Basal Metabolic Rate calculates the amount of energy consumed by your body when at rest. In other words, it is the total amount of energy required by your body to perform basic tasks such as breathing, circulating, cell production, nutrients processing, and others that help sustain your body.
Table of Contents
- BMR Charts
- A deep understanding of BMR
- The relationship between metabolism and BMR
- An understanding of a relationship between BMR and TDEE
- BMR versus Resting Metabolic Rate (RMR)
- History of Basal Metabolic Rate
- How to Calculate your BMR?
- Convenient online BMR Calculator
- Key factors that affect your BMR
- The importance of BMR in weight loss
- Effective ways to improve your BMR
- Foods that are BMR boosters
- Lifestyle tips to enhance BMR
|Men’s average BMR based on Heights|
|Height (feet)||Average BMR||Mean|
|Women’s average BMR based on Heights|
|Height (feet)||Average BMR||Mean|
A deep understanding of BMR
Basal Metabolic Rate calculates the minimum amount of energy consumed by your body when the digestive system is inactive. In other words, it is the total number of calories required by your body to perform basic tasks such as breathing, circulating, cell production, nutrients processing, and others. When your body is resting, only vital organs, such as the lungs, heart, liver, kidneys, intestines, nervous system, sex organs, muscles, and skin, can use energy in this state.
In other words, BMR doesn’t account for the amount of energy used for any physical activities, such as watching TV, taking a shower, doing chores, reading, walking, exercising, etc. Your activity levels demand more energy. Intuitively, the more activities performed, the more energy required by your body.
The relationship between metabolism and BMR
Metabolism is a process occurring within your body composed of countless chemical reactions to break down nutrients from foods, assisting with body development and repair. Thanks to the metabolism machine, your body can operate normally, and your life is sustained. The reason we care about BMR measurement is that it is an indicator of your metabolism.
Metabolism is a complex process that is composed of two parts: Catabolism and Anabolism.
Catabolism is the process by which food components (such as carbohydrates, proteins, and dietary fats) are broken down into simpler forms that can then be utilized to provide energy and the essential building blocks needed for body development and repair.
Anabolism is the process by which our bodies are constructed or restored. Anabolism necessitates energy, which you obtain from our food. When you consume more nutrients than your body needs for daily anabolism, the extra nutrients are typically retained as fat in your body.
Generally speaking, a high BMR indicates an effective metabolism. A person who has fast metabolism tends to lose weight more quickly.
An understanding of a relationship between BMR and TDEE
TDEE stands for Total Daily Energy Expenditure. While both BMR and TDEE tell you the number of calories your body needs, they are slightly different. TDEE gives you the measurement of total energy consumed for not only sustaining function but also every single activity during a day.
In order to calculate TDEE, you must know BMR because your BMR takes up a significant portion of your TDEE. Generally, body upkeep accounts for up to 70% of total energy (calories) burned by most people per day. Physical activities varying by your daily activity levels account for up to 20%. The last 10% is made up of the thermic effects of foods, which, simply put, is the energy consumed through the ingestion and digestion of foods.
TDEE usually is calculated by determining the basal metabolic rate (BMR) and multiplying it by the required amount of physical activity (PAL). The table below is for reference.
|Sedentary: Little or no exercise||1.2|
|Light exercise 1-2 times/week||1.375|
|Moderate exercise 2-3 times/week||1.55|
|Hard exercise 4-5 times/week||1.725|
|Physical job or hard exercise 6-7 times/week||1.9|
BMR versus Resting Metabolic Rate (RMR)
Another term that is frequently used interchangeably by fitness experts is Resting Metabolic Rate. The amount of calories burned by your body at rest is calculated by your resting metabolic rate. The resting metabolic rate is usually estimated in the morning before eating or exercising and after a whole night’s sleep. As can be seen, Resting Metabolic Rate and Basal Metabolic Rate are pretty similar. In fact, your Resting Metabolic Rate should be a near approximation of your Basal Metabolic Rate, which is more commonly used.
You need to keep in mind that the calculation of RMR requires fewer restrictions than BMR. You don’t need to fast, rest for an extended time, or be monitored in a controlled environment for an RMR test. Due to the more lenient testing, RMR tends to give a less accurate measurement of your primary energy need.
