How does knowing your basal metabolic rate (BMR) help you lose weight? Discover the key factors that determine your BMR and how to use it to reach your weight loss goals.

Understanding BMR: The Cornerstone of Weight Management

Knowing your basal metabolic rate (BMR) is a crucial step in achieving your weight loss goals. BMR represents the minimum number of calories your body needs to function at rest, accounting for 60-75% of your daily energy expenditure. By understanding your BMR, you can set a realistic caloric intake and make informed decisions about your nutrition and exercise plan.

Calculating Your BMR: Factors to Consider

Several factors influence your BMR, including your age, gender, current weight, and activity level. BMR calculators, such as those offered by IIFYM, MyFitnessPal, and Bodybuilding.com, can help you determine your individual BMR based on these variables. Even if you don’t know your exact body fat percentage, these calculators can provide estimates based on visual cues.

Differentiating BMR and TDEE

While BMR represents your body’s basic caloric needs, total daily energy expenditure (TDEE) includes the calories burned through daily activities and exercise. To effectively manage your weight, it’s important to understand the relationship between BMR and TDEE, as TDEE is the number you’ll work with to adjust your macros and calories for your desired goals.

Leveraging BMR for Weight Loss

When it comes to weight loss, your BMR can be a valuable tool. By factoring in your BMR and TDEE, calorie-focused calculators can help you determine the optimal daily caloric intake for a calorie deficit, leading to gradual and sustainable weight loss. The key is to find a balance that avoids extreme calorie restrictions, which can be counterproductive in the long run.

Balancing BMR for Muscle Gain and Weight Maintenance

BMR and TDEE calculations are not limited to weight loss; they can also guide your approach to muscle gain and weight maintenance. For muscle building, you’ll need to strategically increase your caloric intake, likely focusing on protein and carbs, to support muscle growth. Conversely, if your goal is weight maintenance, knowing your BMR and TDEE can help you determine the ideal daily caloric intake to keep your weight stable.

Customizing Your Approach: The Importance of BMR

In the pursuit of weight management, whether it’s losing fat, gaining muscle, or maintaining your current weight, understanding your BMR is a crucial first step. By using BMR-based calculators and adjusting your nutrition and exercise accordingly, you can take a more personalized approach to achieve your desired body composition goals.

How Accurate are BMR Calculators?

While BMR calculators can provide a general estimate, they may not be 100% accurate for every individual. Factors such as genetics, body composition, and metabolic efficiency can influence your true BMR. If you’re seeking a more precise measurement, you may consider using a direct calorimetry test, which involves measuring the heat your body produces at rest.

Can BMR Change Over Time?

Yes, your BMR can fluctuate over time due to various factors, such as changes in age, body composition, hormones, and lifestyle. It’s important to periodically recalculate your BMR to ensure you’re working with the most up-to-date information and adjusting your nutrition and exercise plan accordingly.

How Does Exercise Impact BMR?

Regular exercise can increase your BMR, as your body requires more energy to maintain and repair muscle tissue. However, the extent of this increase can vary based on factors like the type, duration, and intensity of your workouts. Incorporating strength training, in particular, has been shown to have a more significant impact on boosting BMR compared to cardio-focused exercises.

Is BMR the Same as Resting Metabolic Rate (RMR)?

While often used interchangeably, BMR and RMR are not exactly the same. BMR represents the minimum number of calories your body needs to perform basic functions, while RMR is the number of calories your body burns while at complete rest. RMR is usually slightly higher than BMR, as it takes into account additional factors like body temperature and brain activity.

How Can BMR Help with Weight Maintenance?

Knowing your BMR can help you determine the ideal daily caloric intake to maintain your current weight. By balancing your caloric intake with your TDEE, which factors in your BMR, you can ensure that you’re consuming the right number of calories to sustain your weight without gaining or losing additional pounds.

Is BMR the Same for Everyone?

No, BMR can vary significantly from person to person due to factors like age, gender, body composition, and activity level. Individuals with more muscle mass tend to have a higher BMR, as muscle tissue requires more energy to maintain than fat tissue. Additionally, BMR generally decreases with age as muscle mass declines and metabolism slows down.

Knowing Your BMR Can Improve Your Chances of Losing Weight and More

If losing weight is your main goal, calculating your BMR is key.

