It’s easy to get into a health rut in winter. With holiday indulgences and fewer opportunities for outdoor activity, many of us add losing a few pounds to our lists of New Year’s resolutions. But winter doesn’t have to be a time of sluggishness and weight gain. By paying attention to our metabolism and the foods, herbs and lifestyle choices that affect it, we can keep our health and energy high through every season. Using a combination of the right diet and herbs, smart habits and exercise, we can invigorate our metabolisms and improve our health.
The 3 Components of Metabolism
The metabolism is our bodies’ natural process of converting what we eat and drink into energy—either to be burned right away or stored as fat. In general, the higher our metabolisms, the more calories we burn and the less fat we store. Three key components determine how many calories our bodies burn each day: our basal metabolic rate (BMR), the thermic effect of food and our physical activity level.
The basal metabolic rate, or BMR, is the measure of the number of calories our bodies use for basic functions such as breathing, circulating blood and repairing cells. It accounts for about 60 to 75 percent of the calories we burn on a daily basis and is influenced by a wide range of factors including body size and composition, gender and age. While we can’t change some of these variables, we can increase our BMRs through building and maintaining muscle tone. The more muscle our bodies have, the more calories we burn—even when we’re inactive.
The thermic effect of food, or thermogenesis, refers to the increase in metabolic rate caused by digesting, absorbing, transporting and storing food. It accounts for about 10 percent of the calories we burn each day, but maintaining the right combination of lean proteins, complex carbohydrates and healthy fats (as well as avoiding processed foods and eating on a regular schedule, as we’ll discuss later) can optimize the process and help manage weight.
Our daily physical activity—including aerobic exercise and weight training, as well as everyday movements such as running errands or doing chores—account for the rest of our daily calorie expenditure. Physical activity is the most variable and controllable component of metabolism. The more active you are, the more calories you burn.
Good Fuel: Metabolism-Boosting Foods
Some people go to great extremes to lose weight, eliminating entire food groups, eating large quantities of certain foods (grapefruit diet, anyone?) or drastically cutting calories. But extreme dieting can actually send signals to the body to go into “starvation mode,” making it more likely to burn muscle rather than fat for the protein it needs for daily functions. Reduced lean muscle mass, in turn, reduces your BMR, making it more difficult to lose weight. To keep our metabolisms humming, experts recommend women never dip below 1,200 calories a day.
To determine the optimum number of daily calories you need to maintain your ideal body weight, multiply your ideal weight by 12 if you are not very active or by 15 if you are active, recommends the University of Maryland Medical Center. To lose weight, we must create a calorie deficit, so aim to eat around 500 calories per day fewer than that number until you achieve your ideal weight, then increase your calories to the maintenance amount. Regardless of the number of calories you need, eating a sensible diet of small, nutrient-dense meals throughout the day can naturally optimize metabolism.
Finding balanced nutrition begins by eliminating refined grains, sugars and processed foods from our diets and replacing them with whole foods that challenge our metabolisms to work harder. Protein, for example, makes us feel full longer; helps build muscles; and has a high thermic effect—meaning it requires more energy to digest, leading to a temporary rise in metabolic rate. Incorporate lean protein sources such as chicken, fish, tofu or legumes into each meal. We should also include high-fiber complex carbohydrates such as brown rice, whole-grain bread and pasta, and quinoa, which break down slowly, provide steady blood sugar levels and are less likely to be stored as fat. And of course fruits and vegetables provide high levels of metabolism-boosting fiber, vitamins and minerals in few calories.
The timing and quantity of our meals can also affect our metabolisms. Eating a healthy breakfast early in the day helps shift our metabolisms into gear after the slow pace they run on while we sleep. Steel-cut oatmeal, high-quality yogurt and eggs are all excellent options that help prevent low energy and cravings later in the day. Eating smaller, more frequent meals throughout the day helps to stabilize blood-sugar levels and keep our metabolisms running smoothly. This is especially important to remember at dinnertime. Eating a large meal right before bed sends insulin levels soaring, overtaxing the digestive system and energizing us when we should be relaxing. It’s best to eat our last meal at least two to three hours before sleeping, and to avoid alcohol, caffeine and sugar in the evening.
