Ok to have a cheat day?

Yep, totally agree that when you've dieted down at some point your body will start to stubbornly hang on to its fat reserves. You have to trick it into thinking it isn't a "lean time" to keep making progress. 3 days on diet calories and 1-2 on just above maintenance seems to work for most people. As stated above its as easy as eating like you normally do and throwing in a couple cheat meals.

 I love the way Lyle Mcdonald breaks down cheat meals and re-feeds based on categories of bf%.