Both BMR and RMR are critical for developing a balanced diet that provides your body sufficient energy. They also play a crucial role in making weight loss feasible. Please read on to learn about the importance of BMR.
History of Basal Metabolic Rate
One of the first equations to be introduced was the Harris-Benedict Equation. It was updated in 1984 to make it more reliable, and it was used until the Mifflin-St Jeor Equation was adopted in 1990. The modified Harris-Benedict Equation has been found to be less precise than the Mifflin-St Jeor Equation.
Later on, the Katch-McArdle Formula is introduced. It is unique in that it measures resting daily energy consumption (RDEE) and takes into account lean body mass, which neither the Mifflin-St Jeor nor the Harris-Benedict Equations do.
Out of the three formulas, Mifflin-St Jeor’s equation is believed to be the most accurate. However, if you know your body composition, fat percentage, and lean mass, Katch-McArdle Formula is the most highly recommended.
How to Calculate your BMR?
It is worth noting that your BMR is calculated for a period of 24 hours or within a day. More importantly, to achieve accurate BMR calculation, you need to undergo a restrictive clinical process, including full 12-hour fasting, an 8-hour sleep prior to the test, being monitored in a dark, temperature-controlled environment, and tested in a reclined position.
The amount of oxygen and carbon dioxide a human breathes in and out is used to calculate BMR. Calorimetry is the term used by experts to describe this form of study. It is a method of calculating the number of calories burned by a person’s body. Other factors such as age, gender, weight, height, and body composition are taken into account to obtain the most personalized measurement.
Below are three formulas to calculate BMR:
Mifflin-St Jeor Equation:
For men: BMR = 10W + 6.25H – 5A + 5
For women: BMR = 10W + 6.25H – 5A – 161
Revised Harris-Benedict Equation:
For men: BMR = 13.397W + 4.799H – 5.677A + 88.362
For women: BMR = 9.247W + 3.098H – 4.330A + 447.593
Katch-McArdle Formula: BMR = 370 + 21.6(1 – F)W
W: body weight in kg
H: body height in cm
F: body fat in percentage
Convenient online BMR Calculator
If those equations appear intimidating for you to use, you may love to check out the online BMR calculator. Simply plug in your age, gender, weight, and height, you will get your estimated BMR in an instant. The online tool is widely available and very convenient. Plus, it is very time-saving because you don’t have to go through strict monitoring and extensive fasting. The effectiveness is relatively limited because it only provides an approximate measurement.
BMR can be estimated using equations and web calculators. You should, however, consult your healthcare practitioners if you want more reliable outcomes.
Key factors that affect your BMR
Some families have faster BMR than others, and some genetic defects impair metabolism as well. Hormonal imbalances like hypothyroidism and hyperthyroidism will also adversely affect your metabolism and thereby lowering your BMR. It is true when people say fast metabolism runs in the family.
As you age, your metabolism decreases due to muscle tissue deterioration, as well as hormonal and neurological shifts. As you may guess, your BMR also begins to decline. Metabolic age is a term referring to this concept. If your metabolic age is older than your actual age, it means you need to enhance your metabolic rate.
Because of the energy demands of development and the extra energy required to sustain the body temperature, babies and children have higher energy demands per unit of body weight. Their metabolic rate increases as they age. Basal metabolism increases when an infant matures and peaks around the age of 16 or 17, during which it usually begins to decline.
When discussing how sex differences affect metabolism and thereby BMR, you want to look closely into the differences in muscle mass, fat percentage, and physical activity level between males and females.
Men tend to have larger BMR because they generally have larger body sizes and more muscle mass. Furthermore, because they naturally have more significant amounts of testosterone in their bodies than their gender counterpart, it is easier and quicker for them to build and sustain muscle mass.
For women, their bodies are generically constructed to prepare for specific activities such as pregnancy and breastfeeding. Those activities demand energy to be stored in the form of fat, meaning that fewer dietary intakes are transformed into muscle mass. As a result, female bodies are more likely to have slower metabolism and BMR than males.
The size of your body is another significant factor in your BMR. Adults with bigger bodies have more metabolizing tissue and a higher BMR. Intuitively, a person with a larger body needs more energy to carry and operate their body.
