if you want to lose 20 pounds of fat in 30 days, you must know that it wont be easy.... You will have to really on your losing 20 pounds strategy.
My video http://www.youtube.com/watch?v=YIi46hh6id4 will explain you in detail a little bit about what women should do in order to drop 20 pounds easier. And it all comes down to calories and burning down those calories as soon as possible.
In order to lose 20 pounds you must burn off about 60000 calories, in order to lose 20 pounds in a month, you must burn down 2000 calories each day.
The video is all about weight loss, and you should really watch it and learn the steps of losing 20 pounds in 30 days.