Metabolism. You’ve heard the term before. People complain, “I’ve got a slow metabolism. I just can’t lose weight.” Diet gurus urge, “Get that sluggish metabolism moving!” They make it sound as easy as jumpstarting your car! But, what does the term really mean? And, more importantly, how does it affect your health and your ability to maintain a healthy weight?

For some, metabolic rate is the Holy Grail of weight loss. And, that interest can grow as we age. After all, most people put on some extra weight as they get older, and, at the same time, find it harder to shed excess pounds.

Unfortunately, there’s a lot of conflicting information about metabolism out there. Some of it is true. Some of it is speculative. Some of it is simply bunk. So, if you’re confused about the term, you’ve come to the right place. Think of this as your crash course on metabolism; what it is, what it means if you’re trying to lose weight, and what you can and cannot do to affect it.

Is the fault in our stars? Or in ourselves?

That paraphrased quote from Shakespeare defines the metabolism debate that has raged for years. Is your metabolism set by factors beyond your control, like genetics or body type? Or are you in charge of your own metabolism and how it affects you?

If a recent study published by Herman Pontzer, an evolutionary anthropologist with Duke University, is correct, the answer may be “neither.” Pontzer recently studied the metabolic rates of Hadza tribesmen in Tanzania. He found that the Hadza people, while fit and active, burned no more calories during the course of their day than the average, sedentary American, despite their genetic differences.

Pontzer claims, in a recent interview with AARP, that the average adult over the age of fifty “burns about 2,500 calories a day” regardless of how active they are. He states that when you exercise, your body conserves calories by simply drawing on those it has assigned to other functions like “inflammation and hormone production.”

When studies like these are published, it can be hard to know what’s true and what’s not. And, the controversy over metabolism is likely to rage on for years. But, for right now, you need some hard facts. So, instead of looking at what we don’t know, let’s take a look at what we do.

What is your metabolism?

It’s actually pretty simple. Think of your body as an engine. Food goes in; energy is produced. Your metabolism is all the chemical processes that drive that engine. These chemical processes regulate how your body breaks your food into component parts, uses those parts to release energy, or stores that energy for later use. If you imagine that engine of yours breaking down food, burning it for energy or storing it as fat, you can see how metabolism can play an important role in maintaining your ideal body weight. An efficient metabolism will give you more energy. An inefficient one will store more fat.

What affects your metabolism?

Your metabolic rate is determined by many factors, some of which are completely beyond your control. According to the Mayo Clinic, your body size, sex and age all affect you many calories your body burns on a daily basis. The bigger you are, the more muscle mass you have, and the more calories you burn, even when you’re at rest. Men, who usually have more muscle mass and less fat than women of the same age and weight, naturally burn more calories. Older people also have less muscle and more fat. That means they also have slower metabolic rates.

There are other factors that affect your basic metabolism. And, despite Professor Pontzer’s recent findings, it’s still believed that activity is one of them. After all, our active metabolism is quite different from our resting metabolic rate. Activity can include everything from getting out of bed in the morning and staggering out to the kitchen, to running that half marathon. Even the very process of eating burns up calories. This can account for as much as ten percent of the calories you consume in a given day.

What are metabolic disorders?

While most of us have a fairly average metabolism that functions in a fairly average way, there are diseases that can affect the metabolic processes in your body and how well they function. Some of these disorders are inherited, others, like diabetes, can develop later in life. The U.S. Library of Medicine defines metabolic disorders as an “abnormal chemical reaction” within your body that disrupts how your body processes and uses the different parts of your food, like proteins, fats and sugars.

Symptoms can include rapid, unexplained weight loss or gain, extreme fatigue and even sores that won’t heal. If you feel you may have a true metabolic disorder, don’t try to manage it on your own. Discuss your concerns with your healthcare provider.

Can you change your metabolism?

That is the hope, isn’t it? And advertisers try to bank on that hope. Every day you see flashy headlines claiming the newest way to speed up your metabolism and make weight loss easy and effortless. Specific supplements. Designer diets. Power drinks.

Fortunately, while most marketing claims turn out to be merely wishful thinking, some claims are backed up by science.

• Exercise is good for you – Whether it’s been proven to “speed up” your metabolism or not. A 2013 study published by the National Institutes of Health showed that sedentary patients who added just fifty minutes of walking into their routine three times a week over the course of twelve weeks, saw improved waist circumference, lower blood pressure, improved HDL cholesterol levels and better lung capacity.
• Drinking water speeds up your metabolism – At least briefly, and by as much as 30 percent, according to a report released by The Journal of Clinical Endocrinology and Metabolism. Given all of water’s other benefits, now there’s one more good reason to make sure you stay hydrated!
• Muscle mass speeds your metabolism, long term – While exercise alone may not speed your metabolic rate, the muscles you grow do. A study published by the NIH showed an increase in resting metabolic rates of at least seven percent in participants who practiced a strength training routine. Significantly, this increase was found in older participants at the same rate as in the younger ones.
• Some foods really can “supercharge” your metabolic rate – Well, “supercharge” may be a bit of an exaggeration, but certain foods have been found to speed up your metabolism and increase the number of calories you burn. According to the International Journal of Obesity, some everyday foods have a thermogenic effect, stimulating your metabolism and helping prevent “a positive energy balance and obesity.” These foods include green tea, coffee and capsaicin-containing foods such as chili peppers and jalapeños.

While the jury may still be out concerning just what our metabolism are up to and how much control we have over them, for now, it can’t hurt to add some – or all! – of these simple steps to your health routine.