- 5 Things You Need to Know About Your Metabolism
- 1. Your Metabolism is More Than One Thing
- 2. Your Metabolism Adapts
- 3. Your NEAT is More Important Than You Probably Think
- 4. Your Metabolism Doesn’t “Break”
- 5. Your Resting Metabolic Rate Isn’t Super Useful For Weight Loss
- The Wrap Up
- What You Need To Know About Your Metabolism For Weight Loss
- What is metabolism?
- Do people have slow and fast metabolisms?
- Can you change the speed of your metabolism day to day?
- So if you want to lose weight, eating more protein can help?
- Does exercise raise your metabolic rate in the hours afterwards – the so-called afterburner effect?
- What approach to diet and exercise would you recommend for weight loss?
- 5 Things to Know About Your Metabolism, and How to Harness It
- Some parts of your metabolism are beyond your control
- Your muscles are in charge
- A lack of protein can slow your metabolism
- Dieting is the enemy
- Your metabolism s sleep
- Everything You Need to Know About Your Metabolism to Lose Weight
- What is metabolism?
- What bodily functions are fueled by the metabolism?
- What determines my metabolism's speed?
- What health conditions affectmy metabolism?
- How does my weight affect my metabolism?
- Does what and how I eat affect my metabolic rate?
- How does exercise affect my metabolism?
- What about exercise “afterburn”—doesn’t that help?!
- How to Measure Resting Metabolic Rate
- What a dietitian wants you to know about boosting your metabolism
5 Things You Need to Know About Your Metabolism
We often hear people say, “I have a slow metabolism” or “they just have a fast metabolism,” and we all nod our head in agreement. But do we understand what that means?
What is your metabolism? Can it be fast or slow? Does having a slow metabolism make you more inclined to gain weight? Does your metabolism really “break” when you diet?
These are the questions we are going to provide some clarity on in this article.
1. Your Metabolism is More Than One Thing
We often refer to our metabolism as a singular thing, it is this black box or small engine that stuff goes into and then comes . But the truth is, our metabolism is a collection of many things. In reality, our metabolism is the sum of all the metabolic processes in our body.
One of the most straightforward ways to understand your metabolism is to refer to it as your total energy expenditure. This means that your metabolism is the cumulation of all the energy your body expends to function. We will refer to this is our total daily energy expenditure (TDEE).
This TDEE can be further broken down into three main categories:
- resting metabolism (what most of us call our metabolism)
- the energy it takes to process the food you eat
- physical activity (more on that in a bit)
Your resting metabolism is the sum of all the metabolic processes that are required for you to live. This means your cells use energy to do things breathe, think, pump blood, etc. This represents about 60-70% of your TDEE.
The next piece is what we call the thermic effect of food (TEF). This is simply the energy it requires to extract the energy you get from your food. This is a relatively small amount of energy and represents about 10% of your TDEE.
The last piece that makes up your TDEE is your physical activity, meaning the amount of movement you do throughout the day. This is often broken down into two separate categories: physical activity that is from structured exercise (we call this exercise activity thermogenesis) and physical activity from non-structured exercise (we call this non-exercise activity thermogenesis).
2. Your Metabolism Adapts
Most of us think of our metabolism as this static thing that we don’t have control over. But it turns out; this isn’t the case.
First, you just learned that it is more than one thing. It is a collection of many different aspects of your body and its functions. Also, you learned that you have some control over at least parts of it.
Second, your metabolism is quite “adaptable.” It will adjust what you do in your daily life. Let me explain these two ideas with a few examples.
In one of the more interesting studies of the 1990s, scientists tested to see what happens to people when they increase or decrease their calories (1). They found that when you increase people’s calories, something very interesting happens: they start to burn more calories.
Primarily, they increase their non-exercise physical activity; they started moving around more.
Their resting metabolic rate also increased very slightly, with some of that coming from an increased thermic effect of food, but some of it also comes from having an increased body mass.
The same thing happened when they decreased their calories, but in the opposite direction. When people decreased their calorie intake, their physical activity decreased, as did their thermic effect of food and their resting metabolism from reduced body mass.
In short, their metabolisms adapted to the scenario their body was being exposed to.
3. Your NEAT is More Important Than You Probably Think
While our resting metabolism makes up the most significant part of our metabolism, it doesn’t change as much as people think it does. It also doesn’t play the most prominent role in weight loss or weight gain. Most studies that examine resting metabolic rate find that it does not predict weight gain or weight loss at all.
