If you keep you house stocked, it doesn't take much effort at all....especially if you are baking. The oven is doing all of the work.It's hard not to especially if you work a real job.
You have to eat something and a lot of the time you don't have the energy to cook a full meal.
Especially if you work out.
Also, going straight home to cook in comparison to going to a place to wait in line/drive-thru, the time spent almost evens out.