Taken from link above me:
Now, keep in mind that if you eat everything in site with no restrain, chances are that any benefit you may gain from the cheat meal will be lost since it may just take a whole week to burn off all of the calories consumed. In this case, fat loss results would be compromised. Therefore, still use common sense and self control in order to make your cheat meal work.
As you can see, it's not suggested to go out and eat a big mac, fries, and a coke in order to help spike your metabolism. The thing they are probably suggesting is to just mix it up, and not eat the same thing day in and day out.
Also, unless your diet is super, super strict, I guarantee you don't need to worry about one cheat meal in order to spike your metabolism.