Basal metabolism: formulas and methods for calculating basal metabolism. Basic (basic) metabolism

The concept of basic metabolism is of interest to anyone who is at least more or less interested in the topic of losing weight and healthy eating... and me, of course, including. To my surprise, there was no information on this topic in RuNet that could be trusted from sources. For this reason, I had to look in the burzhunet. I found it on English-language Wikipedia, translated it, and share it.

The basal metabolic rate (BMR) and the directly related concept - resting metabolism (RMR) determines how much energy will be expended by a person (or animal) at rest on a daily basis.

That is, the numerical value of the BER clearly shows how much energy your body will need to maintain its own life support when your body is at rest and does not expend additional energy, for example, on physical activity. Typically, the numerical expression of the basic metabolism of an adult is in the range from 1000 to 3000 kcal/day, and depends on the physiological characteristics of the individual.

The state of rest should be understood not only as not performing any physical actions, but also as being in neutral temperature conditions. In addition, at rest, in the gastrointestinal tract, the absorption process (the process of assimilation of food) should not occur, since it is energy-consuming in itself and requires glucose for its implementation.

What is actually measured is the amount of energy released and used to ensure the functioning of vital organs: heart, lungs, nervous system, kidneys, liver, intestines, genitals, skin and muscles (particularly those necessary for breathing).

DEFINITION

The human body produces heat, a property known as thermogenesis. The amount of heat generated can be measured and thus the energy consumption can be determined. Basal metabolic rate (BMR) tends to decrease with age and reduction in muscle mass (which can also occur over the years). An increase in muscle mass increases the rate of BWB, but this effect is not so significant as to consider it as a method suitable for reducing body weight. Previously, it was believed that fitness aerobics could influence basic metabolism. This opinion turned out to be erroneous and the data on BOV provided in the 90s do not correlate with the data on BOV adjusted for fat-free body weight. New research indicates that anaerobic training (not to be confused with aerobic training) can increase resting energy expenditure. In addition, illness, previously consumed food and drinks, ambient temperature and stress can affect overall energy expenditure and BEF in particular.

Basal metabolic rate is measured under strictly controlled conditions. Accurate measurements of BOV require that the person is awake and that nothing has an effect on his sympathetic nervous system, in a state of complete rest. A more common and less rigorous method is resting metabolic rate measurement (RMR).

Both of these indicators are measured using gas analysis using direct or indirect calorimetry. There is a simpler (rougher) way - through a formula that takes into account the age, gender, height and weight of the person being studied.

PRACTICAL APPLICATION OF CALCULATED VALUES OF BER

Basal metabolic rate (BMR) is usually the most significant component of energy expenditure. That is, the human body spends the bulk of the energy received on basic metabolism. However, the Harris-Benedict formula is approximate, and differences in BOV (taking into account differences in the ratio of muscle mass to fat in different people), the degree of physical activity and the difference in the amount of energy expended on thermogenesis make it very difficult to assess the dietary component of any special individual needs, in order to maintaining body weight.

Calculating basal metabolism using a formula does not provide a sufficiently objective result. The result obtained is only suitable for statistical information and is not suitable for adjusting the diet of a particular person in order to maintain, reduce or increase his body weight.

PHYSIOLOGY

Basal and resting metabolic rates are usually expressed in terms of daily energy expenditure. In early work, scientists J. Arthur Harris and Francis G. Benedict provided approximate values ​​that were calculated based on: body surface area (calculated using weight and height values), age and sex, along with gas analysis values ​​measured using calorimetry. Studies have also shown that if you eliminate the gender factor (which occurs due to the fact that men and women accumulate fat differently) and calculate the BVR for a “fat-free” body (muscle mass), the values ​​of basal metabolic rate remain almost identical, regardless of gender accessories. In the literature on practical physiology there are tables with which you can calculate the body surface area based on data on height and weight and, accordingly, find out your approximate BOV.

The main organ responsible for metabolism is the hypothalamus, here are its functions that in one way or another affect metabolism:

Controls and integrates (links) the autonomic nervous system (ANS). The ANS controls the contraction of smooth muscle and cardiac muscle, along with the control of the secretion of many endocrine organs, in particular the thyroid gland (malfunction of which leads to metabolic disorders). Also, through the ANS, the hypothalamus regulates the heart rate, the speed of food movement in the gastrointestinal tract and contractions of the bladder.

Causes and regulates feelings of anger and aggression.

Regulates body temperature.

Responsible for food consumption through 2 centers: the nutritional center (hunger center) and the satiety center. The nutritional center regulates the feeling of hunger and thereby makes us look for food. When the body has received a sufficient amount of food and the level of leptin (a hormone that regulates energy metabolism) is high enough, the satiety center sends impulses that suppress the impulses of the hunger center. Accordingly, when there is not enough food, the hypothalamus activates the hunger center.

