If you are really responsible for your body, then rejecting high-calorie junk food and moderate exercise is absolutely king. Even you don't have to go on a diet deliberately, just keep your usual appetite. You know what makes you fat is those high-calorie foods such as cakes and potato chips! (Although it's really hard to quit! )
Cecilia Cheung still has something to say: She has accumulated more than 50 hours of exercise a week to lose weight after childbirth! Exercise is really a good thing, it is very helpful for your shaping, and it can prevent your body from being loose after losing weight.
How ugly!
I hope these digressions can help you. On the way to losing weight, you must stick to it!