I'm a diabetic and am not doing the 500 calories, but a modified version of 800 calories a day with 500 calories of it in protein.  In 14 days, I have lost 8 lbs.  I'm happy with that.  I am also trying to keepmy carb intake at 50 or less per day.  I am NOT taking the appetitie suppressants or monitoring ketosis.  I did not want to take those risks associated with that.  I am getting a B12 shot once each week.  I think this appears to be a g reat program with a doctor on staff and nurses too.  I like the counseling and personal touch.  I am wondering what the weight loss research shows...