Regulates the feeling of thirst. The thirst center works in the same way: certain cells in the hypothalamus are sensitive to the osmotic pressure of the extracellular fluid. If thirst is satisfied, osmotic pressure decreases and the person no longer experiences thirst.

All of the above processes are parts of a complex “mechanism” that ensures the survival of the organism, which, in turn, supports all processes occurring in the body, and BOV and SME are a numerical reflection of their activity.

FORMULAS FOR CALCULATING BASIC METABOLISM

At the moment, there are several formulas. Historically, the most frequently mentioned method for calculating BOV is the Harris-Benedict formula, which was created in 1919.

ORIGINAL HARRIS-BENEDICT FORMULA:

For men:

For women:

Where P- the total amount of heat produced in a state of complete rest, m- weight, h- height, a– age, and the difference between the BOV of men and women is mainly in the estimated difference in weight. For example: a 55-year-old woman, weighing 59 kg and height 168 cm, will have a BOV equal to 1272 kcal/day, which corresponds to 53 kcal/hour, and is also equal to 61.3 watt/hour.

In 1984, the original Harris-Benedict formula was revised and refined, taking into account new data. Thus, the results obtained became more accurate.

IMPROVED HARRIS-BENEDICT FORMULA:

For men:

For women:

Up until 1990, this equation was considered the best. In 1990, Mifflin introduced this formula:

MIFFLIN SAN JEORA FORMULA:

Where s equals +5 for men and -161 for women.

Recalculating the above example, it turns out that a 55-year-old woman, weighing 59 kg and height 168 cm, will need 1204 kcal, instead of 1272. This difference in calculation is a consequence of lifestyle changes over the past 100 years and at the moment it is believed that such an adjustment is within 5% gives a more truthful result.

These formulas are based on total body weight, without taking into account differences in metabolic activity depending on the fat component of body weight.

Due to this imperfection of the presented formulas, it turns out that if we take, for example, 2 men with identical data on age, weight and height, then the calculated results for them will be absolutely the same. In reality, their BOV can differ significantly, due to the fact that one will be “pumped up” and the other “fat”.

There are formulas that take into account the fat component of body weight. One of them is Ketch-McArdle, the other is Cunningham. It should be noted that the Cunningham formula exists for predicting resting metabolic rate (RMR/MRP).

KATCH-MCARDLE FORMULA:

Where L.B.M., body weight minus fat.

According to this formula, if the woman from the above example has 30% fat in her body (there are different methods for calculating the amount of fat: using calipers, ultrasound, using biometrics, etc.), then, accordingly, her BOV is equal to 1263 kcal.

CUNNINGHAM FORMULA:

The essence of calculating BOV without taking into account fat mass is that fat cells require much less energy to remain stable than muscle mass. Therefore, such calculations are considered more accurate. Especially for athletes who, as a rule, have muscle mass significantly greater than fat mass.

To calculate your daily calorie needs, take your basal metabolic rate and multiply it by your physical activity ratio (PFA). CFA has values ​​from 1.2 (for people with no physical activity) to 2.4 (for athletes participating in highly physically intense sports).

REASONS FOR DIFFERENCES IN INDIVIDUAL BV INDICATORS

Each person has his own individual basal metabolic rate. One of the studies conducted in Scotland, which involved 150 people, showed the following results: the minimum BOR indicator is 1027 kcal per day (4301 kJ/day), the maximum is 2499 kcal per day (10455 kJ/day). In total, the average was 1500 kcal/day (6279 kJ/day). Statistical calculations showed that in 62.3% these indicators were associated with differences in the amount of muscle mass among the subjects. Other factors: volume of internal fat (not subcutaneous) (6.7%), age (1.7%), experimental error (2%). The remaining differences in BOV (26.7%) remained unexplained. These differences are not explained either by gender, or by the presence of fat and muscle mass in any proportion, or by volume dependence in energy-consuming organs such as the brain.

Thus, differences in BOV indicators are present even if two seemingly identical, according to the required data, individuals are compared: the same weight, the same muscle mass. The highest metabolic rate (28-32% more than the average) was observed in 5% of people; people with a slow metabolism of only 5% were classified as slow metabolism.

For example, in one study, almost extreme results were obtained when two people with identical muscle mass of 43 kg had a difference in basal metabolism of 715 kcal/day. In the initial figures, this was 1075 kcal/day and 1790 kcal/day, which in terms of energy consumption is comparable to a 10-kilometer run.

BIOCHEMICAL PROCESSES

About 70% of energy is spent by a person on basal (basic) vital processes occurring inside various organs of the body. About 20% of energy is spent on physical activity and another 10% on thermogenesis or digestion of food (postprandial thermogenesis). All these energy-intensive processes require oxygen in combination with coenzymes (derived from macronutrients: carbohydrates, fats, proteins), the residual result of these processes is carbon dioxide, according to the Krebs cycle.

