it probably isn't the best idea to have so little protien in his diet, but kids sometimes do have issues about eating animals. replace the meat on his plate with tofu or quorn based product and he'll be okay. Any symptoms of anemia and go to a doctor!
I use Metagenics Pro Gain Protein Powder for my son in the morning for breakfast and add frozen fruit as the ice. http://www.metagenics.com/products/detail.asp?pid=189
If your son will eat eggs then don't worry about meat protein for now. Do you think he would notice if you mixed tiny pieces of chopped meat into cheese pasta, or something like that, that you could hide it in? If he does and refuses to eat it, give up hiding meat in his meals. Don't want him to start distrusting all his food!
Stay away from soy protein. Damages the gut and endocrine glands. My son is proof of this.
Don't worry too much about getting more meat into him. He might like Organic hot dogs. At the moment, this is the only meat my son will eat for some reason.