Your body uses energy no matter what you’re doing. Even if you stayed in bed all day, you’d burn calories. The number of calories your body would use in a 24-hour period, even if you did absolutely nothing, is called your Basal Metabolic Rate. In other words, your basal metabolic rate is the average number of calories your body needs daily just to stay alive. It’s the energy used for basic functions, like breathing and a beating heart. An average number for American women is about 2000-2100 calories; for men it’s about 2700-2900.
You can get a rough estimate of your basal metabolic rate by multiplying your body weight times ten. Different types of tissue in your body contribute different amounts to your metabolic rate. Lean muscle burns more calories than fat. As a result, more accurate estimates of your basal metabolic rate will take your body composition into account. There are a variety of calculators online to help you do this.
Some factors that influence your metabolism are unchangeable:
* Gender. Men burn calories more quickly than women, mostly because they have more lean muscle tissue.
*Age. Your metabolism slows down as you age, again, mostly due to a loss of muscle mass.
* Heredity. Your metabolic rate is due to some extent on your genetic makeup.
* Thyroid disorders. Hyperthyroid (an overactive thyroid) and hypothyroid (an underactive thyroid) disorders affect a small percentage of the populations. Both of these disorders can impact your metabolic rate.
Luckily, there are also several things you can change to improve your basal metabolic rate:
* Weight. The more you weigh, the higher your metabolic rate. While this may seem counterintuitive, remember that it simply takes more energy to power a larger body than a smaller one. Don’t forget, though, that muscle tissue is denser than fat, so it will weigh more than an equal volume of fat.
* Body composition. Again, muscle mass contributes significantly more to your basal metabolic rate than fat does. Muscles actually move, which burns energy. Fat just sits there. A pound of fat uses only about two calories each day to sustain itself, while a pound of muscle needs about six. As a result, the more lean muscle mass you have, the higher your metabolism will be, even when you’re at rest.
* Diet. Severe calorie restriction can work to lower your basal metabolic rate. Your body will enter “starvation mode” and begin to conserve energy, effectively lowering your metabolism. Eating small meals more frequently throughout the day keeps your metabolism running at a consistently higher level. In addition, your body uses more energy to digest protein than it does to digest carbohydrates or fat, so make sure you’re getting an adequate supply of protein. Healthy sources include lean meats, tofu, beans, nuts, eggs, and dairy products.
* Water. Your body can’t process calories if it’s dehydrated, so your metabolic rate will decrease. Make sure to drink about eight glasses of water every day.
* Fidgeting. Every extra move you make burns a few calories. Even fidgeting contributes to the overall total.
While some of factors that contribute to your basal metabolic rate are beyond your control, there are a number of changes you can make to improve it!