Getty Images

If one of your goals is to lose body fat, gain muscle or even maintain your weight, you should know your basal metabolic rate, or BMR. Your BMR is the minimum number of calories that your body needs to function at rest. Overall your body needs a specific amount of energy to complete basic functions like breathing, your heart rate, digestion and regulating your hormone levels. The reason your BMR is a key factor is because it makes up about 60 to 75% of your daily energy expenditure. 

Your BMR is calculated based on several different factors that focus on your age, gender, current weight and activity level. Although BMR is not intended for 
weight loss
, the tool can show you information that can help you set a realistic caloric intake for yourself–whatever your goal may be.

Keep reading to learn more about BMR, how to calculate it and how it can be a guide for your nutrition and exercise goals.  

BMR calculators use several different factors, like age and gender, to determine your BMR.

Screenshot by Mercey Livingston/CNET

What is BMR and how do you find it?

Many people use BMR as a starting point to calculate their daily calorie needs and how to best adjust them to reach their goals. In fact, many macro calculators, like the popular IIFYM, incorporate BMR into their calculations for telling you about your calorie intake and macro needs based on your goals.

One common misconception about BMR is that it is the amount of calories your body burns at rest, but that is a different metric — resting metabolic rate, or RMR. Your BMR is what energy your body needs to perform basic functions, while RMR is the amount of calories that your body burns while at rest. Some people use the measurements interchangeably, but they aren’t necessarily the same thing. 

BMR calculators

There are many different calculators available online that can calculate your estimated BMR. Note that some of them will ask you to enter your body fat percentage, which many people do not know. If you don’t, you can make an estimate or use the images provided (like IIFYM does) to guess. 

Some of the best BMR calculators:

• IIFYM BMR calculator
• My Fitness Pal BMR calculator
• Bodybuilding.com BMR calculator

BMR and TDEE 

Once you start learning about your BMR, you will likely also find information on total daily energy expenditure, or TDEE, since BMR is often calculated first to find TDEE. 

Your BMR tells you your calorie needs, when you take that number plus how much you burn every day during normal activity and exercise, you get your TDEE. So really, TDEE is the number that you work off of for figuring out how to adjust macros or calories for body composition goals, according to IIFYM. 

Watch this: How Healthy is Your Heart, Really? 5 Ways to Tell at Home

03:59

How to use your BMR to help you lose weight

Weight loss is tricky, but using calculators that factor in your BMR are helpful for taking a more customized approach for your calories and macronutrient needs. The way that most macros and BMR-based calculators work is by factoring in your TDEE with your goals. 

If you want to lose weight, you have to be in a calorie deficit, meaning the calculator will set your daily food intake to equal less calories than what you burn. Sometimes when you take an online quiz to find this number, you will be asked how fast you’d like to lose weight. Then the calorie deficit will be adjusted accordingly. The faster you want results, the more extreme you will have to be with cutting calories. But many experts say that slow and steady is optimal compared to trying to lose a lot of weight quickly. 

If you want to maintain your weight instead of lose or gain, then knowing your BMR and TDEE can help you know how many calories you should aim to consume each day to maintain your weight. On the flipside of weight loss is gaining muscle mass. This too requires that you strategically approach your nutrition and add calories into your day (likely in the form of protein and carbs) to make sure you can gain muscle.  

More for your health and wellness

• Yes, You Can Build Muscle and Lose Fat at the Same Time
• 10,000 Steps a Day Won’t Keep You Fit. Here’s What Will
• This Is the Best Time of Day to Exercise, According to Science
• How Long Does It Really Take to Build Muscle?
• The Hormones Behind Happiness: How to Naturally Boost Dopamine and Serotonin

What Is BMR and TDEE + How to Use Them to Lose Weight

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Written by Nathan Phelps on March 29, 2019

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If you can’t measure it, you can’t manage it. 

It applies to most aspects of our life and especially weight loss.

Sometimes half the battle of losing weight is just knowing what to track and how to track it. 

For many people, weight loss success depends upon having an effective system of tracking calories.

Calories in, calories out (CICO), right?

Weight loss really is that simple, but how can you figure out how many calories you burn per day? In other words, how do you figure out your baseline and determine how many calories you should be eating?

