What does "junk-food-scoffing masses" mean? [closed]
The phrase means "the large numbers of people who scoff junk food". In this case to scoff means to eat greedily or quickly.
"scoffing" is not a modifier to "masses", rather it belongs to the "junk food" part of the sentence.
"Junk food scoffing", here, scoffing means to eat rapidly (the type where you swallow it without barely chewing).
Rewriting the sentence, "the group of people who greedily eat junk food"