The way is that you climb the stairs, with 2 steps less in your stomach and 3 steps less in your thighs. Go back and forth for an hour, and don't eat after 1: 30 in the afternoon and at night. That's what I do, if I'm pregnant! I do 30 sit-ups, and the effect will hurt in one month.
Remember to drink soybean milk, rice and rape at noon. You'd better not eat at night.
If you are really hungry, drink more water.