He was talking all about himself and his movies when Larry asked about his emaciated look.
McConaughey told him how he lost 15 pounds for an upcoming role where he plays an AIDS patient.
He looks really thin already and he still apparently has to lose another 15 pounds.
He said by the time he's ready for the role, he will not look healthy.
Check out the video (above) to see the crazy skinny McConaughey talk about his crazy diet.