Originally Posted by Off Road
People in prison camps don't stay the same weight. People who are sick don't stay the same weight. My wife, some friends, and many co-workers go on Weight Watchers with no increase in activity and lose weight. Nobody said anything about having to sit on the couch all day, but yes you could sit on the couch and lose weight if you were taking in less calories than your body functions were using up.
People that are sick usually lose muscle mass first due to the catabolism they bring in by not eating calories.
You would have to be in starvation mode to eat fewer calories than you expand by just sitting on the couch.