That’s where understanding BMR (Basal Metabolic Rate) and TDEE (Total Daily Energy Expenditure) comes in. These formulas calculate how much energy you spend per day, and this allows you to set your calorie goals much more efficiently.

Once you understand your BMR and TDEE and the relationship between them, it becomes  a lot easier to reach your weight loss goals.

Let’s start with a bit more detail on what BMR and TDEE are, and then we’ll explore how you can incorporate both in your day-to-day weight loss routine.

WHAT IS BMR?

Basal Metabolic Rate is how many calories you burn when your body is resting.

In other words, it’s the calories your body needs to keep you alive. This is the bare minimum. Imagine you were in a coma — that’s the base level we’re talking about here.

Think of these as your “rainy day” or “couch-potato” calories. 🙂

No physical activity required!

People use BMR and other metrics to figure out how many calories they burn per day regardless of their physical activity. With BMR,  you can factor in your workouts and exercise to figure out how many calories you should eat per day to meet your weight loss goals.

Basal means “forming or belonging to a bottom layer or base”. It’s the fundamentals.

But, that doesn’t there isn’t a lot happening beneath the surface. In fact, between 60-75% of your daily calories are burned during these processes. 

Think about everything going on while you lie in bed: your heart has to pump blood, your lungs need to pull in and push out oxygen, and then that oxygen needs to be delivered to your brain and the rest of your body.

The energy required to perform fundamental processes like ventilation, blood circulation, and temperature regulation is dependent on your weight, height, age, and gender.

BMR is also used interchangeably with BEE (Basal Energy Expenditure) and is similar but not equal to RMR (resting metabolic rate) or REE (resting energy expenditure).

BMR is a slightly more restrictive definition than RMR, but many people confuse their definitions. True basal metabolic rate  calculation requires patients to spend the night in a test facility the night before official testing. If you’d like to be that exact, you’ll need an appointment.

Scheduling an appointment isn’t necessary, though!

For our purposes, we will be looking at the practical methods for calculating BMR, which essentially becomes RMR when calculated with a formula instead of testing.

So to clarify, getting an exact basal metabolic rate  is quite difficult, but using a formula to get an estimation is more than enough to get your weight loss goals underway.

Calculating Your BMR

People debate how best to calculate BMR, but the formulas all consist of some essential elements:

• Gender
• Age
• Weight
• Height
• Activity
• Body Fat (optional)

The quickest way to calculate your basal metabolic rate is to use an online calculator, which you can find here.

Or if you’d rather do the math yourself, you can use these gender-specific equations known as the Harris-Benedict Formula.

This Harris-Benedict Formula summary is via EverydayHealth.com.

MALE BMR FORMULA

BMR Formula:

66 + (6.23 x weight in pounds) + (12.7 x height in inches) – (6.8 x age in years)

Example:

So if you’re 170 pounds, 5’11”, and 43, your BMR is 66 + (6.23 x 170) + (12.7 x 71) – (6.8 x 43) = 1,734.4 calories.

FEMALE BMR FORMULA

BMR Formula:

655 + (4.35 x weight in pounds) + (4.7 x height in inches) – (4.7 x age in years)

Example:

So if you’re 130 pounds, 5’3″, and 36, your BMR is 665 + (4.35 x 130) + (4.7 x 63) – (4.7 x 36) = 1,357.4 calories.

—

Got it? Alright! Once you’ve used a BMR calculator, TDEE is what you should look at next!

WHAT IS TDEE?

Total Daily Energy Expenditure (TDEE) is an estimation of how many calories you burn each day, including physical activity. It is calculated by multiplying your Basal Metabolic Rate by 1.2 – 1.9 based on your activity level.

TDEE is just BMR with estimations added in. It’s the same formula except you add in a multiplier that’s dependent on how much “activity” you have in a given day.

So for example, if you exercise 3-5 days per week, you’d multiply your BMR by 1.55.

You think of TDEE as adding in everything you do in a normal day to your basal metabolic rate  calculation. And once you start using a TDEE calculator, weight loss will likely follow.

This includes all of our physical exercise as well as all of the little things we do throughout the day like showering, walking around the office, taking out the trash, cuddling with puppies, yelling at the TV… You know. Normal stuff.

Your TDEE is simply a measure of the number of calories needed to accomplish your basic, daily activities + your BMR.

If your calorie consumption is equal to your TDEE, you will maintain your current weight.

