S.C.
Throw away the junk food. Seriously, just get rid of it! If it's in the house, you'll break down and give it to him. You'll think "At least he's eating SOMETHING." Am I right? ;) Trust me, you are not alone! My daughter has always been a small eater. She will gladly eat three bites of dinner, then wolf down five cookies. We had to just get rid of the junk all together. My husband still struggles with giving our daughter treats when she doesn't eat all of her food. We're much better now and she'll at least east MOST of what's given to her. Sit him down with a meal, if he doesn't eat it, he doesn't get anything till the next meal. You can also save his last meal and if he wants a snack, that's what he gets. That worked for us too. Start it now while he's young enough and he'll be a better eater in no time. Trying to break him of a junk food habit later in life will be MUCH harder. I'm not saying it will be all smiles and roses, chances are you'll have to deal with a few tantrums of epic proportion. Just remember "this too shall pass." Stick to your guns and THROW OUT THE JUNK! Good luck! :)