Herbs and supplements can also boost your metabolism. Kelp, mustard seed, cayenne pepper, ginger, yerba mate and green tea all promote thermogenesis, helping the body burn food more effectively. Fish oil and flax seed supplements are excellent sources of omega-3 fatty acids, which some experts believe increases the production of leptin, a hormone that regulates satiety and appetite. A high-quality multivitamin also can help fill in any nutritional gaps (see “Resources” at the end of this article for more information).
Feel the Burn to Boost Your Metabolism
The right diet is one piece of the metabolism puzzle, but to maintain our weight, we must burn as many calories as we consume each day. This is where exercise—the most variable and controllable component of metabolism—comes in. While any type of exercise is good, a combination of aerobics and strength training is especially effective at boosting metabolism.
Aerobic exercise—whether walking, running, biking, swimming or any other activity that gets your heart rate going—is an efficient way to raise metabolic rates and burn calories. The Mayo Clinic recommends healthy adults aim for at least 150 minutes of moderate aerobic activity (or 75 minutes of vigorous aerobic activity) a week, but you may need to increase the time and intensity of your workouts to meet specific weight-loss goals. To get the most out of your workout, try alternating bursts of intense activity with intervals of lighter activity. This type of interval training burns more calories in less time, and the post-workout recovery forces our bodies to continue burning fat for energy long after we’re done.
Strength-training exercise, such as weight lifting, also burns calories; but more important, it builds and maintains muscle, which places higher demands on our metabolisms than fat. The more lean muscle we have, the higher our resting metabolic rates will be. To increase muscle mass, incorporate weight-bearing exercises into your fitness routine. A few sessions with a personal trainer can be very helpful if you don’t have any weight-lifting experience, but as a general guideline, challenge yourself with progressively heavier weights and more repetitions. Allow 48 hours for your muscles to recover and rebuild before you work the same set again, and always listen to your body. If something doesn’t feel right, stop immediately.
There’s no doubt that good nutrition and exercise can do wonders for our metabolisms, but when we’re stressed or sleep-deprived, we can’t fully reap the benefits. When levels of the fight-or-flight hormone cortisol stay high due to long-term stress, our blood sugar and blood pressure rise as well, which can lead to insulin resistance, slow metabolism and weight gain. People who produce high levels of cortisol in response to stress are more likely to store fat in their bellies—even if they are thin otherwise. They’re also less likely to get enough quality sleep, which can result in decreased levels of leptin, an appetite-suppressing hormone, and increased levels of ghrelin, a hormone that triggers hunger.
While we may not be able to totally eliminate stress, we can learn how to manage it. First, it’s crucial to get enough sleep—seven to nine hours a night for most adults. If you have trouble getting to sleep, try some relaxation techniques. For example, if your mind is racing, write down what’s bothering you so you can create a plan to fix it in the morning. Breathing exercises and meditation can also lower cortisol levels and silence nagging thoughts. Regular exercise can also help us deal with stress. Yoga, tai chi and simple stretching are great ways to release tension. When our minds are in balance, it’s easier for our bodies and our metabolisms to follow.
Additives: Hidden Culprit
Lately, scientists have begun to wonder if metabolism is affected by the chemicals we ingest. Over the past 50 years, obesity and Type 2 diabetes have skyrocketed. Many experts attribute this to increased caloric intake and reduced physical activity, but evidence leads researchers to wonder if that’s all there is to the obesity puzzle.
