It's almost impossible to lose weight by sitting, unless you basically don't eat. People can burn body fat only by consuming energy. You must know very well that the more you exercise, the more energy you need, and of course the more fat you consume. If you don't have time, walk as much as possible on the way to work (walk for half an hour), take fewer cars (if the journey is not far), eat 60% to 70% full dinner after work, and go out for a walk for half an hour to an hour after dinner. If you can, you can go to a health club to exercise after work or on weekends. You must stick to it.