They had a great article about how if you're trying to diet for weight loss you should not ever have a cheat meal, ever.  Their idea was that if you have that on the horizon then you only eat healthy as a way to get to the cheat meal, as opposed to eating healthy for literally every other benefit. Obviously when they say "never", I take it to mean however long it takes for the change to be permanent, but you know with heffalumps if you said no McDonalds for 3 years they'd have a countdown clock hanging on the wall.