Most of the energy used within the BOV itself is spent on maintaining fluid levels in tissues through osmoregulation, and only a tenth of the energy is spent on mechanical work: digestion, pulse and respiration.

The Krebs cycle allows you to convert fats, proteins and carbohydrates into energy, the presence of which can be designated as the ability or potential to do work. The breakdown of large molecules into smaller ones is associated with the release (production) of energy and is called catabolism. The process of creating molecules - anabolism, on the contrary, requires energy expenditure. The breakdown of proteins into amino acids is an example of catabolism, and the creation of protein from amino acids is an anabolic process. The combination of these processes is metabolism as such.

AEROBIC AND ANAEROBIC EXERCISES

Studies conducted in 1992 and 1997 showed that aerobic exercise does not correlate (do not agree) with basal metabolic rate. As a result of both studies, it turned out that aerobic exercise does not in any way increase the potential energy consumption (power) of muscle mass and, as a result, does not affect BF.

In turn, anaerobic exercises, such as weightlifting, promote the growth of muscle mass and, as a result, have an effect on BOM. However, the tangible effect of such exercises and the impact on metabolism is still an open question. Various studies show that the metabolic rate increases by 55 kcal for every kilogram of trained muscle. Thus, even a significant increase in muscle mass only slightly affects the BMR.

Also, some studies have found that 20-25 minutes of cardio training (a type of aerobics) can briefly increase (accelerate) BMR by about 10%, due to the fact that muscles increase their energy consumption to replenish glycogen reserves.

LIFESPAN AND METABOLISM

In 1926, Raymond Pearl proposed that life expectancy is inversely proportional to basal metabolism (the “rate of life” hypothesis). The basis for this hypothesis comes from the fact that mammals with larger body sizes have a longer maximum lifespan, and that the lifespan of the fruit fly is inversely proportional to ambient temperature. In addition, the lifespan of flies can be increased by limiting their physical activity. This theory has been supported by several new studies revealing a relationship between the lower threshold of basal metabolism and life expectancy, relevant for the entire animal kingdom and humans, including.

MEDICAL CONSIDERATIONS

Human metabolism varies depending on physical condition and activity. Strength (anaerobic) training has a greater impact on BOM than aerobic training, but there are still no mathematical formulas and dependencies that allow one to calculate the effectiveness of the loads and the degree of their influence on basal metabolism.

Reducing your food intake can lower your metabolic rate because the body will try to conserve energy. Researcher Gary Foster believes that very low-calorie diets (less than 800 kcal) can reduce metabolic rate by more than 10%.

Metabolic rate can be affected by medications: some antidepressants can slow down metabolism and cause excess weight. The same applies to medications for the treatment of hyperthyroidism.

Some research has focused on developing drugs to treat obesity by increasing metabolic rate, such as drugs that accelerate the rate of thermogenesis in skeletal muscle.

Studies of the physical condition of long-lived people, with an age of more than 100 years, have shown a direct connection with “decreased activity of the thyroid gland,” as a result of which these people have a somewhat slower metabolism. Which is considered an attribute of their longevity.

Metabolic rate may be increased due to stress, diabetes, illness or menopause.

The two formulas in the calculator below calculate the amount of calories your body needs based on gender, age, body weight, waist circumference, and level of daily physical activity (or exercise).

Female Male Your gender Your age in years Your height in cm. Your weight in kg. Waist circumference in cm. minimum physical activity 1-3 times a week physical activity 3-5 times a week physical activity 6-7 times a week heavy physical labor + training 2 times a dayPhysical activity
Formula

Before we begin the calculation, let's define medical terms.

What exactly is metabolism? Metabolism, or metabolism, is a complete process of chemical reactions in the body that ensures its vital functions, growth, and physical activity.

Basal Metabolism- this is the main metabolism that ensures breathing, blood circulation, and digestion of human food in a state of minimal physical activity. This is the amount of heat calculated for 1 kg of human body per day. To carry out the calculation, an experimental patient can be placed in a breathing chamber or a certain respiratory coefficient can be derived for him through measurements.

It is clear that since the metabolism is basal (basic, lower), it is better to conduct the examination at a moment of complete relaxation, in the morning on an empty stomach, and also taking into account those factors that affect the acceleration or deceleration of metabolism. These factors are from the field of endocrinology, and thyroid dysfunction can serve as an example. Such diseases affect your body weight regardless of how much you eat. You can starve and still be fat, and then there is definitely a direct path to an endocrinologist.

The effect of food consumed on metabolism should be considered from the main point of view - acceleration or slowdown of metabolism.

For example, all food, being a source of energy for the body, thus carries a thermal effect. However, some foods have a much greater and longer-lasting effect: these are carbohydrates rich in fiber, as well as protein foods such as meat and fish. The body spends about 30% of calories digesting them - which means that the metabolism works to burn your extra pounds.

