If he or she refuses to eat, don't make too much of a fuss, just take their plate away and don't give them anything else to eat until the next meal time, no matter how much they whine.
I have found that the more you stress about it and you must be stressing to ask about it, the more the child will pick up on this and refuse.....It is a kind of test that we all go through at some time.
I forgot to add this:
Forcing kids to eat is likely to cause or at least contribute to some long term food related issues. The last thing you want is to give your kid a complex about food. Let them eat when they're hungry and stop when they're full. Just don't let them say they're done with dinner and then give them cookies ten minutes later.
Give him an option. When he asks what is for dinner, say he has a choice of either lamb casserole (the meal you just cooked) or fish and celery pie (the meal you just invented). Guess which one he will choose?
We tell our son why the food he's eating will help him grow and be healthy - milk has calcium for strong bones, etc.
If he says he's not hungry, we say that's ok and let him get down from the table. We save his leftovers and that's the only thing he can eat until the next meal.
put there meal in front of them make sure evryone sits down for dinner and say whoever finishes there dinner can have dessert,if everyone finishes but the child (because they wont eat it) get evryone else desserts and say they wont get one until they finish.If after a long time they do not finish warn them there will be nothing else to eat untill next meal and then take the plate away from them.
Make everything small. Big portions must look huge to a small child. You can always give them more. Half small oranges, scoop out the insides, make orange jelly with the juice and a few cubes of orange jelly. When set cut in half like a wedge. Make tiny fairy cakes in sweetie cases and put a dolly mixture on top. Cut sandwiches with different biscuit cutters. Stars, teddy bears etc. Make tiny club sandwiches with two layers. Don't get stressed about it. If your child is running around all day they are getting enough to eat. Look at the big picture. What have they eaten over a week.
Let the children get involved in MAKING their own food. Chances are they'll eat it then.
Iced Lollies are a good way of getting fluids into small children who won't drink. Make them from fresh fruit juices with the children. Clean teeth afterwards though.
No juice or milk until after dinner - their tummies are the size of their fist, so a cup of juice fills them up pretty fast. Also, my 2 year old who is very independant laughs when we set aside a bite on his fork and say, "Don't eat that bite!" Gets him laughing and takes away the power struggle and gets him to try something new (and then he hopefully has more than just one bite!)
Try not to fuss too much, making a big deal out of food will negatively affect the child. I was a very fussy eater, I didn't like pizza, burgers, ham, cheese... you name it, I hated it!
Most of the time I was unfamiliar with them so I just didn't want to try it. Other times I just didn't like them.
As the children get older, let them make their own healthy food, let them come shopping with you and let them choose their own fruit and veg, and even keep them in their own 'Food Boxes' so they feel special and they'll be more than likely to eat them.
Eat your own dinner--he/she will learn by example. My friend's three year old still falls for the "if you don't eat it I will" line but also eliminate treats if he/she doesn't eat dinner--the promise of desert still motivates me to eat my veggies! :)
Never force them to eat otherwise they will do the opposite. I used to force my daughter to eat, but then i stopped and gradually she ate alone when she felt hungry. Now she asks for food when she REALLy wants.
If you have a friend with a child who is a 'good' eater, invite them round for meals. Often when a child sees another child eating without a fuss, they start to do the same.