Your body size, particularly weight and height, is proportional to your BMR measurement. You will have a higher BMR than a person who is shorter and lighter than you. If you and the person have the same height, the one with high weight will have a larger BMR.
Lean mass is a considerable determinant of BMR level. Research shows that a body composition with a larger percentage of muscle expends more calories. At rest, each pound of muscle burns about six calories a day, according to estimates. That’s about three times the number of calories burned by a pound of fat, which burns only two calories per day.
If you gain 5 pounds of muscle while losing 5 pounds of fat, you will burn an additional 20 calories per day. While your weight remains the same, your BMR is boosted because your body demands more energy to operate.
An indirect way muscle mass can enhance BMR is through how muscle is built and maintained. In order to gain muscle, you have to commit to intensive strength training and weight-lifting. Increasing physical activity level and intensity, logically, will burn more energy and improve your BMR.
The fat percentage
The fat proportion has the opposite effect to BMR in comparison with muscle mass. A high percentage of body fat translates into a less lean body and, therefore, lower BMR. Not only is it because fat burns fewer calories than lean muscle, but it is also because fat is a form of energy storage.
Your body is an intelligent machine. It ingests and digests foods for your growth and repair. Moreover, it also stores energy for future use if it senses that you won’t have infrequent access to foods. Basically, excessive energy will not be burned but stored to be used when needed. Thus, your BMR will be lowered.
Physical activity level
Physical activities are a big part of BMR because it affects your metabolism, which then influences your BMR measurement.
You burn energy when doing physical activities, ranging from walking, sitting, standing, sleeping to playing sports, exercising, working, and so on. Virtually every activity requires burned energy. Generally speaking, if you are highly active, you are more likely to have better metabolism and higher BMR than people who are less active.
Living in cold weather is proven to boost your metabolism and increase your BMR. It is because more energy will be needed to regulate your body’s temperature and to keep you warm.
Nutrition definitely plays a crucial role in shaping your metabolism and BMR. It is very true that you are what you eat. A well-balanced meal with a big portion of protein, healthy fat, and fiber will improve your BMR. On the other hand, a lack of essential nutrients will cause low BMR. For instance, Iodine deficiency lowers thyroid activity and delays metabolism.
Supplements are another external factor that can significantly influence your BMR. There are certain supplements you can take to boost your metabolism, such as vitamin B, iron, magnesium, and so on.
Take vitamin B, for example. Besides being a prime contributor to enhancing the nervous system, vitamin B aids in fat, protein, and carbohydrate synthesis and the conversion of food into energy. Another excellent example is fiber, which can be obtained from vegetables or supplements. Fiber is like foods of your metabolism, nurturing and growing it.
It may be interesting to think that your stress level can impact BMR, but there is a critical correlation between them.
Stress is an inevitable part of adulthood, which can stem from the pressure from the workplace, schools, family, friends, to name but a few. When you are stressed out, you put your body under the pressure of coping with stress. Thus, more energy is placed on your stress coping mechanisms rather than the digestion of foods and the generation of energy fueling your body.
Scientifically speaking, the sympathetic nervous system is activated in response to stress, as is the release of epinephrine and cortisol. These hormones can decrease insulin sensitivity in the long run. Insulin resistance accounts for high blood pressure, obesity, lipid disorder, heart diseases which contribute to metabolic disorder.
Pregnancy is an essential factor changing BMR in female bodies. Among the many adaptations that the mother’s organs make during pregnancy to satisfy the demands caused by the expansion of her own breast and genital tissues, as well as the development of the conceptus, are metabolic changes.
Furthermore, female bodies must be built to meet the demands placed on their body during pregnancy, childbirth, and the postpartum period. Normally, the metabolic rate increases after the third month of pregnancy and will continue till the delivery date. The rate of change is proportional to the size of the fetus and the level of physical activities. Weight gain and food craves are common for pregnant women.
Infection and illness
In order to understand how minor illnesses such as fever affect metabolism, you have to understand how insulin production. Glucose or blood sugar is broken down from carbohydrates after you eat. When you are ill, your body speeds up the production of glucose, which temporarily increases metabolism and BMR. However, you must be aware that slow metabolism can be a result or sign of diseases.
