Raise your hand if you have an advanced degree in biology, anatomy, nutrition, or medicine. No? Well then, I’ll do my best to take a very complicated process and make it as understandable as possible.

Over the last few years, I’ve asked a lot of people about metabolism, including my own doctor. Here’s the kind of typical responses I’ve gotten: “It’s kinda like how your body digests food,” or “It’s related to what you eat, and how fat you are” or “It’s how much fat your body burns.” Ummm, that’s a little like asking people about electricity, and hearing them say, “You know, it’s the thing that makes our lights and stuff work.”

You may already know I’m a very curious person. If I can’t find somebody to give me a reasonable answer to a question, I’ll spend a few minutes thinking about where my expensive Britannica Encyclopedias are, before remembering I sold the whole set at a garage sale in 1988 for $25. Realizing I lost a couple thousand dollars over that deal, I’ll then ask the “G” man, who always has around 1,453,879 possible answers. After reviewing maybe 7 of those, I’ll conclude that the internet is a great place for a lot of misleading information, like how to find and date a french actor in Paducah, Kentucky.

So let’s try an analogy: if you have a car with fuel in the gas tank, you can get in, start the engine, and drive somewhere. At a very basic level, the fuel in your gas tank gets sucked or pumped into the engine where it’s ignited, explodes, releases energy, and forces pistons to move. This happens quickly, in multiple (4, 6, or 8) cylinders with very precise timing. As the pistons move one after another, the crankshaft they are connected to rotates, spinning the flywheel at the end of the crankshaft, which is connected to the transmission. Then as the the internal parts of the transmission rotate, and the car is put into gear, the vehicle’s wheels turn, and off you go. Overall, there’s an energy conversion happening: chemical (gasoline) to mechanical (movement), via thousands of small explosions, reactions, and inter-connections. Clearly there’s a lot more to making a car move safely and efficiently, but two things are certain: good fuel, and a clean and well-conditioned engine is a must!

If our bodies were machines, like cars, metabolism would be everything happening inside: we consume food, the food is converted into fuel, the fuel gets distributed and is used (burned) by every cell in our bodies, the waste gets removed, and viola, we are alive! To be sure, human metabolism is very complex, but that’s OK; most of us don’t know how electricity works either. Metabolism is simply the set of biochemical processes that keeps our bodies going, whether we are awake or sleeping. And your metabolic rate is the rate at which your body uses the energy (fuel) you provide it, measured by the number of calories you burn, over a certain amount of time, usually one day. A little like your car’s MPG rating. Our total metabolic rate is made up of three main components:

1. Calories needed for basic bodily functions, such as breathing, making your heart pump and your blood circulate, maintaining body temperature, and making some of your systems (immune, endocrine, nervous, lymphatic, etc.) function. This basic level is your basal metabolic rate (BMR). In most people, this accounts for 50% to 60% of calories used each day.

2. Calories needed for eating, digesting, absorbing, and storing food. This is called the thermic effect of food (TEF). At this level you are actually using energy on a small scale to convert energy on a larger scale. This is about another 10% to 15% of calories used each day.

3. Calories you use for physical activities. Called activity-related energy expenditure (AREE), this accounts for the rest of the calories you burn, somewhere between 25% and 40% of calories used each day. Your metabolic rate increases to process what you eat and to provide the energy for the remaining systems, which gives you power to move. So if you are out walking or running, you’ll need to increase your calorie intake. But if you’re laying around the house, don’t do that.

But before we get to far here, I’d just like to know if you’ve ever noticed people are always looking for shortcuts. We want to get rich quick. Or we want to lose weight fast. Or we want to move up the corporate ladder in a hurry. Well here’s some advice: cut it out! It almost always ends badly. Do you remember the story of the tortoise and the hare? Slow and stead won the race, right?

Now back to metabolism. I imagine by now you are wondering a couple of things: (1) is there such a thing as having a sluggish metabolism, and if so, will it cause me to be overweight? And, (2) is there something I can do to “rev-up” my metabolism to lose weight? The answer to the questions are: indirectly, and not really. So here’s the scoop:

(1) Having a sluggish metabolism doesn’t make us fat: we get fat mostly because we keep pouring crummy and/or too much fuel into our amazing human machine, our body. That behavior screws up our bodily systems, and to a small degree, our metabolism, causing an unwanted result: excess weight and/or ill-health. When was the last time you put crummy fuel into your car? Never? Runs pretty nicely on the right fuel, doesn’t it?