There is also such an indicator as glycemic index. It is high in those foods from which sugar is absorbed instantly and goes into the blood. These are the so-called simple carbohydrates. But if you consume carbohydrates with a low glycemic index, that is, long-digesting ones (vegetables, cereals), then your metabolism again works for you, being in good tone.

Calculation formulas:

Muffin-Jeor Formula, launched in 1990, believes this:
P = 9.99 * weight (kg) + 6.25 * height (cm) - 4.92 * age (years) + constant (different for men and women).

Ketch-McArdle formula takes into account the ratio of muscle mass to body fat:
P = 370 + 21.6 * LBM (kg), where LBM is body weight minus fat.

If you are interested in doing your own calculations, which in your opinion are more accurate, calculate the specific gravity of fat deposits in your body, using also other health calculators available on the site.

Forum link Calculate basal metabolic rate and calorie needs Link for website or blog Basal Metabolic Rate and Daily Calorie Needs

The basal metabolic rate (BMR) is the minimum number of calories required to maintain the body's vital functions in a state of complete rest. Simply put, this is the amount of energy (measured in calories) that your body will expend if you sleep all day. Basal metabolism can burn up to 70% of the total number of calories expended, but this figure varies depending on various factors (we will talk about them below). Calories are spent on various physiological processes, such as breathing, blood circulation and maintaining the desired body temperature. Naturally, the average body expends more calories than BOO.

Basic metabolism is one of the most important factors determining the intensity of metabolism in general. This indicator tells us how many calories the body needs to maintain, lose, or gain weight. The amount of basal metabolism is determined by a combination of genetic (internal) and external factors, such as:

Genetics. Some people are born with a faster metabolism, others with a slower one.
Floor. Men have more muscle mass and less body fat. This means that they have a higher basal metabolic rate.
Age. As you age, your basal metabolism slows down. After 20 year old age, every ten years this figure decreases on average by 2%.
Weight. The greater a person's weight, the greater the SBI.
Body surface area. This is the ratio of your height and weight. The greater the total surface area of ​​your body, the higher your BVR.
Tall, thin people have more BOO. If we compare a tall and short person of the same weight who consume the same number of calories to maintain their weight, we can see that after a year the taller person's weight will remain the same, but the shorter person's weight may have increased by about 7 kg.
Body fat percentage. The smaller it is, the larger the SBI. It is the lower percentage of body fat in men that is the reason why their basal metabolic rate is higher than that of women.
Diet. Fasting or sharply reducing caloric intake can reduce basal metabolic rate by 30%. Low-calorie diet for weight loss may lead to lower BOO by 20%.
Body temperature. When core body temperature increases by half a degree, BOO increases by approximately by 7%. The higher the body temperature, the faster chemical reactions occur in the body. Therefore, the BOO of a patient with a temperature of 42°C will increase approximately by 50% .
External temperature. Ambient temperature also affects basal metabolism. Exposure to cold temperatures increases BOO because the body needs to produce more heat to maintain the required core body temperature. A short stay in high temperature conditions has little effect on metabolism because... the temperature is compensated due to increased heat transfer. But prolonged exposure to heat can also increase BOO.
Hormones. Thyroxine (produced in the thyroid gland) is one of the key regulators of SBI. It speeds up the metabolic activity of the body. The more thyroxine produced, the higher the BOO. If the body produces too much of it (a condition known as thyrotoxicosis), BOO can double in size. If there is too little of it (myxedema), the VOO may decrease by 30-40% compared to the norm. Like thyroxine, epinephrine also increases BOO, but to a lesser extent.
Exercises. Exercise not only affects your weight by burning calories, but also helps increase your basal metabolic rate by increasing muscle mass.

Short-term factors affecting general metabolism

High temperature caused by inflammation, high levels of stress hormones in the body, and an increase or decrease in ambient temperature lead to an increase in BOO. Fasting, starvation or malnutrition reduces BOO. Reduced BOO may be the only side effect of the diet. A low-carb diet will not be as effective as one combined with physical activity.

Daily metabolism

The first step towards creating your own diet is to calculate how many calories do you burn per day? , i.e. Your total daily energy expenditure in calories. Knowing this value will begin the formation of your proper nutrition. Physiologists William McArdle and Frank Kachi found that the average daily energy expenditure for women in the United States is 2000-2100 calories th per day, and for men - 2700-2900 per day. But this is an average, the number of calories burned can vary significantly. For example, for athletes or people actively involved in sports, this figure will be higher. Some triathletes and athletes with extremely high loads require at least 6000 calories every day and even more!

Methods for determining calorie needs

There are various formulas you can use to determine your daily calorie needs. They take into account age, gender, height, weight, lean body mass and activity level. Any formula that takes your lean body mass (LMB) into account will give you the most accurate estimate of your energy expenditure, but even without taking into account your lean body mass (MBM), you can still get fairly accurate information.

