Just as your mind longs for balance, your body strives for a steady state. Too cold? You shiver and warm up. Too hot? You sweat. Believe it or not, this natural inclination applies to weight, too. Your body aims to maintain an optimal level of fat -- not too much and not too little. But look around and you'll notice that a lot of bodies -- perhaps even your own -- are out of balance. About 60 percent of Americans are obese or overweight, and many more struggle with a few stubborn extra pounds and low energy. The traditional weight-loss route, however, doesn't always work: You cut back on food, wrestle with appetite and cravings, but your weight doesn't budge. Or it goes down a little only to inch up again.
This back-and-forth makes many people wonder: Is my willpower to blame, an inability to choose steamed kale over French fries? Or is this just the way my body is? Some experts say the problem lies elsewhere: a metabolism imbalance. We think of this energy-regulation system as set in stone, blaming our thick thighs on our slow metabolism or coveting a slender friend's speedy metabolism. But it's more complex than that, says Mark Hyman, M.D., author of "UltraMetabolism." This intricate system can be dragged down by bad food choices, too much stress, and not enough exercise.
"Your lifestyle patterns can get you stuck," says Hyman, "but there are ways to get unstuck. We have a huge capacity to transform our bodies." He and like-minded doctors analyze a patient's biochemistry to see how lifestyle and diet affect her body's ability to turn food into energy.
Once you understand your body's inherent intelligence, you can give it the tools to do what it does best. "The goal isn't to speed up the metabolism," says Leo Galland, M.D., author of "The Fat Resistance Diet." "It's to normalize it." It's not difficult, say both doctors. Key lifestyle adjustments can help get any body get back on track -- and stay there.
The following pages will help you understand your metabolism and beat it at its own game.
By Kathryn C. Kukula
Your Metabolism: Best-Case Scenario
Knowledge is power, as the saying goes, and metabolism knowledge starts with a quick lesson in biology -- your own. Metabolism, the process by which your body changes one substance into another, governs how quickly and efficiently your body turns food into energy. As Hyman explains it, the effects are profound: metabolism does nothing less than determine health or illness.
Under optimal conditions, metabolism is an elegant, self-regulating process. Suppose, for instance, you eat an apple. Even as you look at the apple and start to salivate, metabolic chemicals begin to flow. As you digest the apple, sugars from your intestine enter your bloodstream. Sensing this rise in blood sugar, your pancreas secretes insulin, which shuttles the sugars through cell walls and,
via the brain, speeds up metabolism. Within your cells, the sugars are converted to acids, which combine with hundreds of mitrochondria in your cells to create energy. All the while, hormones released by your thyroid have been telling your cells how quickly to use the apple's energy. Any sugar that's not absorbed by your cells goes to your liver -- and is stored as fat there or elsewhere in the body.
Body fat, it turns out, has its own "intelligence." Over the past decade, researchers have discovered that fat cells release hormones. Among the most important is leptin, which works to lower appetite. If everything works as it should, the more body fat you have, the more leptin you produce. "As a result, your basal metabolic rate goes up," says Galland, and you lose fat. Lower levels of body fat, on the other hand, produce less leptin, causing your metabolic rate to drop, so that you don't lose too much weight.
In other words, your body's chemistry lab constantly balances your weight, appetite, and energy levels for metabolic balance. At least, that's "the normal situation," says Galland. "But factors that we have created are interfering with this process."
What Gums Up the Works
In order for leptin and other metabolism-regulating hormones to do their work, your cells must be able to receive them, and that's where modern life comes in. To understand how the process goes awry, think of your body as a computer. "Your genetic makeup is like software," says Hyman. "You're inputting requests all the time." The primary data, he explains, is food.
Throughout most of history, this "data" has been whole foods like grains, vegetables, fruit, and natural meat. While certain individuals may have intolerances to some of these foods, in general they supply our bodies with the instructions they need to function properly. As Galland explains it, whole foods contain messages that "tell your body what to do with calories." The antioxidants in leafy greens or blueberries, for example, help rev up your mitochondria, turning calories into energy.
