Loss is one thing, but maintenance becomes so critical. You can fast for three weeks and lose weight. The idea is to maintain. You can only maintain through consistency of behavior. You have to monitor your food and exercise.
People dread exercise.
But research says you must be active to get a better body. Then there is the time bugaboo. People complain they are too busy to exercise. There is no way around it. Even with people who are physically challenged, there can be movement.