A quick and easy method for determining calorie needs is to calculate based on your total body weight.
Fat Burning: 26-29 calories per 1 kg of body weight
Weight maintenance: 33-35 calories per 1 kg of body weight
Weight gain: = 40-45 calories per 1 kg of body weight

This is a very simple way to help you estimate your calorie needs. But there are also obvious disadvantages to this method, because it does not take into account activity level and body composition. Extremely active people may require many more calories than this formula indicates. In addition, the greater your muscle mass, the greater your calorie needs will be.

Because it does not take into account obesity, the formula may overestimate caloric needs for overweight people. For example, a 50-year-old woman who leads a sedentary lifestyle weighs 117 kg and her total body fat is 34%. She will never be able to lose weight by eating 3,000 calories every day.

Calculations based on basal metabolic rate

A much more accurate method of calculation is to determine BMR (basal metabolic rate), which uses several factors, including height, weight, age and gender. BOO is then multiplied by activity level to determine daily caloric needs. As a reminder, BOO is the total number of calories your body needs to function normally at rest. This includes heartbeat, breathing, digestion of food, creation of new blood cells, maintaining the desired body temperature and all other metabolic processes in your body. In other words, your BOO is all the energy used to keep the body alive. About 2/3 of your daily calorie requirement is BOO. The intensity of general metabolism can vary significantly from person to person, depending on genetic factors. If someone says that they can eat anything and not gain weight, this means that this person has a hereditary high metabolic rate.

BOO is lowest during sleep, when the body is not processing food. It is worth noting that the greater your lean body mass, the greater your BMR. This is very important information if you want to lose weight. The more muscle you have, the more calories you will burn.

Muscle is a metabolically active tissue, and even maintaining a constant mass requires a lot of energy. Obviously, one great way to increase your basal metabolic rate is through bodybuilding, i.e. workouts aimed at growing and strengthening muscle mass.

Harris-Benedict formula (BOO based on total body weight)

The Harris-Benedict equation is a calorie-calculating formula that takes into account height, weight, age, and gender to determine basal metabolic rate (BMR). This makes it more accurate than determining calorie needs based on total weight alone. The only criterion that is not used here is muscle mass. Thus, this equation will be very accurate for everyone except people with excessive muscle mass (calorie needs will be underestimated) and obese people (calorie needs will be overestimated).

Men: BOO = 66 + (13.7 x weight in kg) + (5 x height in cm) - (6.8 x age in years)
Women: BOO = 655 + (9.6 x weight in kg) + (1.8 x height in cm) - (4.7 x age in years)

Example:
Are you a woman
You are 30 years old
Your height is 167.6 cm
You weigh 54.5 kg
Your BOO = 655 + 523 + 302 - 141 = 1339 calories per day

Activity coefficients:
Sedentary lifestyle = SBI x 1.2 (little or no exercise, sedentary work)
Light activity = BOO x 1.375 (light physical activity/sports 1-3 times a week)
Moderate activity = BOO x 1.55 (quite a lot of physical activity/sports 3-5 times a week)
High activity = BOO x 1.725 (high physical activity/sports 6-7 times a week)
Very high activity = BOO x 1.9 (very high daily physical activity/sports and physical work or training 2 times a day, for example, marathon, competitions)

Example:
Your BOO 1339 calories per day
You have a moderate level of activity (exercise 3-4 times a week)
Your activity factor is 1.55
Your daily calorie requirement = 1.55 x 1339 = 2075 calories per day

Ketch-McArdle Formula (Lean Body Mass Based BBM)

If you have checked and know exactly what your body's muscle mass is, then you can get the most accurate BOO estimate. The Ketch-McArdle formula takes muscle mass into account and is therefore more accurate than a formula that only takes total body mass into account. The Harris-Benedict equation has separate formulas for men and women because men tend to have more lean body mass (MBM). Since the Ketch-McArdle formula is based on MMT, it applies equally to both men and women.

Basal metabolic rate (men or women) = 370 + (21.6 x lean body mass (MBM) in kg)

Example:
Are you a woman
You weigh 54.5 kg
Your total body fat is 20% (10.9 kg fat)
Your body weight minus fat = 43.6 kg
Your BOO = 370 + (21.6 X 43.6) = 1312 calories
To determine your daily calorie requirement (DCR), you simply multiply your DCR by your activity factor:

Example:
Your SBI 1312 calories
You have a moderate level of activity (exercise 3-4 times a week)
Your activity factor is 1.55
Daily calorie requirement = 1.55 X 1312 = 2033 calories

As you may have noticed, the difference between the values ​​​​calculated using the two formulas is small (2075 calories versus 2033 calories), since the person we considered as an example has an average body size and composition. The main advantage of a calculation that takes into account muscle mass is that it more accurately shows the daily calorie requirement (DAR) for very muscular or, conversely, obese people.

