Yeah, because when you've busted your ass all week, and finally get two days to stop, the first thing you want to do (well, after you get done cutting grass and cleaning the house) is make a week's worth of meals.
I'm sorry, but I do take some level of exception to the idea that people are fat because they're lazy. Sure, that's true in some cases, maybe even most. But not all. Not by a longshot.