Mark is extremely active and eats only 2800 calories/day or so. Dr. Kurt Harris says he eats only 1800 calories/day and neither of them have run into many problems. I don't think calories as just this 'number' on a piece of paper matter. Your appetite wont let you down. Appetite is a very complex evolutionary adaption. It won't let you waste muscle or let you starve. Unless you have anorexia in the medical sense (which can be caused by drugs, severe dieting, or other metabolic/hormonal disrupting substances), don't sweat it. 1200 calories does not sound like anorexic levels.