Adjust your calorie intake to suit your goal

So, you already know your SPC. The next step is to adjust the number of calories you consume depending on your goal. The math behind calorie balance is very simple. To maintain your weight at the current level, you need to adhere to the SPC. If you want to lose weight, you need to create a calorie deficit in your body, to do this, reduce your BAC (or consume the same amount of calories, but increase physical activity). If your main goal is to gain weight, you need to increase the number of calories you consume. The only thing that differentiates weight loss and weight gain diets is the amount of calories consumed.

Negative calorie balance is the most important factor for weight loss

Counting calories is not only important, it is the most important factor in losing weight. If you consume more calories than you expend, you will not lose weight, no matter what foods you eat. Some foods are stored as fat more easily than others, but always keep in mind that too much of anything, even “healthy foods,” will be stored as fat. You cannot change the laws of thermodynamics and energy balance. In order to burn fat, the body must be in a calorie deficit. This will force your body to use stored fat to fill energy deficits. 0.5 kg of body fat contains 4,500 calories. If you spend a week through diet, exercise, or a combination of both, you will create a deficit in 4500 calories, you will lose 0.5 kg weight. If in a week the deficit is 9000 calories, you will reset 1 kg. A calorie deficit can be created through diet, exercise, or best of all, a combination of both. Since we've already calculated the calorie reduction from exercise (using the activity factor), the deficit we're talking about is exactly what the diet would produce.

Calorie deficit limit: what amount can be considered the maximum permissible?

Everyone knows that if you reduce the number of calories consumed too much, your metabolic rate will slow down, the thyroid gland will reduce the production of hormones and muscle mass will begin to decrease. How much should you reduce your calories then? There is definitely a limit below which cutting calories can have negative health effects. For weight loss, it is recommended to reduce the number of calories consumed compared to the SPC by at least 500, but no more than 1000. For some people, especially thin people, 1000 calories may be too much of a deficit. The American College of Sports Medicine does not recommend caloric intake below 1,200 per day for women and 1,800 per day for men. But even these quantities are very small. It is best to determine a safe level of calorie deficit based on your weight and DA (daily calorie requirement). Reducing your calorie intake by 15-20% from SPK is a very good start. Sometimes a larger deficit may be needed, but then it is best to increase your exercise while maintaining the same caloric deficit.

Example 1:
Your weight is 54.5 kg
Your SPK is 2033 calories
Calorie deficit for weight loss - 500
Your optimal calorie intake for weight loss: 2033 - 500 = 1533 calories
Example 2:
Your calorie deficit for weight loss is 20% of your BAC (20% of 2033 = 406 calories)
Your optimal calorie intake for weight loss = 1627 calories

A Positive Calorie Balance Is Necessary to Build Muscle

If you want to build muscle and become more muscular, you must consume more calories than you burn in a day. But this is impossible without bodybuilding. Only in this case will the excess calories be used to create new muscle tissue. Once you have determined your BAC, the next step is to increase your calories enough to allow you to gain weight. This is the basic law of energy balance: to build lean body mass, you must eat a diet with a positive balance of calories.

The starting point for weight gain should be an increase in BOP by 300...500 calories per day. Or you can add 15-20% of your SPK.

Example:
Your weight is 54.5 kg
Your SPK is 2033 calories
In order to gain weight, you need 15-20% more calories than your BAC = 305...406 calories
Your optimal calorie intake for weight gain is 2033 + (305...406) = 2338...2439 calories

Change your calorie intake gradually

It is not recommended to make drastic changes to your diet. If, after calculating your daily calorie requirement (DAC) and adjusting it based on your goal, you realize that the required amount of calories is significantly different from your current level of consumption, then you definitely need to change the amount of calories gradually. For example, you have determined that your optimal daily calorie intake should be 1900, but previously your level was only 900 calories per day. If you suddenly increase your calories, your metabolism will slow down. A sudden jump to 1900 calories per day can cause an increase in body fat, because your body is already accustomed to consuming less and a sudden increase in calories will contribute to obesity. The best way is within 3-4 weeks gradually increase the number of calories you consume from 900 to 1900. This will allow your body to adapt and speed up your metabolism.

Measure your results and adjust your calories

The calculations that will help you find the right amount of calories to consume are very simplified and are needed only so that you know where to start. You will need to monitor your progress closely to ensure that this is the right level for you. To make sure you're on the right track, you'll need to monitor your calorie intake, body weight, and body fat percentage. You need to monitor your body weight and body fat percentage to see how your body reacts to dietary changes. If you see that you are not getting the desired results, adjust the number of calories you consume and your activity level. The main thing is not to cut calories too much to lose weight. The best option is to slightly reduce the number of calories and increase daily energy expenditure by increasing the amount, duration and intensity of physical activity.

Good luck on your path to an ideal figure!

When considering creating your own meal plan for weight loss or muscle gain, people start counting calories. Previously, we already considered that to gain weight, you need about 10% excess, and to lose weight, about 10% deficit of total calorie expenditure. If we can calculate the calorie content of jogging and heavy exercise, then how can we calculate the basal metabolism? To do this, you need not only to know the formula, but also to know the essence of the things that we will try to understand.