Outside of your resting metabolism, your non-exercise activity thermogenesis (NEAT) is the most essential aspect of your metabolism. Conveniently, it is also the most controllable.
One study found that a person’s NEAT was almost single-handedly the thing that determined why some people who “overeat” gain a lot of weight, and why other people do not (2).
Furthermore, two studies that followed the contestants of the weight loss television show The Biggest Loser found that their physical activity, including their NEAT, was the most significant predictor of who gained back the weight they lost from the show and who did not (3,4).
4. Your Metabolism Doesn’t “Break”
There is a meme that exists that people can have a broken metabolism that causes them to gain weight. Fortunately, there is no evidence to suggest that metabolisms can become “broken.”
Sure, your metabolism can decrease when you lose weight by carrying less body weight, moving around less, and having a lower thermic effect of food. Your metabolism can also decrease if you have significant hormonal issues, such as hypothyroidism. But your metabolism is not something that “breaks”; it naturally adapts to the stimuli you give it.
5. Your Resting Metabolic Rate Isn’t Super Useful For Weight Loss
There are many ways to measure resting metabolic rate, some more accurate than others. However, the accuracy of these tests is not overly critical because a person’s resting metabolic rate is not an overly useful measure for many reasons.
First, we can’t manipulate the resting metabolic rate to a meaningful degree through diet or exercise. Second, when we look at most research, resting metabolism doesn’t appear to matter very much for weight loss (5).
Your food intake and your NEAT are far more critical for weight loss efforts than your resting metabolic rate.
The Wrap Up
We often think about our metabolism as one thing. In reality, it is the full collection of all the energy-producing and energy-consuming processes that occur in our body. It is made up of our resting metabolism, the energy it takes to process our food, and our physical activity.
Your metabolism adapts to calorie increases and decreases, with a large part of the adaptation coming from changes in physical activity. While metabolisms can decrease, they do not “break.
” Lastly, lower resting metabolisms do not appear to be predictive of weight gain and by themselves are not overly helpful measures for most people.
If you're interested in learning more about energy balance and metabolism, become an NASM Certified Nutrition Coach. There is an entire chapter dedicated to these topics.
What You Need To Know About Your Metabolism For Weight Loss
“I can eat whatever I want – I have a fast metabolism.” The chances are you have heard that from someone in your life and the chances are that you d them a lot less after you heard them say it. Unfortunately, you can’t even lay a scientific smackdown on them, because there is quite possibly some truth to what they say.
“Different individuals have different daily resting energy expenditures. It depends on a variety of things,” says Michael Gleeson, emeritus professor of exercise biochemistry in the School of Sport, Exercise and Health Sciences at Loughborough University.
Gleeson is the author of Eat, Move, Sleep, Repeat, a book that grounds its advice about diet and exercise in science.
“I got sick and tired of reading books by people who are not really experts,” says Gleeson. “They don’t actually look at the scientific literature, and find out what has been shown to work and what hasn’t. If you go to the science you can find the answers. If you just make it up for yourself why should anyone take notice of it?”
Metabolism is an important part of the picture when you’re managing your weight, so we spoke to Gleeson to find out more about it.
What is metabolism?
It’s essentially the sum of all the chemical reactions that are going on in your body. Its main role is to provide you with the energy you need for your cells to survive, to perform their basic functions, and then to do additional things exercise where we need extra energy
Another role is building new molecules from small ones. We get all our essential nutrients – the main ones are protein, carbohydrate and fat – from the things we eat and drink in our diet. These get digested down to small molecules in the gut so we can absorb them.
Then those are taken up into the tissue and usually reassembled into different molecules we need to function normally. Some of the excess stuff that we take in is stored, either as glycogen if it’s carbohydrate, or as fat.
That’s our long-term energy store we can use when we need it in periods of starvation.
From building muscle to producing neurotransmitters for the brain and supplying our muscles with energy – metabolism covers all of these things. If we think about the body as a series of organs and tissues that perform various physiological functions. All of these ultimately are underpinned by the metabolism.
Do people have slow and fast metabolisms?
Yes, the individual metabolic rate varies between people. It depends on a variety of things, primarily body size – the bigger you are the greater your resting energy expenditure is going to be, because you have a larger overall tissue mass that are metabolising all the time. It also depends on age, to a degree, and sex.
