Part of it, however, is PERSONAL. I know women who ate junk through their entire pregnancies, and didn't exercise ONCE, who gained 25 pounds during their pregnancy...and I know women who ate healthfully, exercised, and gained 80. You can strive to be as healthy as you can-and you should because it's better for you and the baby-but you can't really control your weight gain as much as people would like to think.
I, for instance, have gestational diabetes. For some women it isn't much of an issue, but for me-it causes big weight gain. I stayed on a particular diet during my pregnancies, and I exercised about 5-6 days a week up until I delivered my baby. I walked on the treadmill, did prenatal yoga, prenatal strength training dvds, AND taught belly dancing classes up until delivery. I gained about 55 pounds...and had a 9 pound 3 ounce preemie. He was a month early, and was my SMALLEST baby.
I did everything right, and still gained a lot of weight...you can't always control it.