Many processed foods, on the other hand, contain chemically derived ingredients our bodies don't know how to "read," such as high-fructose corn syrup, trans fats, MSG, or artificial colors. "One of the biggest problems of the modern American diet is that we've moved away from traditional herbs and spices and replaced them with artificial flavors and sweeteners," says Galland. "It's created a metabolic disaster." Overly processed foods are essentially "blank" calories without messages, he says.
Coupled with chronic stress and low levels of exercise (also relatively new factors in the human experience), this "blank" food contributes to chronic inï¬‚ammation, which "blocks your body's ability to use calories in a normal way." Here's how: Your body releases chemicals to counter the inï¬‚ammation. But these natural anti-inflammatories use the same "entry points" as leptin -- that all-important weight-regulating hormone. With your cell receptors clogged with anti-inflammatories, your body becomes "leptin-resistant." It never gets the message to turn up metabolism and turn down appetite. Inflammation wreaks havoc in other ways, too: It shuts down the mitochondria in your cells, suppresses the thyroid gland, and contributes to insulin resistance, a precursor to diabetes and heart disease. The perils of modern life don't stop at Twinkies. Toxic chemicals in the water we drink and the air we breathe also do a number on metabolism: They contribute to inflammation while damaging our mitochondria, the "energy factories" in our cells. In one study of a group of obese people trying to lose weight, the amount of weight lost was directly related to the level of toxic organochlorines (a class of chemicals that includes dioxins) circulating in their blood; those with the lowest levels of toxins lost the most weight, says Galland.
Making Quality Changes
Is there any way to reverse this curse? Hyman and Galland say yes -- it's a matter of changing the "data" that go into your body. Like other doctors, they recommend eating sensible portions and getting regular exercise to maintain a healthy weight. But they take the metabolism tune-up further: It's not just the quantity of food and exercise that matters, they say, but the quality.
A sound diet is "nutrient-dense," meaning it has a high ratio of nutrients -- including fiber -- to calories, with plenty of anti-inflammatory foods and herbs. (See Healthy Metabolism Tools.)
In terms of exercise, altering the pattern of your workout -- not simply exercising more -- can make a big difference in how your body uses oxygen and calories. In one study, subjects who alternated high-intensity bursts with longer recovery periods -- called interval training-- lost nine more pounds than those who simply increased the amount of exercise they did.
Finally, reducing stress and enabling your body to release toxins set the stage for metabolism balance, they say. Practices like yoga and sweat-inducing regimens such as saunas can help you achieve these goals. The results build as your metabolism rebalances, both Hyman and Galland have found. "You'll see changes in a week," says Hyman. "Sugar cravings and fatigue are reduced pretty quickly." Besides losing weight, these doctors say, you may find that you aren't as hungry, your mood improves, your energy stays steady throughout the day, and you can think more clearly. And when the body gets clear messages, the potential for healthy weight and balanced, authentic energy expands -- letting you explore new limits in your life.
Is Your Body in Balance?
Mark Hyman , M.D., recommends several blood tests for his patients to help determine how their metabolism is functioning; several of these are listed below. Talk to your doctor about whether they may be appropriate for you.
+ Thyroid Tests measure levels of the thyroid hormones T3 and T4 and thyroid-stimulating hormone (TSH) in the bloodstream. A high level of TSH indicates low thyroid functioning, or hypothyroidism, while low levels can indicate an overactive thyroid. Thyroid hormones interact with all other hormones in the body to stimulate metabolism.
+ C-Reactive Protein Tests measure the amount of inflammation in the body. The higher the CRP levels, the higher the amount of inflammation. Doctors also use CRP to measure a person's risk of heart disease, arthritis, and other chronic lifestyle diseases caused by inflammation.
+ Diabetes and Pre-Diabetes Tests, including a fasting sugar test as well as insulin- and glucose-tolerance tests, screen for diabetes, metabolic syndrome, and insulin resistance.
+ HDL Cholesterol and Triglycerides Tests can also reveal how well your body is using insulin. Low HDL combined with high triglycerides indicate insulin resistance.
+ Cardiobetabolic Stress Tests show how well the body can turn oxygen into energy in the cells' mitochondria.