There are individual genetic differences as well. Some people are essentially more efficient at storing energy and becoming overweight when food is readily available or overconsumed, whereas some people can eat somewhat more than others and still not get fat. That’s probably down to the fact that their resting metabolic rate is a little bit higher.
It can also be influenced by things hormones, particularly your thyroid hormone. If you’re a person with hypothyroidism and don’t produce as much of the hormone thyroxine, your resting metabolic rate tends to be lower than other people.
Can you change the speed of your metabolism day to day?
It changes transiently [for short periods]. We all have a certain basal metabolic rate, or energy expenditure – the rate at which you expend energy or how many calories per hour you’re burning throughout the day.
If you’re resting and your muscles are relaxed, then your metabolic rate is the lowest it’s going to be.
When you’re sitting at a desk you’re using postural muscles to keep you upright, and that expends a little bit of energy.
Then what and when we eat, and the composition of the food we eat, also affects our resting metabolism to a degree. When you consume, digest and absorb a meal, those nutrients in the meal then have to be stored.
Digestion and absorption can be energy-requiring processes, but more energy is expended in storing your energy. This produces a temporary increase in your metabolic rate, which we call the thermic effect of feeding.
A more scientific term is dietary-induced thermogenesis.
Essentially this can increase your resting metabolic rate up to about a third more than normal. This is during the first few hours after you’ve consumed a meal, and it’s different depending on the composition of your meal. Protein has a considerably higher thermic effect than either fat or carbohydrate.
When you have a meal that’s predominantly protein then around about 20-30% of the energy in that protein will be dissipated as heat because it’s increasing your resting metabolic rate. For carbohydrate the value is nearer to 5-10% and for fat it’s even smaller, somewhere in the order of 3-5%.
So the composition of what you eat for your breakfast or any meal will affect your metabolic rate differently, but all will increase it to a degree.
So if you want to lose weight, eating more protein can help?
That’s one of the reasons why having a relatively high-protein diet is probably best for effective long-term weight loss. The higher thermic effect of feeding means fewer of the calories you’re taking in are being converted into carbohydrate or being stored as fat.
There’s other reasons as well, because if you have a high-protein diet and you’re also doing some exercise, that’s good for building muscle. When you’re dieting, if you’re not on a high-protein diet, you’re ly to be losing some muscle as well as excess body fat. With a high-protein diet plus some resistance exercise, you actually maintain your muscle mass when you’re dieting.
If you maintain your muscle mass, you help to prevent what would otherwise happen, which is a 10-15% fall in your basal metabolic rate as you adapt to the diet.
Does exercise raise your metabolic rate in the hours afterwards – the so-called afterburner effect?
I think rather too much is made of this.
Some people say if you do HIIT sessions you’ll get a bigger elevation of your resting metabolic rate and it’ll last for ten to 12 hours afterwards, but generally the studies that have actually measured people’s metabolic rates in respiration chambers after bouts of exercise have shown this effect on weight loss is not really significant – certainly not compared with the amount of energy you expend during the exercise itself.
If you do a five-mile run, say, you’ll expend about 500-600 calories. Even if that run then produced a 10% increase in your resting metabolic rate over the next ten hours, you’re only looking at an extra expenditure of 60 calories or so.
What approach to diet and exercise would you recommend for weight loss?
Exercise should be of moderate intensity – running, cycling, swimming are all great – and relatively prolonged if you have the time. Doing about an hour of that will burn around 500 calories or so.
Combine that with reducing your dietary energy intake by about 500 calories per day. If you’re doing that you’re generating a 1,000-calorie deficit every day. Do that five days a week and you’re losing 5,000 calories.
With that you can lose over 1-2 pounds [around ½-1kg] of body fat per week.
Don’t cut your protein intake – you can even increase your protein intake above normal – but cut down on fat and carbohydrate.
I’m not an advocate of cutting out fat or carbohydrate altogether because you end up with an extreme diet and you don’t need to do that. Just cut down food intake by 500 calories a day, and do it with a combination of reducing fat and carbohydrate.
Still maintain a balanced diet so you’re getting all the other essential nutrients, and make sure you’re getting more than enough protein.
Eat, Move, Sleep, Repeat is published by Meyer & Meyer Sport and is available from the end of January
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5 Things to Know About Your Metabolism, and How to Harness It
Your metabolism is a complex system. It determines how quickly and efficiently your body burns calories and how much you can eat in a day without putting on weight.
Scientists are still gaining new insight into the factors that make your metabolism run.
