Myths About Metabolism

In the topsy-turvy drama of dieting, exercise and blood-sugar control, an individual’s metabolism takes center stage.

Metabolism ultimately comes down to a person’s ability to convert food and drinks into energy, and efficiently burn calories — while the body is active and at rest.

Along the way, many myths have been created: Do skinny people have a faster metabolism? Will eating late-night meals slow down your metabolism? How about this one: You can’t change the metabolism with which you were born?

“We tend to define people by body type, large or skinny, but there isn’t necessarily a correlation between body size and metabolism,” says Maryanne Samuel, D.O., an internist with the Baptist Health Medical Group.  “Body type has to do more with body composition: muscle versus fat.”

Metabolism refers to the biochemical process that occurs within any living organism, including humans. Nutrients through the foods and drinks we take in, supply energy (calories) and provide the necessary chemicals that the body itself cannot synthesize.

The number of calories your body uses to carry out its basic functions is known as your “basal metabolic rate” or BMR — which most people refer to as simply metabolism. Several factors determine your individual basal metabolic rate, including body size and composition, gender and age.

Your BMR accounts for about 70 percent of calories burned every day. But two other factors determine the amount of calories burned: (1) The process of digesting and absorbing food and (2) physical activity, including exercise.

Here are the biggest myths about metabolism or BMR:

1.) You can’t change your metabolism. (False)

The Facts: Regular exercise not only burns calories from the immediate activity itself, but also from the calories that will be used later — while the body is resting. All this will ultimately increase BMR.

So you don’t have to live with slow metabolism.

For every pound of muscle, the body burns about 35 calories a day, while for every pound of fat, it burns just two calories per day.

Increased muscles and muscle density will result in your body burning more calories, which in turn will raise the body’s BMR. So, strength-building exercises can help you raise your BMR. Aerobic activity, such as running, cycling or exercise classes, also help the body burn calories more efficiently.

“Metabolism is about energy in and energy out — finding that balance,” Dr. Samuel says. “Many patients don’t understand that you can alter your metabolism. Muscle is more metabolically active than fat. Ruling out any underlying health issues, the more lean muscle you have, the higher the metabolism.”

2.) Metabolism is the same for men or women. (False)

Men usually have a higher BMR because they generally have more lean muscle than women. This means that they burn more calories at rest than do women. Muscle mass is the body’s top calorie-burner. On average, men have nearly 10 percent higher BMR than women.

But many women are in better physical shape than men who don’t exercise. And some women may have a higher BMR because they perform weight-training exercises relative to male contemporaries who are sedentary. So while men may have an edge over women when it comes to metabolism, women can increase their BMR to match or exceed some men who are less disciplined when it comes to diet and exercise.

3.) Skinnier individuals have a faster metabolism. (Not necessarily)

Just about everyone knows someone who is thin and appears to eat whatever they want without gaining weight. They must have a faster metabolism, right? Possibly. But this is not always the case. Remember, higher muscle density is the best calorie burner. Thin people may be able to maintain a healthy weight through proper nutrition and exercise, but larger individuals may have more muscle mass and a higher BMR.

When comparing two individuals of similar weight, the more muscular person will generally have the faster metabolism. This point serves as a reminder that any exercise program should include strength training.

4.) Eating Smaller, More Frequent Meals Will Boost Your Metabolism? (Mostly False)

The most important factors in any diet are the quantity and quality of the food you consume. Every individual should eat a healthy diet that best fits his or her schedule. Some people prefer frequent, small meals throughout the day to avoid cravings or a “starvation mode.” Diabetics or people with poor blood sugar control — or “prediabetics” — benefit from eating in moderation on a regular schedule to avoid big drops or spikes in blood sugar levels.

In contrast, some people eat one large meal a day. This may lead to craving unhealthy snacks the rest of the time if you skip breakfast or eat a lighter lunch. In the end, however, what counts is the total number of calories consumed and the quality of the meals.  Avoid overly processed foods and focus on whole fruits, vegetables, lean meats and whole grains, experts says.

5.) Eating Late at Night Is Bad for Your Metabolism (Mostly False)

This myth says that if you eat late, you can’t burn those calories efficiently while sleeping. Though your metabolism slows down while you sleep, metabolism never stops working entirely. If you get hungry late at night, you should eat something — but make it something healthy and not high in sugar or carb-heavy. Your metabolism will naturally slow down after eight hours or so of sleeping. But it will pick up again when eating breakfast and when you start expending energy in the morning hours.

“These misconceptions are handed down over generations,” says Dr. Samuel. “People sometimes create cause-and-effect relationships: ‘I’m eating late at night, and that’s why I’m gaining weight.’ It’s important to be transparent about eating and lifestyle habits that need to change. Keep a food journal, for example. Start an exercise program. Take the stairs more often. Remember, you can change your metabolism.”