Gaining

I suppose you could stuff, but you'd feel fuller sooner due to the special cargo on board. also keep in mind the gestational diabetes, which leads to larger babies and premature birth (i think).

Aside from the 'can you' issues that everyone else mentioned....there is 'should you.'

At the very least, you should be very careful with what food you were stuffing with. Giving yourself crazy blood sugar spikes is rough on your body, and when you are pregnant it is rough on the baby as well. Nobody is perfect and babies are pretty resilient, but probably best not to partake in most extreme types of behavior while pregnant.