But they know for sure that becoming a healthier, stronger woman can fire yours up—prolonging good health, improving mood, slowing the effects of aging, and maybe even helping you lose some weight along the way.
Experts share the latest findings, plus what you need to know to make all that good stuff happen.
RELATED: 7 Easy Ways to Kick Your Sluggish Metabolism Up a Notch
Some parts of your metabolism are beyond your control
Although many of us talk about “metabolism” as if it’s a single bodily process, there are actually three types, each of which expends energy (or calories) at a different rate. Your resting metabolic rate determines the amount of energy your organs use to stay functional when you’re just sitting around.
It makes up the largest piece of the metabolism pie (around 60 to 75 percent) on a regular workday with minimal activity, and there’s very little you can do about it. In fact, contrary to what you may have heard, thin people don’t have faster resting metabolic rates.
“The bigger you are—regardless of whether that weight comes from muscle or fat—the higher your resting metabolic rate will be,” says Martica Heaner, PhD, adjunct associate professor of nutrition at Hunter College in New York City.
Your active metabolism—which accounts for about 10 to 15 percent of the calories you burn in a day—dictates the energy you use up when you’re walking, running, exercising, even fidgeting (for some people). This is the type you have more control over, to some degree, since the more you move, the more calories you burn.
Finally, there’s diet-induced thermogenesis—the energy your body uses to consume and digest food. Yep, you get a bonus burn—8 to 12 percent of your daily calorie use—for eating!
TRY THIS TRICK: Believe it or not, spicy food and green tea can fire up diet-induced thermogenesis a bit. So brew some tea or pour a little hot sauce on dinner.
“You’ll get a teeny increase in your metabolic rate—we’re talking maybe a bump of 1 percent for an hour.
But these little changes add up over time,” says exercise physiologist Polly de Mille, clinical director of the Tisch Sports Performance Center at the Hospital for Special Surgery in New York City.
RELATED: How to Figure Out Exactly How Many Calories You Need to Lose Weight, According to a Nutritionist
Your muscles are in charge
A pound of muscle burns seven to 10 calories a day, while a pound of fat burns just two or three. We all lose muscle as we age, starting in our 20s, and as it vanishes, so does our calorie-burning power. “By your 70s, your resting metabolism may be 15 percent slower than it was in your 20s,” says de Mille.
“That’s 15 percent less food you can eat without gaining weight.” While building new muscle can help counteract this trend, it’s even more important to engage the muscle you already have, says Wayne L. Westcott, PhD, professor of exercise science at Quincy College in Quincy, Massachusetts.
Every time you challenge your muscles by strength training, they go through a breakdown-and-repair process, or remodeling. This means you burn calories while working out and continue to burn them after you put the weights away.
Keep up the practice, and you’ll increase the speed of your resting metabolism, even if your muscles stay about the same size.
TRY THIS TRICK: Do two or three 20-minute sessions of resistance training (12 to 20 sets of exercises) each week. In three months, your resting metabolism will be about 6 percent faster.
When you exercise, focus on major muscle groups. And don’t shy away from heavy weights. Start with one that’s about half as heavy as the largest weight you can lift.
As you become more proficient, switch to weights that are 60 to 75 percent of your maximum lift.
RELATED: Keto vs. Mediterranean: Which Diet Is Really Better for You?
A lack of protein can slow your metabolism
If you’re not already on the protein bandwagon, get on board. Although the USDA suggests consuming 5 ounces of a protein source per day as part of a 1,600-calorie diet, many experts say that recommendation is conservative or even on the low side, particularly for healthy adults over 50.
Your body needs amino acids—the building blocks of protein—to stay functional. “If you don’t eat a diet rich enough in them, your body’s forced to tap your muscles, which have a great reservoir,” says Wayne W. Campbell, PhD, professor of nutrition science at Purdue University in West Lafayette, Indiana.
When you lose valuable muscle, your resting metabolism pays the price.
TRY THIS TRICK: Make sure you’re putting protein in every meal and snack—starting the day with 15 grams (about two eggs) is a great idea. And don’t overlook whey, one of two proteins found in milk. It’s rich in the amino acids muscles thirst for and can aid recovery after workouts.
Dieting is the enemy
Any weight-loss diet—yes, even one that seems sensible—will leave your metabolism slower than it was when you weighed more. That’s partly because each time you shed pounds, you lose fat and muscle, but when you ditch your diet and regain weight, the pounds come back as fat.
