I work 4 days a week, so I know this thread isn't really for me, but I can't agree with you enough. On work days it is so much easier to keep things under control. When I'm home, I eat out of boredom or because I'm getting something for the kids and I mindlessly nibble some myself.
At work, on the other hand, I can make my plan for the day and stick to it like glue. Knowing I have a plan and structure helps me to even avoid the cookies/doughnuts/pizza/whatever that people leave in the kitchen. Even now I can smell someone making popcorn in the kitchen, and I'm not even remotely tempted. But at home, I know I'd have a handful as I delivered the bowl to the kids.