If your calorie consumption is less than your TDEE, you will lose weight and uncover more lean body mass.

It’s really that simple.

Calculating Your TDEE

Based on the amount you exercise, use the following multiples:

• If you rarely exercise, multiply your BMR by 1.2
• If you exercise on 1 to 3 days per week, multiply your BMR by 1.375
• If you exercise on 3 to 5 days per week, multiply your BMR by 1.55
• If you exercise 6 to 7 days per week, multiply your BMR by 1.725
• If you exercise every day and have a physical job or if you often exercise twice a day, multiply your BMR by 1.9

Just like basal metabolic rate, you can quickly calculate your total daily energy expenditure  using the TDEE formula online calculator here.

So following the EverydayHealth examples, if the man exercises 3 days a week, his daily caloric requirement is 1,734.4 x 1.55, or 2,688.3 calories.

And if the woman in the example exercises 6 days a week, her daily caloric requirement is 1,357. 4 x 1.725 or 2,342.5 calories.

USING BMR AND TDEE TO LOSE WEIGHT

Once you know your BMR and TDEE, all you need to do is make sure your caloric intake is less than that number!

So if your TDEE ends up being 2,200 calories per day, you need to eat fewer calories to achieve “weight loss”.

How fast you lose it depends on how much your deficit is every day.

Generally speaking, there are about 3,500 calories in a pound.

In seeking weight loss, most dieticians recommend eating a deficit of anywhere between 500-1,000 calories a day.

The goal is not to lose weight the fastest — it’s to be consistent.

When you need motivation over long periods of time (like a weight loss journey), the tortoise approach generally trumps the hare mindset.

So looking at a TDEE of 2,200, if you aimed for 1,700 calories per day, you’d be eating at a 500 calorie deficit. At this rate, you’d lose approximately 1 pound per week.

To  test the accuracy of your TDEE, follow this deficit and see if your weight drops by about a pound per week. If not, you may be over or underestimating your BMR or TDEE multiplier.

Pretty cool, right?

Weight Loss in Practice

Then, all you need to do is track your calorie intake and the calories your body burns via an app like MyFitnessPal and adjust your TDEE multiplier as your exercise routine changes.

I’d also grab a cheap kitchen scale if you don’t have one already — being able to measure out your foods saves a lot of guessing and headaches when calorie counting. You can grab one for $10 or so on Amazon, and they also help a lot when meal prepping.

Meal prepping is going to be your best bet for staying on top of a calorie deficit! You can make one big meal, split it by calories and weight into separate containers, and just grab and go.

The more barriers you can break down when having to think about your calories, the better you will do.

Here are some great meal prep recipes for you to dig into.

CONCLUSION

There you have it!

Again, the relationship between BMR and weight loss and TDEE is key to accurately setting your weight loss goals.

Just knowing what your body needs and how your unique BMR and TDEE affect your weight loss strategy will help you immensely when trying to lose weight.

Without your metrics, you’re just guessing.

Start by calculating your BMR — reduce as many variables as you can, and then figure out your TDEE.

Once you have your numbers, use a calorie calculator, pick an energy deficit  that you feel confident sticking to, and start your journey toward the life of your dreams.

Wishing you all the luck!

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✍️ ABOUT THE AUTHOR 📚

Nathan Phelps

Nathan Phelps is a foodie, writer, marketer, and musician living in the great city of Nashville, TN. He loves the intersection of healthy eating & science, and his daily activities include co-opting coffee shops as offices, morning optimism, afternoon doubt, and a nice swig of evening regret before bed.

How to calculate your daily calorie intake to lose weight and not hurt yourself

March 28, 2016

Health

Eating right and reducing calories is the safest and most reliable way to lose weight. But how many kilocalories to take as a guideline? It all depends on your gender, age, weight, height and physical activity. In this article, we’ll show you how to calculate your personal daily calorie intake. You will need basic knowledge of algebra and 10 minutes of your time.

Calculate the need for calories

At the first stage, we calculate the basal metabolic rate (BMR) — the number of calories that the body needs to receive during the day for normal functioning at rest. That is, this is the amount of energy spent per day on breathing, digestion of food, restoration and growth of tissues, as well as blood circulation. This value can be determined in two ways: using the Harris-Benedict equation and based on the Mifflin-Jeor equation.

