Basal Metabolic Rate
Your Basal Metabolic Rate (BMR) is the energy it takes to keep your involuntary body processes going.
About 60% of the calories you consume are used for such things as breathing, maintaining body temperature, manufacturing hormones and keeping your heart beating. It takes roughly 10% of calories per pound of body weight to meet those needs. A 120lb (8st 8lbs) woman, for example, will need 10 x 120, or 1,200, calories each day just to function.
Factors that can affect BMR
- For every decade beyond the growth years (about age 20) your calorific needs drop about 2%. A 30-year-old may need 1,200 minus (2% x 1,200) = 1,176. Calculate your age percentage and deduct your daily calorific need.
- Your body build, which is largely inherited, is another factor. Tall, thin types burn more calories because they have a larger surface area, and more calories are burned to maintain normal body temperature.
- Muscle burns calories, even at rest, and men on average have more muscle than women, so they need more calories.
How to influence your BMR
- Exercise - depending on the length and intensity of your exercise, you can boost your BMR for several hours afterwards.
- Severe dieting can reduce your BMR as your body attempts to conserve calories. This is a survival tactic and not a good idea for a healthy lifestyle.
- Muscle mass burns more calories, even at rest, than fat. The greater your ratio of lean to fat, the more calories you will burn.
- Calorific needs - about 30% of your calories fuel any physical activity you do, from scratching your nose to running a marathon. Of course, the marathon will take significantly more than an additional 30%.
Weight loss
Obviously, it's easier for those lucky souls with a higher basic metabolic rate to lose weight more quickly, and to keep it off. But you can't blame your genes for everything! As discussed above, anyone can improve their BMR and enjoy the benefits of a more efficient metabolism.