Maybe you’d like to lose a few pounds or maintain the weight you’ve lost without its creeping back on. You’d like to eat a little more without fear of gaining.
And if you’re in your late 30s (or older), quite possibly you sense that your metabolism is slower now than it was when you were, say, 25.
Some people will shrug their shoulders and accept that as a consequence of “getting older.” It doesn’t have to be.
You can do something about it, and in this two-part article I’ll tell you how. (Watch for part two next week!)
I’m going to explain what metabolism means, how it works, and–here’s the important bit–how to crank it up. You won’t need pills, supplements, or anything crazy to do it. So let’s begin.
What is metabolism?
We talk about people who have a “fast metabolism” or a “slow metabolism.” But what does the word really mean?
We can define it as the energy cost of living: the daily requirements of “running” your body.
It’s like driving a car. If you want to go somewhere, your car has to do mechanical work to get you there. To perform that work, your car’s engine needs an energy source: gasoline.
Your body also has work to do: all the processes involved in sustaining life. You’ve got a heart that beats, lungs that breathe, skeletal muscles that move, and so on.
A Volkswagen Beetle doesn’t need a lot of gas to run. A Ferrari 612 Scaglietti does: people buy one for performance and status, not fuel economy.
Increasing your metabolism is like gradually transforming your Volkswagen into a Ferrari: a vehicle that needs more energy to do its work.
Your body’s daily need for fuel–your metabolic rate–is measured in calories.
If you supply all the body’s energy needs through your daily diet, you maintain weight. Take in too many calories, and you store the excess as fat.
And if the body’s energy costs aren’t being met–because you’re consuming fewer calories or burning more calories through exercise (or both)–the shortfall has to be made up.
If you’re in an energy deficit but not starving to death, your body will do one of two things to get the energy it needs:
- burn fat or
- break down muscle.
In part two I’ll explain why this second possibility is so disastrous.
Two kinds of energy costs and how to increase them
Basal metabolic rate
To build a faster metabolism–one that runs more like a sports car than an economy model–we have to consider two kinds of energy costs. Our goal is to increase both of them.
The first is basal metabolic rate, or BMR: the number of calories your body needs just to exist.
BMR covers all of the involuntary processes (breathing, pumping blood, etc.) that go on every minute you’re alive, even if you’re lying in bed and not lifting a finger.
Surprisingly, BMR represents most of most people’s total daily energy requirement. If you’re a sedentary person who hardly moves, your BMR makes up more than 80 percent of your caloric need. If you exercise vigorously five or six days a week, BMR still accounts for nearly 60 percent of your caloric requirement.
The point: BMR is a big chunk of the energy equation.
You might think your BMR is set and unchangeable. It isn’t.
True, you can’t do anything about the amount of energy your liver, kidneys, lungs, etc. need to do their job.
What you can change is the amount of energy required by your muscle tissue, and I don’t mean by burning calories through exercise.
I’m talking about building more muscle, more metabolically active lean tissue, in order to increase your body’s energy needs all the time.
A person with more muscle burns more calories through BMR, every minute of the day, whether she’s sleeping or awake, motionless or active.
Probably you’ve noticed that most men can eat a lot more than most women, and when they diet, they lose fat more quickly. This is true largely because pound for pound, they have more muscle tissue and thus greater energy requirements. (Hardly seems fair.)
The takeaway: every pound of muscle you gain increases your metabolic rate–gives you a faster metabolism. Every pound you lose decreases your energy needs.
In part two of this article, I’ll give you real numbers, indicating how much of a difference muscle can make in your daily caloric requirement.
I’ll also address questions and fears you might have about the idea of gaining muscle. (Hint: You’ll look more gorgeous. You will not “look like a man.”)
The energy cost of activity
BMR does not tell the whole story. To get the big picture, we have to consider the second daily energy cost: the number of calories required for voluntary activity.
This includes all the actions that use your skeletal muscles: sitting up straight, standing, walking, and otherwise moving or stabilizing any part of your body–including engaging in deliberate exercise.
Everybody knows that exercise burns calories and that high-intensity movement (for example, running) burns more calories per minute than low-intensity movement (a gentle stroll). To burn more calories through exercise, we continue longer or work harder.
If you’re trying to lose fat, increasing voluntary movement is one of the most important strategies. It not only burns calories but also helps maintain your calorie-burning muscle tissue, according to the “use it or lose it” principle.
But you don’t have time to engage in designated exercise all day long.
Fortunately, “exercise” is not your only strategy for increasing voluntary movement and calorie burn. It’s astonishing how many more calories you can burn by simply standing and walking around more.
A 2005 study conducted by the Mayo Clinic found that on average, lean people stood or walked 152 minutes more each day more than obese people in similar jobs. The obese subjects sat 164 minutes more than their skinnier peers.
Dr. James Levine, the lead researcher, found that the lean people burned as many as 350 extra calories a day through fidgeting, changing posture, standing, and walking–what he called “non-exercise activity thermogenesis,” or NEAT.
NEAT alone can make a huge difference in your calorie burn!
Now let’s consider your total energy (caloric) need per day. To figure it out, you calculate your BMR, then add the energy cost of movement of all kinds. (Part two of this article explains how to calculate both BMR and calories burned through movement.)
The result is your “total daily energy expenditure,” or TDEE.
That number represents your metabolic rate–the sum total of the energy cost of living in your body each day.
If you’ve noticed that your metabolism seems to have “slowed” as you’ve gotten older, you’re probably right. You probably do burn fewer calories than before, for two reasons:
- If you’ve been sedentary or done very little exercise, you’ve lost muscle mass. The average person loses about 5 percent of her muscle tissue per decade after age 35. As muscle is lost, BMR decreases.
- If you exercise and move less than you did when you were younger–when you may have been running around after toddlers, playing softball, doing a more physical job, and so on–you’re burning less fuel through voluntary activity.
It’s a vicious cycle: you exercise less, you lose muscle, and the energy needs for both your BMR and your voluntary activity go down.
But you can change it.
In part two I’ll explain “the magic of muscle” and how it not only greatly improves metabolism but also gives you a better-looking body.
I’ll discuss how to determine your energy needs, why eating more protein means burning more calories, and how to prevent “starvation mode” while dieting.
This last point is especially crucial because incorrect dieting actually damages your metabolism and decreases your calorie burn, making it more likely that you’ll regain the weight.