And since smaller people have slower metabolisms than bigger people, you’ll have to eat even fewer calories than you did at the start of your diet to maintain your new weight.
More annoying news: The part of your brain that manages your metabolism cares little about whether you ever fit back into your favorite jeans, and cares very much about whether you have the energy you need to survive.
Try to cheat your body the calories it’s come to rely on, and it will immediately start robbing your muscles of fuel and directing that energy to your vital organs—causing your metabolism to dip lower.
TRY THIS TRICK: If your goal is to lose a significant amount of weight, take it slow. “It’s best to lose about 10 percent of your body weight, maintain that weight for three to six months, then lose more if you desire,” says Laura J. Kruskall, PhD, director of the UNLV Dietetic Internship & Nutrition Center.
“This gives your body time to adjust to physiological adaptations, a slower metabolism, and gives you time to learn healthy weight-maintenance behaviors.” Also, never eat fewer calories than your resting metabolism requires. The easiest way to determine that magic number: Take your body weight in pounds and multiply by 10.
Your metabolism s sleep
A single night of sleep deprivation can alter your metabolism and trigger weight gain, according to recent research from Uppsala University in Sweden. Lack of sleep tends to slow people’s metabolism, in part because that’s when your body repairs itself, which burns calories, says de Mille.
TRY THIS TRICK: Debating between an extra hour of sleep or working out? Do both! If you sleep in and then squeeze in 10 minute bouts of strength training throughout your day, you’ll give your metabolism an optimal shot at burning calories.
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Everything You Need to Know About Your Metabolism to Lose Weight
Chances are you have blamed some part of your body’s functioning on its metabolism. Common complaints, to name a few, include calling it “slow” and pegging it as the cause of weight gain.
It has even been simplified to the old adage: Calories in, calories out. But it isn’t that easy.
It's why WW asked experts to tackle the most common questions about metabolism to give you the big picture on what’s going on.
What is metabolism?
“Metabolism is the way we process foods and nutrients and convert them into energy. That’s what people think about when they think about metabolic rate—the rate at which we convert the foods we eat into energy,” says Scott Summers, PhD, chair of the department of nutrition & integrative physiology at the University of Utah School of Medicine.
When you eat, your body either uses the nutrients as fuel for activities, such as exercise, or stores them as heat—in the form of energy or fat.
What bodily functions are fueled by the metabolism?
While exercise certainly burns calories, there are other body processes that play a much bigger role in converting calories into energy. Here’s the breakdown:
- About 70 percent of all the calories you burn are due to your basal metabolic rate. It’s the energy needed to keep your body functioning while at rest. “That’s just the energy it takes to be alive. That’s the energy it takes to run you—keep your heart beating, mechanical stuff breathing in and out, digestion,” says Douglas White, PhD, associate professor in the department of nutrition, dietetics, & hospitality management at Auburn University.The basal metabolic rate is theoretical, since measuring it requires complete inactivity, White says. Resting metabolic rate, or RMR, is the closest approximation to a basal metabolic rate and what researchers use to study what affects metabolism. (See below: Measure Your Resting Metabolic Rate.)
- Physical activity burns 20 to 25 percent of the total calories you expend. Your activity level and intensity affect that percentage. If you’re a professional athlete, that percentage may be even higher. But activity doesn’t just mean exercise, White says, but includes any movement. “Just walking upstairs, just standing up, that’s going to burn some calories,” he says.
- Food digestion accounts for approximately 10 percent of calories burned. Known as diet-induced thermogenesis, thermic effect of food, or TEF, White says: “This is basically the energy it takes to digest and absorb and transport carbohydrates, proteins and fats.”
- Finally, a tiny component of your metabolism is adaptive thermogenesis: And this only applies if you’re exposed to cold climates. “That’s your body’s reaction to cold,” White says. “So, for example, if you lived in Barrow, Alaska, you would produce a little bit of heat to keep your body warm.”
What determines my metabolism's speed?
Many people wonder what they can do to increase their metabolic rate. There are several things that determine our metabolism that we cannot change, such as:
- Genetics: Physiological characteristics we inherit from our parents—genetics—account for 80 percent of our metabolism, Summers says. “There’s a huge genetic component to how [our bodies react to] the food we eat.”
- Gender: Men tend to have a higher metabolism than women. “Probably because of the anabolic effects of testosterone, which tends to build more muscle. And more muscle tends to increase the basal metabolic rate,” explains White.
