Stick to your guns. Kids won't let themselves starve.
Every once in a while we skirmish with food. But the wife and I hold fast, and the kids remember that nothing has changed.
Here are our rules. Dinner is what is on your plate. We all eat the same meal. Eat it, or go hungry. You are not allowed to say nasty things about your food. That is rude. You may say, "I don't care for this," but not "yuck."
Now we cheat a little...If we have something exotic, or something that I KNOW the 4 year old will hate (i.e. pizza...WTF?), we are sure to put a decent portion of something on his plate that we know he likes (veges, fruit, & tortilla, etc). If he wants more of the kid-friendly stuff, he must eat the tiny amount of evil food on his plate too.
There have been some nights when the kid has gone to bed hungry. We remind him that it was his choice. But we don't ever force him to try something, and push it on him meal after meal. That's just not us.
Here is the second-most important thing about the way we do things (#1 is consistancy) - We do not fight about it. There is no raising of voices, gnashing of teeth or pounding of the table. We are matter of fact about it. Eat your food, or don't. Be civil or leave the table. Period.
Also, we praise the kids for trying new things, even if the things are yummy kid-stuff that they are obviously going to like. Try something new, get praise.
A great book to lauch the "new foods are neat" discussion is _Yoko_ by Rosemary Wells
http://www.amazon.com/exec/obidos/AS...031785-5055960