For years, products have been marketed with the promise of helping you burn more calories. But is there really anything you can do to increase the number of calories your body burns each day?
Well, yes and no, experts say. The truth seems to be that the No. 1 way to burn more calories is the old-fashioned way -- by moving more.
"Essentially, we know of no way to burn more calories or up our metabolism than to move more," says Barry M. Popkin, PhD, director of the Interdisciplinary Obesity Program at the University of North Carolina, Chapel Hill.
Still, research suggests that there may be a few other ways you can increase calorie burn. Here are eight possible ways to burn more calories and fight fat:
1. Exercise to Burn Calories
Christopher Wharton, PhD, a certified personal trainer and researcher with the Rudd Center for Food Policy and Obesity at Yale University, put it simply: "The more time spent exercising and the more vigorous the exercise, the more calories will be burned."
Indeed, obesity expert George Bray, MD, with the Pennington Biomedical Research Center in Baton Rouge, La., believes that taking a brisk walk every day is probably the single most important piece of advice for anyone wanting to burn more calories.
Obviously, when you exercise, your body burns calories to fuel your activity. But exercise is the gift that keeps on giving. That's because even after your workout has ended, your body is still burning more calories.
While it's hard to pinpoint just how long this effect lasts (it varies depending on body composition and level of training), "it's safe to say metabolic rate can be elevated with aerobic exercise for at least 24 hours," says Wharton.
If you want to prolong this calorie-burning effect, Wharton advises exercising for longer periods.
"Studies have shown that with increases in exercise time, the elevation in resting metabolic rate is prolonged," he says.
2. Do Strength Training to Build Muscle
When you exercise, you use muscle. This helps build muscle mass, and muscle tissue burns more calories -- even when you're at rest -- than body fat. According to Wharton, 10 pounds of muscle would burn 50 calories in a day spent at rest, while 10 pounds of fat would burn 20 calories.
"The most effective way to increase metabolism and burn more calories is by aerobic exercise and strength training. Both are important," Megan A. McCrory, PhD, a researcher with the School of Nutrition and Exercise Science at Bastyr University, says in an email interview.
Strength training becomes especially important as we get older, when our metabolisms tend to slow down. One way to stop this is to add some strength training to your workout at least a couple of times a week. The largest muscles (and therefore the largest calorie burners) are in the thighs, abdomen, chest, and arms.
3. Drink Caffeinated Green or Black Tea
Caffeine is a stimulant, and stimulants tend to increase the calories you burn. One likely reason is that they give you the short-term impression that you have more energy, which could mean you move more. Caffeine may also cause metabolic changes in the body that can result in more calories burned.
"Even older studies have suggested that 250 milligrams of caffeine consumed with a meal can increase the calories spent metabolizing the meal by 10%," says Jamie Pope, MS, RD, LDN, a nutrition lecturer at Vanderbilt University School of Nursing. Over time, this could be significant, Pope says in an email interview: "About 75 calories per day translates to over 2,100 calories in a monthâs time."
Over the past few years, some studies have hinted that green or black tea may have benefits beyond the caffeine they contain.
One study noted a reduction in food intake in rats that were given a polyphenol found in green tea. Another study, in humans, concluded green tea had heat-producing and calorie-burning properties beyond what can be explained by caffeine. When 31 healthy young men and women were given three servings of a beverage containing green tea catechins, caffeine, and calcium for three days, their 24-hour energy expenditure increased by 4.6%, according to the research from Lausanne University in Switzerland.
Drinking tea with meals may have another fat-fighting effect. Tea extract may interfere with the body's absorption of carbohydrate when consumed in the same meal, according to a study published in the September 2006 issue of the American Journal of Clinical Nutrition.
While all these possible effects are slight, there is yet another bonus to drinking tea. Having a zero-calorie cup of tea instead of a beverage with calories (like a soda) will certainly reduce the number of calories you take in.
4. Eat Smaller, More Frequent Meals
Every time you eat a meal or snack, your gastrointestinal tract turns on, so to speak, and starts digesting food and absorbing nutrients. It costs calories to fire up the human digestion machine, so it makes sense that the more small meals or snacks you eat through the day, the more calories you'd burn.
There isn't much solid evidence for this effect, McCrory notes in an email interview. But many experts believe that, compared to eating one or two very large meals, this is a more healthful way of eating anyway. And if it leads to even a few extra calories being burned, even better!
5. Don't Skip Breakfast
Evidence supporting a link between skipping breakfast and increased body weight is growing, according to a recent editorial in the Journal of the American Dietetic Association.
Some research has shown that when people skip breakfast, they tend to eat more calories by the end of the day. Other studies have suggested that skipping breakfast is associated with a higher body mass index in teens.
While we could use more research in this area, eating a healthy breakfast certainly makes sense as a lifestyle habit.
6. Eat Low-Fat Dairy
The calcium from low-fat dairy doesn't specifically help burn more calories, but it may do a couple of things to help discourage body fat. Results from a recent Danish study suggest that we might absorb fewer fat calories from a meal when we consume calcium from low-fat dairy.
In another recent study, eating more calcium-rich foods -- including low-fat dairy products -- appeared to be linked to lower amounts of belly fat, particularly in young adult white males.
7. Drink 8 Cups of Water a Day
"Just about everything you call on your body to do burns calories, including absorbing and utilizing water while maintaining fluid balance (sometimes by excreting excess)," says Pope.
Drinking almost eight cups of water (2 liters) may help burn nearly 100 extra calories a day, according to findings of a small study from Germany, notes Pope.
That may not sound like much, but it could add up to 700 calories a week or 2,800 calories a month. And that's by doing something we should do anyway to keep our intestines and kidneys happy, and to help keep us from confusing thirst with hunger. (Pope does add a caution not to overdo it; it is possible to drink dangerous amounts of water.)
Any type of movement requires energy, and fidgeting definitely qualifies as movement.
"Older studies suggest additional calories can be burned each day with fidgeting," says Pope.
One study even found that informal movement such as fidgeting may be more important than formal workouts in determining who is lean and who is obese.
Diet and exercise are good topics to discuss with your doctor. Before starting a new exercise regimen or supplementing your diet, it would be good to talk it over with your doctor. If you have certain medical conditions or are taking certain medications, there may be activities or dietary supplements that you should avoid.