- Age: Metabolism decreases with age. Part of this is the loss of muscle mass as you age. “Even accounting for the loss in protein, there is an age-related drop in basal metabolic rate,” White says.
- Height: The taller you are, the higher your metabolism, White says.
Metabolic rate is also highly individual and ever changing, depending on what you do throughout the day. Even between individuals with the same gender, weight, and body composition, metabolic rates can vary. Researchers don’t yet know why, White says.
What health conditions affectmy metabolism?
Certain diseases can affect your metabolism. Your endocrine system regulates hormones throughout your body that affect metabolism, mood, sexual function, and growth and development. Diabetes and thyroid disorders are two common endocrine diseases that impact your metabolism, according to the National Institute of Diabetes and Digestive and Kidney Diseases.
Your primary doctor, or a specialist known as an endocrinologist, can check your hormone levels to make sure you don’t have a condition that is affecting your metabolism. In some cases, such as with thyroid disorders, hormone replacement medication can get your levels back to normal.
RELATED: Why Am I So Tired?
How does my weight affect my metabolism?
It may seem counterintuitive, but the more you weigh, the higher your metabolism. That’s because the more you weigh, the more energy your body needs to keep it going, White says.
“It has real implications for when you do lose weight.
You can never go back to eating the same amount you did before,” says Lawrence Cheskin, MD, director of clinical research at the Global Obesity Prevention Center at Johns Hopkins Bloomberg School of Public Health.
“So that’s why people will often say, ‘This diet screwed up my metabolism.’ But it’s mostly proportional to the fact that now you’re a smaller person.”
Does what and how I eat affect my metabolic rate?
“What you eat doesn’t affect your metabolic rate very much,” Summers says. “I don’t know many dietary interventions that affect metabolic rate in a consistent way.”
Another thing to consider, your body has a set point and it wants to stay there, White says. That’s why crash dieting doesn’t work long term.
“If you eat too much, your metabolic rate slightly speeds up but not to the point that it offsets the number of calories coming in,” Summers says.
On the other extreme, severe calorie restriction might cause you to lose weight fast, but it slows down your metabolism and has other negative consequences.
Your body tries to become more efficient as a life-preserving measure to keep you from starving, Cheskin says.
“It adapts everything from your thyroid, to your degree of fatigue, to how much you sweat, and eventually, whether your hair starts to fall out because your body is trying to conserve energy.”
How does exercise affect my metabolism?
Activity is the largest component of metabolism that we can control, accounting for between 20 and 25 percent of our metabolism.
“Try and match your calorie intake with the amount of calories you’re burning safely,” Summers says. “If you don’t burn off the calories you take in, then you store them as fat. Any exercise, even the smallest amount of exercise has health benefits. So, something is better than nothing. And [more] is better than a little.”
What about exercise “afterburn”—doesn’t that help?!
Maybe you’ve heard of the metabolic benefits of exercise “afterburn”. The technical term for it is excess post-exercise oxygen consumption or EPOC.
It’s the extended increase in oxygen uptake after a b exercise, but it doesn’t have a significant contribution to energy expenditure, says Christopher Scott, PhD, professor in the department of exercise, health and sport sciences at the University of Southern Maine.
“While any increase in metabolic rate helps ‘burn calories,’ the contribution of EPOC is certainly helpful but ly minimal,” Scott says, adding that athletes may have more meaningful increases in metabolic rates due to their training demands, but regular physically active people “not so much.”
“The best way to take advantage of the afterburn (EPOC) period is to perform a low-intensity active recovery after a b exercise,” Scott says, who studies human performance and wrote a textbook on the topic, A Primer for the Exercise and Nutrition Sciences: Thermodynamics, Bioenergetics, Metabolism.
“As strange as it may sound, EPOC periods may be better associated with the utilization of fat as a fuel as opposed to a meaningful caloric cost. Fat is a favored fuel of working muscle at a lower intensity,” Scott says. “So brief periods of high intensity exercise or resistance training followed by a longer period of walking may serve as the ideal exercise prescription for weight loss.”
RELATED: How Exercise Burns Fat
How to Measure Resting Metabolic Rate
Knowing your resting metabolic rate—the calories you need to consume to maintain your body’s daily functioning—can help you to lose or maintain weight.
