If you can get him to eat high quality food great. Don't make it a battle though, because you'll ultimately lose. The biggest thing I can recommend is quantity. 16y/o boys can put away copious amounts of food. Encourage him to eat for nutrition first, but don't deny him the treats he wants.
What I'm getting at is. If he wants "real pizza" let him have it on occasion. The battle is not worth the price in the long run. You won't win anyhow. Just my opinion, sometimes we take this lifestyle too literally when it comes to our kids.