This is just a phrase, rather than a sentence. Junk food - fast food (from McDonalds, KFC, Burger King and similar, basically food you can buy and eat quickly, but usually unhealthy) Scoffing - in this context eating messily (the main image that comes to mind is just stuffing it in your face without shame or care) Masses - everyone that isn't the speaker and those of the speaker's ilk (it's a typically demeaning label for anyone that the speaker generally doesn't like) Hope this helps.

I think "scoffing" is wrong here. Are you sure it isn't "scarfing"? Scarfing is a common slang term for eating a lot of food quickly, and it fits the tone of the sentence. In this case, "masses" refers to a large percentage of average people, not necessarily lower classes.