15 pounds. An average pregnancy weighs 20-25# at the end, so I reccomend 15-20# weight gain in obese women.
20 pounds. The upper limit of recommended weight gain for women who are obese was recently changed to 20 pounds.
Depends. Keeping weight gain undercontrol in an obese woman is safe when done properly and in the long run makes the pregnancy much safer for her and the baby. Eat a diet rich in fruits and vegetables, lean protein, low fat, hearty, unprocessed carbohyrdrates, etc. Frankly you can do weight watchers while pregnant. It is a sound, sensible way of eating.