Take for example a couple of young people with a body mass index of 27.78 (young man 30 years old, height 1.8 m and weight 90 kg) and 25.71 (25-year-old girl 1.65 m tall and weighing 70 kg) . According to WHO definitions, they are overweight and even obese. Surely this is not very noticeable in clothes, but the “ears” on the sides will not let you lie.

Harris-Benedict formula

Francis Gano Benedict was an American chemist, physiologist and nutritionist, one of the pioneers in the study of metabolic rate and oxygen consumption. At 19In 1919, he published the scientific work A Biometric Study of Basal Metabolism in Man, which later became an absolute classic in his field. The work was co-authored by Francis’ compatriot, botanist James Arthur Harris. The scientists stated that the approximate value of BMR can be determined based on the surface area of ​​the body, and proposed a corresponding formula.

In 1984, changes were made to the original calculations. By the way, many online daily calorie calculators have not heard about these adjustments. We will provide an updated version. Just get familiar with it and take your time counting.

Calculation for men: 88.362 + (13.397 × weight [kg]) + (4.799 × height [cm]) − (5.677 × age [years]).

88.362 + (13.397 × 90) + (4.799 × 180) − (5.677 × 30) = 88.362 + 1205.73 + 863.82 − 170.31 = 1988 kcal/day

Calculation for women: 447.593 + (9.247 × weight [kg]) + (3.098 × height [cm]) − (4.33 × age [years]).

447.593 + (9.247 × 70) + (3.098 × 165) − (4.33 × 25) = 447.593 + 647.29 + 511.17 − 108.25 = 1498 kcal/day

Confidence interval with confidence level 95% is ± 213.0 kcal/day for men and ± 201.0 kcal/day for women.

Mifflin-Jeora Formula

This formula was created in 1990 in response to lifestyle changes over the past 100 years.

Calculation for men: 5 + (10 × weight [kg]) + (6. 25 × height [cm]) − (5 × age [years]).

5 + (10 × 90) + (6.25 × 180) − (5 × 30) = 5 + 900 + 1,125 − 150 = 1,880 kcal/day

Calculation for women: (10 × weight [kg]) + (6.25 × height [cm]) − (5 × age [years]) − 161.

(10 × 70) + (6.25 × 165 ) − (5 × 25) − 161 = 700 + 1,031.25 − 125 − 161 = 1,445 kcal/day.

Subtotals

As you can see, different approaches give slightly different results. Which formula do you prefer? For an answer, I turned to professionals – employees of BODYCAMP.

Natalia Nefyodova

Dietitian, nutritionist, psychologist, author of scientific papers.

There are many more formulas (for example, The Institute of Medicine Equations, Danowsky Equation, and others) for determining the daily calorie limit, and each of them is good for a nutritionist in its own way.

For example, I use separate formulas, when evaluating a patient in a hospital. Any serious illness is stress that increases metabolism and, as a result, calorie consumption. Not to mention the case if the patient has a fever. There are formulas that should not be used for obese or overweight patients. The Harris-Benedict formula is one of them. She overestimates the daily calorie limit by 5-15% (and underestimates for men over 65).

At the moment, researchers are inclined to believe that the Mifflin-Jeor and WHO formulas give the closest result to the truth. These formulas can only be used by healthy people with normal body weight. However, I advise you not to consider the value obtained as a panacea. There are many factors that can affect metabolism, shifting it in one direction or another, for example, medications, muscle mass, spicy foods, smoking, and so on. Daily calorie limit calculation is just one of the tools that will help you stay fit and healthy.

By the way, Natalia graduated from McGill University (Canada) and has been working in her specialty for nine years. Let’s take her advice and focus on the Mifflin-St. Jeor equation. Let’s move on to the second step.

Making allowance for physical activity

As much as we would like an eternal Sabbath, it only happens once a week. And the rest of the time we work, take care of the house and, in general, overcome laziness. This takes forces that must be taken into account in the total amount of energy consumption. For this, correction factors are applied:

• 1.2 – if your activity mainly comes down to moving from bed to sofa;
• 1.375 – if you are more active and drown your conscience with light workouts 1 to 3 times a week;
• 1.55 – if moderate exercise is not alien to you 3 to 5 times a week;
• 1.725 – if you load yourself with hard training 6-7 times a week;
• 1.9 – if you give all your best (work physically, train twice a day, do strength exercises).

