Do you know how to cook? That might stave off some of the weight.
I also work a sedentary job and don't commute, which stinks. However, since I have my home office, I rarely eat out for lunch as I would rather prefer to spend my break time sleeping (thank you CFS), so I just end up eating leftovers or cooking something quickly.
Anyway, McDonalds...i have a craving, like, every week. I think it's pure oil and salt because those are two of my favorite ingredients.
When I visited my parents last weekend, I took the train on Friday and I had to switch at the Philly station. Without even thinking about it, I ran to the counter and ordered McNuggets and a small fries. Only after I arrived at my final stop did I realize it was Friday, and I had eaten vegan sausage and some fruit for breakfast. Clearly McDonalds has some sort of power over me. SAH GOOD.