Hold on to your horses for a second! Yoga is followed to maintain a healthy lifestyle, so don't practice yoga like some generic exercise and drop it once you're lost weight. The long term effects and benefits of yoga are too many. In order to lose weight through yoga, you'll have to follow yoga every single day without fail. You should not perform the asanas (postures) in a random manner, as that will not help you. Seek the help of a trained expert and do it systematically, so that your damaged tissues and muscles are rectified and you infuse some freshness into your system.