Coming from one who ate no fruits or vegetables from age 5-19, it could be worse. Let me say this, forcing the child to eat will not help, but you also can't completely give in. As an adult I am still challenged by a limited diet. Now as a mom I am faced with a son who wants to behave as I did and be a super picky eater. Having been the resistant kid, my response to this is a bit different than that of my parents. We talk alot about balanced diets, and the importance of getting food from all the food groups. It also helps that they kids have a grandmother who is a master chef and does wonders with fruits and vegetables - even makes Me want to eat them.
all of that said, here is our approach;
#1 - our house rule is that there are no special meals prepared for purposes other than allergies. dinner is what dinner is, this goes for breakfast, lunch and snacks as well. (a fatal mistake of my mother which although it avoided conflict, allowed me to maintain a very narrow food vocabulary for years).
#2 - Fruit is always allowed as a snack, unless meal time is within 1/2 hour -45 minutes. As a result, my son has developed a love for apples, apple sauce and oranges. Because if he didn't eat his meal, he can have that later.
#3 - When meal time is finished, the kitchen is closed. If you couldn't finish the food on your plate then there is no need for dessert or any alternative.
This last one is the tough part. When my son doesn't want to eat his dinner, we have to help him understand what his body is telling him. "sounds like you are still hungry, this is all there is until morning." "you seem tired, looks like you should have eaten some vegetables at dinner for more energy". And sometimes that means he goes to bed hungry. But breakfast time becomes a new opportunity to try again.
in the end we try to teach all of our kids to listen to their body and trust what it tells them. In the end, they make good choices. My son won't eat green beans, but he loves creamed spinach. He can't stand bananas but will gobble down a mixed fruit smoothie.
It's all in the presentation
good luck
It's a bit manipulative, but we try to stay honest about what foods do for him.
It works for me, and I am still