I also eat 1200-1300 calories a day. Most days, I do an hour of cardio, so my net is under 800. I don't feel weak or dizzy, nor am I hungry all the time. I'm on the short side, too, so I think 1200 is fine for me. I've lost an average of 2 pounds a week for 4 months so it's working. Weight loss is a big "Your mileage may vary" situation.