“Theoretically, since that’s 70 percent of your total metabolism, you can make adjustments to see what your total energy expenditure would be and then what would roughly be the number of calories you would need to consume to maintain your body weight,” White says. Here are three of the main ways it’s measured:
- Indirect calorimetry: How much energy you’re burning is directly proportional to how much carbon dioxide there is in your breath for your size. Indirect calorimetry uses a device to measure the amount of CO2 your body produces. Many doctor’s offices and health clubs have this equipment.
- Direct calorimetry: In direct calorimetry, you’re placed in an insulated water chamber to measure your body’s heat transfer. It’s a much more accurate measurement of energy expenditure, but it’s expensive and typically only found at weight loss clinics and medical centers.
- Harris-Benedict Equation: For the DIY approach, the Harris-Benedict Equation (HBE) uses age, gender, height, weight and activity level to estimate your resting metabolic rate. According to a 1984 study, HBE accurately predicted resting energy expenditure, another term for resting metabolic rate, in normally nourished individuals but not in those who were malnourished. There are several online Harris-Benedict calculators you can use.
RELATED: How to Increase Your Metabolism
What a dietitian wants you to know about boosting your metabolism
If you’ve ever been grabbed by headlines that claim to help you boost your metabolism, burn fat faster, or torch calories by taking a pill or eating some miracle food, I’ve got a spoiler alert: Your metabolism is pretty tightly regulated and there’s little you can do to speed things up.
This may come as a big surprise (and a big buzz kill!) but it doesn’t mean that you can’t lose weight, which is why most people are concerned with their metabolism in the first place. Here are some answers to your burning questions about metabolism.
Your metabolism is made up of a few components:
- Your basal metabolic rate, or BMR, basically refers to the calories you burn just to stay alive. Your body is really cool and does some pretty amazing things to keep you alive and functioning! It’s always hard at work — say, enabling you to breathe, pumping blood to your heart, and so much more — so you’re always burning calories. Your BMR accounts for 70-80 percent of the calories you burn and it’s highly variable from person to person. Age, gender, genetics, hormones and muscle mass play a role in your BMR.
- The thermic effect of food (TEF) is a complicated way of referring to the calories you burn digesting food. This process accounts for about 10 percent of the calories you burn.
- Non-exercise activity thermogenesis — or NEAT — is how we refer to the calories we burn through non-sports activities. This could include cleaning your kitchen, trying on clothes at the mall, and even just fidgeting. What’s truly neat about this is that this type of activity accounts for 10-20 percent of the calories you burn, and studies suggest that you can burn around 800 extra calories per day moving around a bit more, for example by doing things using a standing desk, taking the stairs instead of the elevator, and accumulating activity during routine chores, grocery shopping and cleaning the kitchen.
- Exercise activity thermogenesis is just a complicated way of saying physical activity, and it’s just what you’d expect — the calories you burn when you’re purposefully trying to break a sweat. Going for a power walk with a friend would count as physical activity but strolling around the grocery store — even while tracking and accumulating steps — would fall in the NEAT camp. If you’ve been keeping tabs on the math, you can see that physical activity can only account for about 5-10 percent of your metabolism, though taken together with NEAT, can add up to about 30 percent of your calorie burn.
The short answer is not by much. What this means is that while the impact may not be dramatic, it’s a factor that’s well within your control.
In addition to burning some calories, a big advantage of exercise is that it helps you increase your muscle mass.
The more muscle you have, the higher your BMR will be, since muscle is a very active tissue that demands a lot from your body. Since men have more muscle mass than women, they also have higher metabolisms than women.
Exercise only accounts for a fraction of calories burned whereas eating accounts for all of the calories you consume.
However, unless you’re a power lifter (and let’s face it, most of us aren’t), this metabolic boost is pretty small.
It’s not meaningless, but if all of your weight loss efforts are spent at the gym, you’re only putting in 5-10 percent of the work! Another way to put this: Exercise only accounts for a fraction of calories burned whereas eating accounts for all of the calories you consume. This (among other reasons) is why you should enjoy your movement experiences rather than torturing yourself in the name of burning calories.
You might expect it to, but more commonly, I’ve seen this lead to overeating, and therefore, weight gain. Remember that real life isn’t lab life, and even a review of studies that examined the effect of grazing found that the majority of time, it doesn’t help.
There are a few factors that can influence and optimize the TEF. You’ll get a slight boost if you’re eating sufficient protein (foods chicken, tuna, eggs, chickpeas and Greek yogurt), and this macro has another advantage. It keeps you fuller, longer, so it helps manage hunger.
