I have 4 boys, and we have gone through "food protests" with all of them in the younger years. I'm not talking about "weird" stuff, like Brussel sprouts, but just the whims like one day he'll eat mac and cheese, the next time he won't. What we learned is that these protests (usually) have nothing to do with the food itself, and everything to do with control. So we have a policy in our family that works FABULOUSLY.
You know how some families make their kids sit at the dinner table until they're done (even if they're sitting there for 3 hours?) We decided against that approach - first, because sometimes that's just not possible with our schedule, and second, because sometimes a person is just legitimately full, and forcing a kid to eat more than they want can lead to obesity later on when they won't associate the full-feeling with stopping eating. So our policy is that if you don't want the food at this meal, you don't have to eat it now, but you get nothing else until the food is eaten. Here's how it works for us:
Let's say on Monday night I make baked macaroni, and green beans, and one of our guys doesn't want it. He doesn't have to eat it then, but obviously, he doesn't get any dessert or other snacks that night. Tuesday morning, he gets a basic breakfast (cereal), but doesn't get anything else until lunch, when the baked macaroni and/or green beans come back. If he still won't eat it for lunch, he doesn't get anything for snack, and it comes back at dinner. If they don't eat it for dinner Tuesday, it comes back for breakfast Weds. morning, and so it continues, until either they eat the food or it goes bad! Usually, by the second night (Tuesday, here), they're hungry enough to eat it, and then get whatever the rest of us are having for dinner if they want it. But with all four of our boys, the first couple times they tested us on this, it went a couple of days. The good news is you know they won't starve, and eventually they'll eat at least a little bit of it. The hard part is not giving in when they're sad, or throwing tantrums, or when you've made something for dinner on Weds night that they really really want. But after a few times, all of my kids just learned that there's no payoff to protesting, and the sooner they eat the food, the sooner they can get something else to eat!
Now, that said, as the kids have gotten older and been able to identify true likes and dislikes, I do try to at least pay attention to some of their natural preferences. Within reason. With 6 of us in the household, I can't be making 6 different meals, or even 2 or 3 different meals. But just like adults, we all have a few things we really don't like, and so for their top 1 or 2 least favorite items, I do try to accomodate. My oldest son just doesn't like rice, for example, so when I make rice, once in a while I'll let him pass altogether on the rice and fill up more on other items like veggies. Other times, I make him eat a smaller portion of the rice than his brothers, who happen to love rice.
While they were younger, I tended to stick to (a wide variety of) more generally-accepted kid friendly foods, but have gradually added more adult flavors, so now they don't balk every time something unfamiliar comes their way. It takes work and self-discipline not to give in, but it's been SO WORTH the payoff.
One other note, to balance out this approach, as the kids have gotten older I have included them in planning the menus for the week/month. I do this ahead of time for the week, not right before I'm about to make dinner. So on Saturday or Sunday, when I'm planning, I know I'm going to make chicken one day, I'll let them choose whether it's cornflake-chicken or salsa-chicken. And we make sure to plan in a few kid-friendly favorites throughout the month as special treats - pancakes one night, pizza another. And sometimes a true Kids Choice - where each kid gets to choose what he gets for dinner that night (usually one chooses Ramen Noodle soup, another chooses rice bowl, maybe another chooses frozen chicken nuggets). The point is, the kids know it's not a complete dictatorship, so they're more on board eating what I make on the other nights.
I truly hope this helps! Good luck!
*S.* SAHM of 4 boys ages 9,6,5,and 3