Cheating on his diet, that is.
Derek Hough ain't no cheater cheater!
What he is, is a super hunky, super fit guy who needs to eat a very healthy diet to maintain his physique.
But no one is perfect, everyone screws up now and again, even Derek!
Besides, a little screw up every once in a while isn't the end of the world, as long as you get right back on track!
So when is it hardest for Derek to not cheat on his diet??
Check out the video (above) to find out!