General information

So, basal metabolism, also known as basic metabolism, is all the processes that constantly take place in our body. They also include:

• Maintaining body temperature.
• Normal brain functioning.
• The work of muscle tissue.
• The functioning of the immune system.
• Secretion of hormones.
• Tissue regeneration.
• Secretion of digestive enzymes.
• Blood supply.
• Breath.
• Transportation of various substances within the body.

And this is not a complete list of what happens in our body during life.

All these background processes can be compared to what happens in the Windows Task Manager. Even there, if you look, there are about 20-30 processes that regulate the operation of the computer. For all these processes, the body releases energy, which is what is considered basal metabolism.

Stages and levels

If you dig a little deeper into the processes of basal metabolism, you will notice that they all proceed heterogeneously. There are certain levels and stages of basal metabolism. Considering each of them, we can better understand the processes and biochemistry that take place in our body. Thanks to this, you can not only correctly calculate the basic needs of the body, but also correct them, shifting the anabolic-catabolic scales in the right direction.

And yet - why do you need to know the basic processes of basal metabolism for weight loss? When we limit calorie intake to a certain level, basal metabolic processes remain virtually unchanged. Everything goes as usual. However, a person already feels a loss of strength due to the fact that the residual energy obtained from food is not enough for him. If you limit caloric intake below the level of basal metabolic consumption processes, then everything will become somewhat worse, since after 24 hours, the body will perceive the whole situation as a hunger strike, and therefore begin.

In this case, the following processes await a person.

1. Extreme slowdown of metabolic processes.
2. Offset.
3. Changes in the level of muscle tissue in the body.

But this will be only the first stage of a violation of the main metabolism, which will occur when trying extreme weight loss or fasting. At this level, basal metabolism can retain energy for up to 3 or 4 days. Then processes will occur that will irreversibly affect health:

1. The breakdown of the internal walls of organs by stomach acid.
2. Complete transition to adipose tissue.
3. Continued optimization of resources by changing the composition of ligaments and joints.
4. General metabolic disorder.

This will be followed by disturbances in the body’s excretory system, which will also not end very well.

If the caloric intake remains insufficient to maintain the level of basal metabolism, then everything will end in death.

At the same time, in normal mode, what are the main metabolic processes in the body? And why is it important to know the minimum caloric content that is used to maintain the life support of the body.

1. Digestion of food - this stage is the easiest to start with, since along its path you can follow the main energy levels that follow in the main metabolism. About 20% of the energy calculated in basal metabolism is spent on it.
2. Transport of glucose in the blood through tissues.
3. Breakdown of trace elements into simple amino acids.

This is only the first stage of basal metabolism at a normal level and metabolic rate. The next stage is the distribution of energy across various tissues. Further, depending on the availability of its own reserves and the frequency of food intake, the body either uses its own reserves (expressed in the form of glycogen) or consumes glucose supplied with food.

Well, the last process occurring in the body when considering basal metabolism is the process of removing waste tissue. At this point, the main metabolic end products are eliminated.

The main metabolic products are:

1. Secondary breakdown products formed during digestion.
2. Secondary urinary fluid used to normalize water-salt balance.
3. Spent cells of the body.
4. Waste products (toxins, etc.)

If there is a deficiency and violation of calorie intake, the body will try to extract energy from these waste tissues, which will lead to poisoning. Therefore, maintaining normal calorie content is not only the key to normal metabolic processes in the basal stage, but also the prevention of poisoning of the body with waste toxins, which can also lead to very serious consequences.

The essence

Basic metabolism is the basis for calculating caloric intake in the body. All processes in the body require energy. And in order not to count each process separately, it was decided to use a weighted average value, which, with some adjustments, is used to calculate the basic calorie consumption in the body.

In the most simplified form, people subtract about 800 kcal for basic needs. However, in this case, many factors are not taken into account, which can significantly slow down weight loss. Therefore, the formula for calculating basal metabolism is usually used:

Net weight of a person* 2.35 + number derived from Rubner’s surface law/24. All this needs to be multiplied by the number of waking hours per day.

There is another formula.

Weight * 1.78 +300. The simpler formula for basal metabolism has small errors due to the fact that it uses fat calculations. Hence, it is only suitable for people of average build.

Important: you need to understand that calculating your basal metabolic rate is not fundamental for most people. In particular, this is why the formula in which only 800 kcal is allocated for basic human needs has taken root. It is necessary to calculate basal metabolism only in cases where the classic calorie deficit/excess formulas do not give a noticeable result. For example, for those that are very sensitive to changes in calorie content.