Let’s assume that our fictional characters are typical office workers. Their sedentary lifestyle corresponds to the first point. We will use it in our calculations.

1880 × 1.2 = 2256 kcal/day and 1445 × 1.2 = 1734 kcal/day

But how to properly manage these numbers? Now let’s explain.

Reduce calorie intake

We are all adults and we are aware that too much weight loss will worsen our health, especially if it is not Siberian at all. You need to lose weight gradually so as not to expose your body to stress. So how much to cut the ration? Let’s turn to the experts for advice.

The simplest rule used by nutritionists (at least in North America) is minus 500 calories per day, or 3,500 per week. Such a deficit will lead to a loss of 500 g of fat mass per week. However, the weight is recommended to reduce for six months. Then the daily calorie limit is recalculated and the weight is maintained for another six months. If necessary, the algorithm is repeated. Thus, 250-500 g (depending on the initial body weight) is the maximum safe weight loss per week. Exceeding this figure means loss of muscle mass and water. Again, this is not a panacea. Metabolism is changing and will constantly and rapidly increase if a person, in addition to modifications in the diet, exercises regularly. Therefore, this figure will also need to be changed. I advise you to use this rule on your own for those for whom the desired weight loss is no more than 5 kg of fat mass. For the rest, unfortunately or fortunately, it is better to consult a specialist. I would also like to add that you should not consume less than 1,200 kcal per day. This will necessarily lead to a shortage of both micro and macro elements.

Natalya Nefedova

We get that our fictional couple should reduce the daily calorie intake to the following indicators:

2 256 − 500 = 1 756 kcal / day 34 kcal/day

Please note that the numbers obtained are less than the base metabolic rate, and the girl generally approached 1,200 kcal per day. This can be dangerous: the body will burn muscle mass. Therefore, our heroes should increase their daily calorie intake to the level of BMR, let the weight loss go a little slower.

If our young people were more active, their daily calorie requirement would look like this:

1880 × 1.375 = 2585 kcal/day

Subtract 500 kcal and get values ​​in excess of BMR:

2585 – 500 = 2085 > 1880 kcal/day and 1987 – 500 = 1487 > 144 5 kcal/day

How to track your nutrition

Studies show that people who keep a food diary follow their diet more strictly and lose fat faster than those who do not. Clearly presenting the calorie content of food sent to the stomach, it is easier to pull yourself together and close your mouth in time.

Record each meal in a diary and calculate the total calories. At the same time, you do not have to memorize the energy value of all products. It is enough to know about the calorie content of popular dishes, imagine 200 calories in pictures, or capture in memory the highlights from the video “What 2,000 calories look like”. Although, of course, it’s easier to keep some electronic calorie calculator handy, for example, Dialife for iOS.

Conclusion

In conclusion, I will quote the opinion of Ekaterina Jensen, the author of many Lifehacker publications on the topic of healthy eating, who noted: “All formulas have errors. Simply because they generalize all people. And the level of personal metabolism is individual. It depends on both physical form and heredity. Not to mention the fact that, for example, spicy food increases metabolism. The formula is a formula, but all this is purely individual.

Therefore, you should not take the calculation of the daily calorie intake for a “diet pill” – it may simply not work due to your physiological characteristics and health status. It’s worth a try, but if you feel worse or if there are no results, you should seek help from a nutritionist.

Losing weight without a calorie deficit – is it possible?

I believe that the calorie theory of obesity is perhaps one of the most serious errors in the history of medicine. It is based on a completely wrong interpretation of the energy balance equation.

Body Fat = Calories Gained – Calories Burned

This equation, known as the energy balance equation, is always TRUE. Therefore, looking at it, people say things like “It’s all about the calorie deficit that you eat” or “The essence of all diets is calorie restriction.” In order to expend calories, we often hear: “you have to exercise more.” This is the standard approach – eat less, move more. Doctors, overweight experts, say things like this all the time, but they are wrong, not understanding what exactly. Is it possible to lose weight without a calorie deficit? The answer is yes.

Eating fewer calories burns fewer calories

The energy balance equation (which, again, is always true) is NOT the “eat less, move more” approach. What’s the matter?

