B.P.
A nutritionist instructor told us(class) "it is our job as a daycare provider(parent) to offer our children nutritionally balanced meals. It is the child's job to eat...or not! A child WILL NOT let themselves starve." It takes a child up to 21 exposures to a food before they will decide whether they actually like it or not. Children's tastes change constantly. In addition texture, the way a food is prepared, how it is seasoned, and how it smells are also big factors. Something they love this week they may hate next week. What they like at 18 months old they may not at 2yrs but enjoy again at 2.5 yrs old. But you'll never know if it's never offered again.
I always required my kids to have one penny size bite of every item offered, actually chew and swallow. If they don't like it fine, they don't have to eat more. Of course you also have to deal with little nuances of childhood....like ~5 yr olds are notorious for not wanting their food to touch. Casserole type meals typically don't go over well. Example: typical Shepherd's pie- they may love hamburg, corn, mashed potatoes all separate on a plate, but put it together layered in a casserole….forget it...won't touch it, they hate it. Give the Shepherd's pie again in 7-8 months-no issues.
We also have to limit times kids eat. Kids need to be hungry at meal time. Have set meal/snack times; breakfast, mid-morning snack, lunch, mid-afternoon snack, evening meal. Limit juices...4oz of 100% juice is the serving size for an entire day for a child! Juice is empty calories, offer plain water instead.
Watch serving sizes; see this link to guides for child serving sizes:
http://www.fns.usda.gov/cnd/Care/ProgramBasics/Meals/Meal...
Many times portion we serve kids is way too much.