Rubner's surface law

Another interesting factor that affects the rate and expense of basal metabolism during the day is Rubner's surface law. According to this law, people with more surface area waste more surface area. What follows from this? Two main conclusions can be drawn from this:

1. Tall people need twice as many calories to maintain basic metabolic processes in the body.
2. Overweight people lose weight faster because they very often incorrectly calculate the level of their own basal energy metabolism, therefore they spend more calories than expected.
3. People with smaller volumes find it much easier to gain weight since they can add fewer calories to their daily diet.

How does this work?

The thing is that our body spends a certain amount of energy to maintain heat levels. When we are sick and the temperature rises, the body spends more energy. When we are tired, our body temperature drops. The body needs to warm up about 75 kilograms of weight in proportions 1.7 * 0.8. Based on this, we can calculate the heat capacity of the body, which is about 2000 joules per kilogram of body per hour. Or, in terms of calorie content, it is 0.5 kcal per kilogram of body and liter of volume. Those. The average person spends about 300 kcal per day just on heating themselves. The error for tall and overweight people is actually not as big as it seems - only +- 100 kcal per day. However, when following extreme mono-diets, this factor must be taken into account.

Another important feature of the Rubner surface is that heating is carried out depending on the external temperature. Therefore, in winter we need 200-300 kcal more per day than in summer, and this is due solely to the ambient temperature.

Factors affecting metabolic rate

Basic metabolism is regulated by several main factors that determine its course. Knowing these factors, you can use various tricks to adjust the processes of basal metabolism. This can help not only in the fight against extra pounds, but also to stabilize metabolic processes at the entrance and exit from complex diets.

1. Metabolic rate. The rate of calorie expenditure to maintain basic functions initially depends on it. By artificially slowing down or speeding up metabolism, you can get a significant boost of energy, or save on your diet.
2. Normality of passing stages. Depending on what food you eat, how you sleep, etc., the normality of individual levels of basal metabolism depends.
3. Changes in water-salt balance. The course of basal metabolism depends on the amount of fluid. All this is connected with optimization processes and fluid consumption for vital processes.

In addition, there are objective processes that affect basal metabolism that a person cannot control.

1. Hormonal background.
2. The performance of the thyroid gland.
3. Heart rate.
4. Accumulation of cholesterol in the blood.

Not only the speed of ongoing metabolic processes, but also human health in general depends on all this.

Additional Factors Changing Basal Metabolic Rate

Factors that influence metabolic processes in the human body and, therefore, can change the level of basal metabolism in one direction or another deserve special consideration.

Factor	The essence of the factor	Effect on basal metabolism
Caffeine	Caffeine
Nicotine	Accelerates the force and speed of contraction of the heart muscle, accordingly causes an increase in blood flow in the body and, as a result, accelerates metabolic processes in the human body.	Increases calorie consumption in the basal stage by several orders of magnitude.
Exercise	Accelerates the force and speed of contraction of the heart muscle, accordingly causes an increase in blood flow in the body and, as a result, accelerates metabolic processes in the human body.	Increases calorie consumption in the basal stage by several orders of magnitude.
Increasing caloric intake	With an increase in caloric intake, the body begins to spend more energy on digesting food, which in turn forces it to synthesize digestive enzymes - and as a result, spend more resources.	Increases calorie consumption in the basal stage by several orders of magnitude.
Increasing the number of meals	With an increase in the number of meals, the body optimizes all basic processes, which leads to their acceleration, and therefore an increase in consumption at the basal level.	Increases calorie consumption in the basal stage by several orders of magnitude.
Lack of sleep	With a lack of sleep, the body, with a general decrease in performance, tries to optimize resources, which increases the production of the norepinephrine group of hormones, which lead to an increase in calorie consumption while slowing down metabolic processes.	Slight increase.
Healthy 8 hours sleep	In 2 4-hour cycles, the body completely rebuilds the basic systems of the body, which means it spends less energy on maintaining basic processes during the day.	No effect.
Physical inactivity	With physical inactivity, metabolic processes slow down. However, at the same time, the level of basal metabolism remains stable.	No effect.
Reception of energy drinks	Accelerates the force and speed of contraction of the heart muscle, accordingly causes an increase in blood flow in the body and, as a result, accelerates metabolic processes in the human body.	Increases calorie consumption in the basal stage by several orders of magnitude.
Taking various medications	Depending on the type of medication, side effects may affect metabolic processes differently.	Depends on the type of medication.

Bottom line

Naturally, if you want to correctly calculate your nutrition, you need to know what basal metabolism is and how to calculate it. However, in fact, all these simplified formulas and indications do not always reflect the essence. If you seriously intend to count everything and are a professional athlete, then instead of the indicated formulas, it is better to simply add individual processes to the table of energy expenditure (which is spent on various activities, from simple walking to your training).

And although the editors do not believe that such an accurate calculation is necessary for normal nutrition, understanding the basics of basal metabolism allows you to avoid mistakes and harm your body during extreme weight gain or loss. This is especially important for novice athletes and women, for whom the level and speed of basal metabolism are decisive in their ability to give birth to a child.