Nickname for the Atkin's diet, a diet based upon eating large amounts of meat and disgusting fat, but not being able to eat rice or bread. People who are on this diet are probably going to die of heart failure later in their lives.
Linda: I'm such a pig- I had a piece of bread yesterday. That's it no more carbs...let's go eat a pound of bacon now.
Jesse: Dude, Fatkin's sucks.