Without doing any exercises ,we can loose weight but it takes time as it becomes difficult to put a deficit of calories only by diet. One pound of fat consists of 3500 calories which means that we need to put a deficit of 500 calories per day by diet which is really unhealthy so its better to do atleast exercises 4/week to burn calories. You can start up with any sports you like .for e.g. volley ball, basket ball or any simple badminton of 40 min will be really a good workout and calorie burner. Even dancing your steps makes your body to burn calories. So who not you try these activities which are as worth as exercising for same time.