Body Fat (No Change) = 2000 Calories In – 2000 Calories Expended

Burning calories is more than just exercising. It consists of 2 parts – energy expenditure at rest or basal metabolic rate (BMR), and physical activity of a person. If physical activity is taken as 0, the average BMR is 2,000 calories per day. This energy is used by the heart, lungs, kidneys, goes to maintain normal body temperature, etc. It should be noted that BMR is NOT under conscious control. You cannot control how much blood your heart pumps. You can’t “force” a body to generate more heat. No amount of willpower will make your kidneys use more energy.

Exercise is a small part of your daily energy expenditure unless you exercise several hours a day. Consider an exercise of medium difficulty – 1 hour of moderate walking / running, 3 times a week. During each walk, you burn approximately 100-200 calories. If you have ever run on a treadmill with a calorie counter installed, you know how slowly the numbers on the counter increase. Those 100 calories that you expended during physical activity pale in comparison to the 2000 calories eaten on average per day. So, we can safely ignore the effect of exercise if your workout lasts less than 1 hour a day.

People believe that if they reduce their calories by 500 per day or 3500 per week, they will burn about 450 grams of fat per week. It is believed that 450 g of fat is equivalent to approximately 3500 calories.

-500 calories = 1500 calories consumed – 2000 calories burned

Note that in order to burn fat, calorie loss MUST be stable. This is a prerequisite. But it is here, and it has been known for more than 100 years, that the MISTAKE lies. The basal metabolic rate (BMR) can increase or decrease by 30-40%. This has been proven back in 1917, when studies showed that a 30% reduction in calorie intake was accompanied by a rapid 30% decrease in BMR.

Dr. Ansel Keyes showed a similar effect in his famous “hunger study” in Minnesota. Despite the name, the subjects consumed 1,570 calories per day, more than popular diets suggest. A 40% reduction in calorie intake was accompanied by a 40% drop in BMR.

The reason is very simple – the body’s defense mechanism is triggered. If you do not change the level of hormones (mainly insulin), the body will not be able to access its fat stores. If you cannot get energy from stored fat, then you cannot enter a stable energy deficit. If you consume only 1500 calories per day, you can only burn 1500 calories.

So BMR can change. If you reduce the number of calories consumed daily, your body will burn less of them, and the body will not use fat reserves. The weight loss will plateau and then you will start gaining weight again. So, counting calories as a weight loss strategy is untenable, which has been proven many times.

Diets that lower the amount of insulin produced (low carbohydrate diet, intermittent fasting) are fundamentally different. By reducing the production of insulin, we tell our body that there is no food. So he switches from burning calories from food to calories from body fat stores. Instead of limiting energy expenditure, the body switches to another source. But this can only happen if we correct the underlying hormonal problem of excess insulin. So the “calories in and out” approach is completely useless? Well, not quite.

Is counting calories for weight loss completely useless?

You may have heard or received email notifications known as Nigerian Letters. The story is next. A few years ago, scammers sent millions of emails to potential victims. They say that the recipient is written by an exiled Nigerian prince who was forced to flee his native country. He has $10 billion in the bank and offers to split it with you if you only give him your banking information. In other letters, the scammers asked for money. Send them $1,000 so they can go to the bank, get their $10 billion, and give you $2 billion as a thank you. The scam became well known and most people immediately understood what was happening, so they simply deleted such letters.

However, contrary to expectations, the scam did not disappear. I still receive these letters regularly, they come from the name of a Nigerian prince, and not from, say, an Indonesian princess. What is the point of this scam?

Fraudsters with the help of such letters immediately determined the contingent of their victims. If they decided to start a new scam, they would get a lot of email responses, but most of them wouldn’t be gullible enough to transfer real money. By keeping the Nigerian prince scam alive, they could immediately and effectively identify the most gullible people who would pass the cash. Thus, the Nigerian prince scam is a great way to expose gullible people.

The Calorie Intake and Expenditure (CICO) model does the same for me. The CICO model has been tested over and over again. Many tests have shown that it is ineffective.

If someone advocates the CICO theory, I classify such people as those who do not really understand what causes obesity, and do not understand the mechanisms of weight gain. I often ask people who insist that weight loss is all about calories: “Do all calories cause weight gain?” to which they usually stare at me in disbelief before answering “it’s all about calories”, as if the body has some real method of measuring calories.