Hooray for minus 1 lb

Its only been a few days but I've lost 1 lb already. I'm using sparkpeople to track calories and exercise and there is a report on there for your daily calorie differential. It takes into account how many calories you burn just being (BMR), plus calories burned in exercise and calories eaten. The whole idea behind weight loss is that calories burned has to be greater than calories taken in. So lets do some math......since one pound of fat is 3,500 calories and I want to lose 2lb per week, my goal is to create a 1,000 calorie differential each day. When dieting the rule is to never eat less than 1,200 calories or your body will think its starving. My range set by spark people is 1,500-1,800. My BMR is about 2,300. So if I don't get any exercise but only eat 1,300 calories I still have a 1,000 differential. But that's hard to do, its easier to eat more calories and go for a walk to even it out. So far its only been 4 days but I've met my goal of a 1,000 differential, usually eating 1,600 calories and burning an additional 400-500 through exercise. Today I weighed myself to see if the scale would prove my math accurate. Yep, I lost one pound. Its a good start. However, realistically I don't think I can keep up the 1,000 differential everyday without feeling deprived, hungry and end up pigging out. So I'm giving myself a little slack one day a week if I need to.