The importance of BMR in weight loss
Note that the weight loss being mentioned here is the result of fat loss, not water loss. When calories input is less than calories output, weight loss will occur. Calorie deficit enables your body to use up the stored energy in the form of fat, thus facilitating the process of fat loss.
Knowing your BMR will help you calculate your average daily energy consumption. As mentioned above, your TDEE (Total Daily Energy Expenditure) is the sum of BMR and energy expended by activity thermogenesis and thermic effect of foods. To lose weight, you must create a caloric deficit, which means you must either decrease your caloric consumption below your Total Daily Energy Expenditure or increase your total daily energy expenditure through physical activities.
Take athletes for an illustration. To lose one pound in one week, athletes can reduce their daily caloric consumption by 500 calories a day. The caloric deficit can be produced by increased exercise, diet, or a combination of the two.
Increasing your metabolism allows you to consume more foods rather than going into an exhausting and restrictive diet. It is the light at the end of the tunnel for many people who wish to lose weight without giving up the foods they love or having to eat less. It is because fast metabolism is synonymous with high BMR, which means a more considerable amount of calories you need to survive.
Below are three valuable ways to speed up your metabolism and boost BMR.
Effective ways to improve your BMR
BMR can change slightly over time in response to some conditions:
Building muscle mass
Strength training is fantastic to increase your BMR for a more extended period of time by changing the body’s composition. It is analyzed above that muscles require more energy to maintain than fat. By weight lifting and intensive strength training, you will build muscles and grow lean mass, helping boost your BMR.
Once your muscles are developed, you want to lift heavier and train more frequently to maintain muscles. You will be able to lengthen your workout sessions, improving your body resistance. Therefore, more calories will be burned in the long run. I strongly suggest bend press, shoulder press, leg press, deadlift, squat, lunges, pushup, tricep dips for fast muscle building. Remember to include weight and resistance bands to increase the effectiveness of those exercises.
Keep in mind that weight loss can decrease your BMR because BMR is heavily dependent on weight. If you weigh less, your body won’t need as much energy to carry it or perform tasks before weight loss. As a result, weight loss without muscle growth will only slow down your metabolism.
Physical activities are a massive part of your daily life. Whether you are aware or not, you perform various categories of physical activities, from transporting, occupational activities, house chores to leisure sports and workouts. Physical exercise can be further classified based on its frequency, duration, and intensity.
Depending on your age, health conditions, and preferences, a duration of 30 minutes spent on exercises is typically recommended. It can be a brisk 30-minute jog at a nearby park, a treadmill, a HIIT or high-intensity interval training, and sports such as soccer, tennis, and volleyball. Those types of activities will increase your breathing, heart rate and cause sweating.
For busy individuals who find it challenging to afford time for exercises, they are encouraged to stay active through house chores and increase the standing time. In comparison with weight-lifting, cardio activities are not as effective and may result in limited impacts on your BMR.
Thermic effects of foods
Since you use energy to eat, absorb, and metabolize the foods you just consumed, the BMR increases after eating. The increase begins shortly after you begin eating and lasts for two to three hours. It is worth noting that not all types of foods require the same amount of calories to be digested. Please take a look at the below table to understand the impacts of different micronutrients on BMR.
|BMR Percent Raise by Macronutrients|
As shown from the table, adding more proteins to your meal is an effective way to increase the thermic effect. Taking advantage of macronutrients and their impacts on BMR, you can design a balanced diet that will facilitate weight management wonderfully.
Foods that are BMR boosters
Let us focus on macronutrients, which are dietary fat, carbohydrates, and proteins. Among three macronutrients, proteins have the most significant role in shaping your metabolism.
To improve the metabolism, you must eat enough proteins. A diet with sufficient proteins also helps prevent high blood pressure and diabetes. Some common protein-rich foods are chicken breasts, beef, seafood, whole eggs, Greek yogurt, Cottage cheese, and milk. Vegan options you can choose from are lentils, quinoa, oats, beans, almonds, peanuts, and other nuts.
|Protein-rich foods (100 g)||Protein amount|
|A chicken breast without the skin||31 g|
|A whole egg||13 g|
|Greek yogurt||10 g|
|Lean beef||26 g|
|Whole dairy milk||8 g|
|Cottage cheese||11 g|
|Brussel sprouts||3.4 g|
Fats have been demonized as a factor of obesity, heart disease, and weight gain. However, healthy fats are critical for your body to boost metabolism and increase BMR in the long term. Some examples of healthy fat foods are avocados, fatty fish (salmon, tuna), cheese, dark chocolate, nuts, chia seeds, extra virgin olive oil, and coconut oil. Implementing healthy fats to your diet will help you stay full longer, more satisfied, and avoid snacking.
