meth flab 

(noun) the saggy, drooping flesh that hangs from a person's body caused by rapid weight loss due to prolonged use of methamphetamine; particularly that of a previously overweight and/or morbidly obese individual

(sounds very similar to 'meth lab' when used in conversation)

"I wonder how long it took her to build up that meth flab." or "That meth flab destroyed her life."

meth flab by Flabstinence November 14, 2013