Well, that's up to you.
In our case, DS can't really have many of the "fun" foods at Disneyland, b/c he can't have corn syrup, high fructose corn syrup (both are in Uncrustables, and one or the other is in most ice creams including Mickey Bars and even Haagen Dasc toffee crunch bars sold at vendor carts) or corn syrup solids (Dole Whips). He goes nearly insane when he has any of those things, become a raging, circle-running, violent kid. Gosh that's not fun at Disneyland!
He can have the chocolate covered banana (encountered the nicest CM last trip who let me look at all the ingredients of her products), and I let him have cookies b/c the cookies don't seem to affect him (corn syrup is in most vanilla extracts, so the cookies might have it in the actual cookie, and if not, then likely in the chocolate chips) all that much.
As you can see, with all those "fun" foods off the list for him (and my husband, who nearly passes out when he has corn syrup or HFCS), you can see why we bring his normal snacks like safe granola bars!
If your family isn't used to things like that being fun (granola is actually quite sweet) then you're never going to convince them to eat them and it's all moot for you!