A good diet would be one with whole grains, fish, and fresh fruits and vegetables. I usually recommend at least 60 grams of protein. Also, get at least 3 liters of water a day. That's the biggest one. I wouldn't recommend any special diets or fad diets. I mean, what I usually have women do it write up a three day diet diary. When I look over it, I can pretty much tell if she's short on calorie intake or something like that. Generally what I see working the best is when women avoid processed foods. They should be eating whole grains and fresh fruits instead. Avoid white flours and white sugars. It's amazing how quickly women recover and things like that. Diet makes a big difference, and a lot of the complications that arise in pregnancy can be avoided with a good diet and enough water. The number of calories a woman needs depends on her weight, her age, and her activity level. It can vary.