The way I see it, with pizzas' high fat and carb content, low protein and fibre content -
its gotta be the worst fast food out there, unless you can think of an alternative? I think maybe 'chips' would vie for the worst junk food title, however, very few people have chips on their own. Pizza on the other hand can be eaten on its own, with HUGE amounts of cheese dripping through the crust. (I hope I'm not making people's mouth water
)
I wouldnt doubt that for a second.
Is he a heavy pizza eater? If so, Im guessing he isnt lean and is holding quite a lot of fat on him. Strong as an ox though. Thats one thing eating pizza will make you (if eaten with other nutrients), given its high calorific content, you can ensure that you hold onto any mass gains.
To be strong: eat loads (pizza included), ensure good protein supplies, train regularly and sleep well.
To be lean and strong: diet becomes very very important and pizza would become a big no-no.