Does not eat much

My 3 yo son usually eat chicken nuggets, chips, and popsicles all day.  We try to get him to try foods we're eating for dinner and he refuses.  Sometimes all he wants to eat is chips and popsicles.  The only time he does eat the dinner we eat is when we are having pizza or fish sticks.  He's always been in the 20% for his weight as have 2 of my other children.  The doctors have never really been concerned about his weight.  My question is, is he getting what he needs & when should be be concerned?  He does like certain fruits like apples and pears, but again he doesn't eat it much.  

[Renee Radenberg]

Some 'picky' eater have a very limited range of food. Recommend giving him a chewable children daily multi-vitamin due to his eating habits. The most important is to relax at meals. If he will not eat a certain food not eat too much, do not make a fuss over it. Let it go and enjoy the meal.