So after reading about calorie shifting, it says you have to determine your BMR so that you know how many total calories you eat for the week. How often do I have to recalculate my total calories and BMR? Every time I lose a pound, or maybe every 10 pounds? Only when I stop losing? Calculating my BMR right now, it says I need about 10,815 calories a week. How long do I eat that many calories for?