I can understand where New Yorker is coming from. But I think his plan of having a cheat meal once a week is especially risky for someone who has recently lost a lot of weight. Remember, a diet is a way of life, not something you go on temporarily, and then discontinue.
But New Yorker is right in terms of some fat being necessary for the metabolism during dietary plateaus. That should not be an excuse to stop all your good work. According to nutritionist Ann Lousie Gittelman, author of the book "Eat Fat, Lose Weight" you need good Omega 3 essentially fatty acids. These can be found in fish like salmon and tuna, as well as flaxseeds, flaxseed oil, and Evening Primrose Oil.
So I still say, eat a good healthy filling meal before you go to your Thanksgiving party. Then maybe try a tiny bit of whatever looks good. But that's it.