First of all, you must keep exercising every day. Secondly, eat healthy food, such as vegetables. If you really want to stay slim, you can't eat too much meat. Third, I'm afraid you won't believe it, but it's true-you must sleep for more than 8 hours every day, and you can't sleep too late.
If you do this, you will become thin and healthy. Isn't it that easy? Now let's have a try! Please believe me!