Swapping processed and manufactured foods for whole ones is the other way to maximize the metabolic boost you get from eating.
Think of it this: Once food is processed, it’s much easier for your body to grab the energy (another way of saying ‘calories’) it needs.
That means you’re not going to burn as many calories from eating processed foods as you are from eating foods in their whole form.
Let’s get something clear: There are no shortcuts when it comes to losing weight.
It’s true that studies show that green tea and cayenne pepper may help, but the studies are short term or take place in test tubes or rodents, and they tend to use these substances in supplement form (rather than the food form, which is how most people consume them). And most importantly, the help is minuscule. It ly wouldn’t translate to any meaningful, long-term benefit.
There’s also evidence that apple cider vinegar may help with weight loss, but there’s evidence it can cause tooth erosion or esophageal damage so it’s not a strategy I’d advise.
Finding a sustainable place on the scale isn’t a race to drop pounds, and we don’t really know the long-term safety of these short-cut solutions.
Instead of spending your money on pills, enjoy these ingredients as part of a healthy eating pattern. Try a vinaigrette made with apple cider vinegar, or use it to dress a potato salad.
In the latter example, it makes some of the starch indigestible, which then allows that undigested starch to become the perfect fuel for your gut bacteria.
Drink unsweetened green tea (hot or iced) instead of popping supplements, and if you things spicy, by all means, add some cayenne pepper to your meals! But if you don’t care for spicy food, there are far better ways to lose weight than to spice your meals.
It doesn’t appear that it kills your metabolism in the way that you’re thinking about it. Think of it this: After gaining weight, your body feels at home at its new size.
When you begin to lose weight, your body begins to make adaptations because it recognizes there are changes happening at home.
These adaptations manifest as changes in the hormones that make you hungrier, and when you feel hungry, the typical response is to eat. This makes it hard (but not impossible) to keep the weight off.
The other irony is that as you lose weight, you actually need fewer calories to maintain your smaller frame. This is where metabolism comes into play.
Since your body is smaller, your metabolism adjusts to your new size, so on top of being hungrier, you require less food.
Also, if you aren’t eating carefully while trying to lose weight, you may lose some muscle, which will impact your metabolism.
There may be some exceptions, though. Some studies point to the fact that extreme dieting and weight loss — a la the “The Biggest Loser” contestants — might cause a dip in your metabolism below what would be suggested your new size.
One other thing to note here: While yo-yo dieting might not ruin your metabolism, it isn’t healthy. This habit is linked with an increased risk of heart disease.
Again, not for the reasons you might think. Smaller people actually have slower metabolisms since your BMR is related to your size. Recall that when you lose weight, your BMR adapts to compensate for a smaller body. However, we all know people who can seemingly eat anything they want and not gain weight.
(Yes, these people annoy me, too!) Though you might expect these people to have higher metabolisms, new research suggests that they may actually have genetic variations that are equivalent of hitting the metabolic lottery! Something is working in their favor, though we haven’t pinpointed exactly what that is yet.
One more thing on body size: it’s not an indicator of your health.
If you’re looking at two houses, does a blue house say anything about the foundation when compared to a red house? It’s the same thing with bodies.
Some healthy people have larger bodies and some healthy people have smaller bodies, and you can be naturally slim and have heart disease or diabetes, just as you can have a larger body and be healthy.
We’re learning more and more about the roles of sleep and your microbiome on the metabolic pathways that influence your weight. For starters, guard your sleep! Aim for the recommended 7 to 9 hours of sleep each night. If you have trouble hitting sleep targets, you can try establishing some healthy sleep habits.
A few to start with: Cut out caffeine after mid-day, create a relaxing bedtime ritual (reading and meditation are some ideas), and resist the urge to scroll through email or social media within an hour of bedtime.
Also, be careful with booze, since going above the recommended caps (one drink a day for women, two for men), interferes with restorative sleep.
The advice to drastically limit sugary and processed foods and focus instead on food in its whole form is a great step towards keeping your microbiome healthy.
Other things you can do: Embrace a variety of fiber-rich foods (think: veggies, fruits, beans, nuts, seeds and whole grains) since these foods get broken down into chow for the beneficial bacteria in your gut. Also, enjoy some naturally probiotic-rich foods, such as plain Greek yogurt or sauerkraut.
These types of foods plant more beneficial bacteria in your gut. Your microbiome has a huge impact on your overall health so this is good, all-around advice, regardless of your metabolism.
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