Sparkpeople takes into account a daily living multiplier to account for daily activities when calculating your BMR. Here's how they do it: www.sparkpeople.com/resource/calorie_calcu
If you are eating under 1200 calories, yes, you are undernourishing yourself. If you want to burn fat, but not lose weight, you need to focus not on calorie deficits, but strength training!
500 calorie deficits are necessary for overweight people to lose 1 lb per week; if they have enough to lose. If your goal is to lose fat, but not weight, you're creating too large a deficit for yourself.
Edited by: DRAGONCHILDE at: 7/8/2013 (14:10)