like.