This is the point in a young wipper snapper's life when his skinny but untoned body starts to show the wear and tear of a decreasing metabolism. Love handles grow; nipples droop; two pack slouches into a blob. All together this is the most unattractive form of fat because he isn't fat enough to be cute.
You may notice that all the personal pronouns are masculine - this type of fat is not possible for females as they just become chubby.
Nick: Beach it?
Alex: Nah...
Nick: Man, come on.. Babes!
Alex: I can't man, not looking so hot...
Nick: What you mean, looking the same to me?
Alex: Nope, I'm drooping all over... I'm rocking skinny flub!