Why do teenage boys need to masticate so much?

I remember that being used to embarrass a 15yo boy in my class. He was trying to eat something surreptitiously at the back of the class. "Why are you masticating at the back of my class?" Horrified looks from half the class and laughter from those with a good vocabulary.

They wouldn't get away with that nowadays, I think.

Did you spell that correctly?

Teenage boys can really pack it away. Must be growth

Is it all of them, or just the chewish ones?

Masticate?

Let me guess.... an American teenager living the American dream?