I hate the tone of this article!
Please don't force or push your child to eat foods that he/she finds disgusting! Support your child. Don't "take control" or "take charge." Your child is not your puppet. He/she is a person!!
Help your child take control of him/herself by experimenting and figuring out what components of various foods he/she likes and detests, and building on that. Maybe one kind of fish stick or pizza sauce or whatever tastes better than another because of spices/seasonings the second company uses. I only wish I had figured this out before I was well into adulthood. Now it is much easier for me to find/prepare food as I know which ingredients turn food from delicious to disgusting. I like plain meat. Putting ketchup on it, adding garlic salt, etc. makes it taste disgusting to me. It's not that there is something wrong with me. Everyone has different tastes.