(2) There really is no need to “rev-up” your metabolism. Forget about energy drinks, pills, potions, etc. All you need to do is provide the right fuel to your body, which will eventually get your metabolism working right, the way it was designed. You know, just like your car. However, there are a few things you can do while you’re working on improving your fuel (nutrition) program.

First, start loving yourself. Consider that your sex, age, hormone levels, mental health, body size and composition all affect your metabolic rate (basil metabolic rate). In addition, our thyroids, our pituitary glands, our hypothalamus, and our liver all support or hinder our metabolism. Women tend to have lower BMRs than men, and older people lower rates than younger. In part that’s because muscle burns more calories than fatty tissue, and as we age, we lose muscle mass. Climate also affects BMR, as does fever which increases BMR, while fasting and malnutrition reduce BMR. And of course there is a genetic component to our BMR, but that often isn’t as critical a factor as one might think.

Second, if you are overweight or obese, don’t feel like you are alone. Our culture is a mess, inundating us with advertisements to eat poorly then take medicine to feel better! While it’s easy to blame a sluggish BMR for obesity, that won’t fix anything. A sluggish BMR happens because we’re stuffed full of sugar, meat, oil, and other processed, high-density junk. But BMR is usually higher in overweight people, because they need more calories to fuel their larger bodies. And they tend to be more sedentary, however, and thus expend less energy through lack of activity.

Ironically, if you weigh 200 pounds and work hard to lose 50 pounds, your BMR will wind up lower than that of a person who has weighed 150 all along. Thus, it will be easier for you to gain your weight back.

You may also know about the “protein” promoters; people who swear by the Atkins and South Beach diets. But hang on a minute. It’s true that it takes your body more energy to process protein than carbs. But that doesn’t mean you’ll lose weight on a high-protein diet—it depends, ultimately, on how many calories you consume and how many you burn. Remember, if you consume (take in) more calories than you burn, you’ll gain weight. And, if you burn more calories than you consume, you’ll lose weight. Eating more protein has a small impact on your metabolic rate. However, your body needs protein for growth and repair, so make sure you don’t cut yourself short on protein.

Other practices that are “supposed” to increase metabolic rate include (1) eating frequent small meals instead of two or three larger ones, (2) green tea supplements, and (3) getting enough sleep. Unfortunately, the “grazing” theory has never proved out for weight loss—only a few studies have been completed, and no significant boost in metabolic rate has been proven. Green tea extract, often promoted as a weight-loss aid, might help in theory because of certain phytochemicals (including caffeine) in the tea, but studies have yielded inconsistent results, and any such effect is likely to be small and brief. Several studies have linked inadequate sleep with weight gain and, possibly, reduced metabolic rate, but the effect of sleep loss has not been directly measured. Obviously, if you’re exhausted from lack of sleep, you’re less likely to engage in physical activities.

So here’s the bottom line: there is no easy or cool trick for boosting your basal metabolic rate; your BMR doesn’t change much at all, unless your body mass changes. However, there is good news! If you start putting good fuel (meaning a mostly plant-strong, whole-food diet) into your amazing body, your body will begin working like it was designed to. Your your weight will begin to drop, your “sluggish” metabolism will change, your energy levels will climb, and your health will improve. If you have no idea where to begin, take a look at my previous blog posts “Forks over Knives” and Is Your Density Related to Your Destiny?

In addition, kick up your activity program. Although aerobic exercise such as brisk walking, running, biking, and swimming are good, they are short-term calorie burning activities. Much more valuable to your BMR is building or rebuilding muscle in your body. Strength training can increase BMR via a higher percentage of muscle mass in your body, which causes your body to burn calories round the clock, including while you sleep. A balanced workout should include both aerobic and strength-building activities, but if your schedule won’t permit both, opt for the strength training.

Finally, don’t forget to drink plenty of water – your body really needs water! Do you know what happens to a car engine if there isn’t enough water inside? Ask a mechanic. And fiber; you need fiber to keep your elimination system clean and moving well. Also check your pH and strive for a balanced or even slightly alkaline pH blood level. Lastly, do your best to get plenty of sleep; between 7 and 9 hours every day. Your body needs enough rest to heal, rejuvenate, grow muscle, repair tissue, and synthesize hormones.

Your metabolism works great, or at least will work great, as long as you are committed to putting good fuel into your body. You know, just like you do with your car.

To Your Health and Mine,

Dr. Hank