it is impossible to lose 20 pounds without proper diet and excercise within one month. But i do know of a way to lose at least 3 to 5 pounds in a month or maybe more. Try to eat 2 slices of plain enriched white or wholemeal bread and a glass of low fat milk (about 200ml) for breakfast. then have a really light lunch like lots of soup and less solids and a proper dinner. No snacking in between your meals and 30 minutes of excercise everyday including jumping around with music (real high), sit-ups, running on the spot (lifting your thigh real high too), hula-hooping and increase your excercise time gradually (like 5 mins more) day by day. try to play your fav. music while doing all this excercises because it keeps you motivated and makes it more enjoyable. for stomach toning, do as many hula-hoopings or sit-ups as possible. i do this everyday and lost quite a few pounds (and got some abs). but juz remember to consume less calories and fat and do more activities.