Your BMRis the most important factor because it determines your body overall Metabolic Rate that will help you to create a weight loss program that fits your needs. Your Basal Metabolic Rate (BMR) determines how many daily calories your body requires to maintain your current weight, and it will also tell you how many calories to cut to lose weight. It uses multiple factors, including; height, weight, age, gender & activity level to determine your daily calorie intake to maintain your current weight.