For example, obesity isn’t on the rise only in adults; the same phenomenon is observed in newborns and wildlife that lives near humans, neither of which has presumably changed caloric intake or physical activity. In addition, many Western European nations consume a similar number of calories as Americans, yet have obesity rates that hover around 15 percent, while American rates hit more than 30 percent. Europeans spend a significantly larger portion of their incomes on food, leading to theories that a diet of higher-quality, less-processed foods may account for lower obesity rates.
One group of food additives strongly suspected of influencing our weight is endocrine disruptors, a group of chemicals—notably bisphenol-A (BPA) and phthalates, among many others—that mimic estrogen in the body. Research finds that fetal and infant exposure to these chemicals may increase risks of obesity later in life.
In one study conducted at Tufts University, mice whose mothers were exposed to BPA throughout pregnancy showed increased weight in adulthood, despite having the same food intake and activity levels as others. The BPA-exposed mice also had disturbed insulin sensitivity, glucose balance and levels of the weight-regulating hormone leptin. In another experiment, EPA researchers found that pregnant mice exposed to the endocrine disruptor perfluorooctanoic acid (PFOA), commonly found in popcorn bags and fast-food liners, had offspring that were unusually small at birth, then obese later in life.
High-fructose corn syrup (HFCS) is another food additive suspected of wreaking havoc on our metabolic systems. While some scientists argue that our bodies metabolize HFCS in the same way as sugar, research has found evidence to the contrary.
In a study conducted at Princeton University, rats with access to HFCS gained significantly more weight than those with access to table sugar, even when overall caloric intake was the same. The rats that ate HFCS also gained unusual levels of body fat and experienced a rise in circulating blood fats called triglycerides. Another study by the Princeton Neuroscience Institute—the first animal study of the long-term effects of HFCS consumption—monitored weight gain in rats that consumed HFCS over a period of six months. Rats with access to HFCS gained 48 percent more weight than those eating just rat food and had significant increases in triglycerides.
Ready, Set, Burn! Natural Metabolism Boosters
Keep your metabolism churning with these simple tips from 100 Ways to Supercharge Your Metabolism by Cynthia Phillips, Shana Priwer and Pierre Manfroy.
Rise and Shine: Exercise in the morning to raise your metabolism for the entire day.
Quench Your Thirst: Drink a glass of water before meals. It is easy for our bodies to mistake thirst for hunger; staying fully hydrated will help you feel satisfied.
Catch Your Breath: Deeply inhale and exhale through your nose (so your chest and lower abdomen move with each breath) to increase oxygen levels in your bloodstream and burn more calories—especially during exercise.
Spice It Up: Add a dash of powdered cayenne or hot sauce to your food. Both contain capsaicin, which can increase the rate at which our bodies burn fat tissue.
Dig It: You don’t have to spend hours at the gym to rev up your metabolism. Actively weeding, watering, raking and planting can burn up to 350 calories an hour.
Avoid Toxins: Minimize your exposure to endocrine-disrupting chemicals such as phthalates, bisphenol-A and volatile organic compounds, which can disrupt hormone levels, and in turn, wreak havoc on your metabolism.
free iPhone app tracks daily consumption of calories and helps you set weight-loss goals
free app turns iPhone into a pedometer that measures steps, distance, workout time, calories burned and pace
100 Ways to Supercharge Your Metabolism
by Cynthia Phillips, Shana Priwer and Pierre Manfroy
Flip the Switch: Proven Strategies to Fuel Your Metabolism & Burn Fat 24 Hours a Day
by Robert K. Cooper
Master Your Metabolism: The All-Natural (All-Herbal) Way to Lose Weight
by Lewis Harrison
estimate the number of daily calories your body needs to maintain your current weight
Linus Pauling Institute
learn more about recommended dietary vitamins and supplements from a world-renowned micronutrient research center
USDA National Nutrient Database
find nutrient content (calories, vitamins, minerals and fats) for almost 8,000 foods in this searchable database
Ginevra Holtkamp is a freelance writer and photo stylist who stays healthy by eating well, walking and swimming.