There's no getting around this fundamental truth: You can't have weight-loss success unless your calories burned are more than your calories in. Leslie Bonci, M.P.H., R.D., a sports nutritionist at the University of Pittsburgh Medical Center, recommends these formulas for figuring out how many calories your nutrition plan should include. Everyone is different, but it will give you a basic idea.
Lazy-Day Calorie Goal
(use on days when you're taking it easy/not exercising):
A. Your weight, in pounds: ____ B. A x 15 = _____ C. B - 500 = _____
Busy-Day Calorie Goal
(use on days when you're active/exercising):
A. Your weight, in pounds: ____ B. A x 18 = ____ C. B - 500 = ____