When we go backpacking, we first gather to discuss the logistics, and part of that is meals. Each person knows what they like, I write them all down and order them online or head over to the camping section of Target or whatever. So, our meals are usually commercially-prepared individual or two-person portions. It's easy for us then, I just order 3 of this, 6 of that, 1 of the other thing. Sometimes, I'll buy an extra of something new just to try out. But everyone gets what they want, and we never have problems with picky eaters. Occasionally, someone doesn't like this brand or that, or would prefer a different brand offering. If the cost differential isn't that much, we'll absorb it, not a big deal for us. That's the scouting way.
This, of course, works when you are buying commercially prepared individualized meals, which can be more expensive than group meals - which might be what you are referring to. If this is the case, then I recommend to gather before the trip, and vote on a meal. Whoever are the minority votes, they have a choice: eat with the group and pay group rates; or they can separately purchase or prepare their own individual meals.
Everyone must understand that not all people can be satisfied all the time. Those who are difficult eaters must realize that their eating habits cause problems for others, as in cases like this. Therefore, expect some give and take, but the more choosey one is, the more give one will have to provide.
Do be sensitive to allergy, religious, or dietary requirements. What to do when the whole group wants ham and cheese sandwiches, and the one among you is Jewish. Or everyone wants peanut butter and jelly, but one person has allergies to peanuts.
In the end, the Jewish person may have to prepare his own sandwich. And the girl with the allergies... with severe allergy potential, she should be preparing her own foods anyway. And the fight over whether to get sugarfree snacks or sugared snacks? Work that in with a group decision. Compromises like "you'll burn off the sugar on a hike anyway" and "the whole purpose of a sugar snack is for energy, so why remove the energy from the energy snack" will have to come up, and you might decide on something altogether different with neither sugar nor carcinogenic chemical substitutes. ;-)