Speaking of carbohydrates, they are essential to provide you energy for task performance throughout your day. Eating sufficient carbs reduces your hunger and craves sugar-high foods, which lead to poor metabolism. Highly recommended carbs are quinoa, oats, buckwheats, chickpeas, beans, beetroots, and bananas.
Let’s move on to micronutrients. B-complex vitamins from legumes, leafy greens, fish, eggs, organ meat, and beef are excellent for a productive metabolism. Besides vitamin D from salmon, egg yolks, soy milk, the mushroom is also believed to increase your BMR.
Interestingly, caffeine which can be obtained from green tea and matcha, is proven to increase BMR and help with weight management. Eating spicy foods, surprisingly, will help burn up to 50 extra calories a day.
Lifestyle tips to enhance BMR
Resistance training and strength training may sound challenging for many people who lead a hectic lifestyle or don’t like to work out. Here are some effortless lifestyle tips that can easily be done to enhance your BMR. Please note that building muscles, especially a combination of a healthy lifestyle and workout, are the resolution to a long-term high BMR.
Never skip meals
Human beings are creatures of habits. Your body depends on regularity to detect hunger and to signal times to fuel energy. If a person eats a lot and then fasts for an extended period of time, the body can burn calories more slowly and store more fat cells. To avoid this tendency, you should eat at regular times.
Consume sufficient calories
Eating too few calories will cause your body’s metabolism to slow down in order to conserve energy. The human body has evolved to detect how often it can be fueled. When your body receives inadequate energy for a long time, it will learn that conserving energy is essential. Imagine that you are stuck in a desert and merely have access to food. Your body will automatically store energy for the future because it doesn’t know when you can eat again.
Some people want to shed weight by skipping meals. However, this may have a detrimental effect on metabolism. Eating unsatisfying meals may also have the same impact.
Divide foods into small portions and more frequent meals
Excessive energy that cannot be burned through physical activities or sustain your body’s biological functions will be stored as fats. By dividing the total amount of daily foods into smaller frequent portions, you will make sure that all energy from the foods gets used up. Having mini-meals also prevent impulsive snacking and avoid insulin spikes, which is detrimental to your metabolism.
Drink plenty of water
Water is essential to life. Drinking enough water is vital to achieving optimal metabolism. Furthermore, scheduling water time to make sure you have enough water is highly recommended for effective weight management. You may wonder why you keep getting hungry even though you just finish eating. There is a high chance that you are just thirsty. So, before you want to grab some snacks or sugar-high drinks, consider drinking a glass of water.
Depending on body types, personal demand, and health conditions, an adult should drink at least 1.5 to 2 liters of water daily.
Get enough sleep
When you don’t get enough sleep, the body produces ghrelin, a hormone that causes hunger. Your body also produces less leptin, a hormone that aids in feeling full or sated. Getting adequate sleep will help keep these hormones in check. This will prevent you from overeating.
Furthermore, sufficient sleeping will keep your stress at a minimal level, thus reducing pressure on your metabolism. In the long run, your BMR will recover and improve.
Manage stress level
Stress is a large contributing factor to a hormone disorder. As your BMR and hormone regulation are closely connected, stress can cause poor BMR. Stress is also linked to poor sleep quality, which can negatively affect metabolism. Disordered eating, which includes nutritional restriction and weight issues, can result in unhealthy eating habits, disrupting metabolism.
Practicing meditation, taking life slowly, and taking time for relaxing self-care are ways you can reduce your stress level, thus making improvements on your BMR and life quality.
What happens if my BMR increases?
Increasing BMR means that your body now needs more energy to sustain life. It means that you have increased the total amount of energy required by your body to perform basic tasks, like circulation, cell production, ingestion & digestion of nutrients, cardiovascular, respiratory, nervous system, and so on. It is a sign that your metabolism has been improved. You will feel stronger, more energetic and find weight management more simple.
What are good BMR scores?
BMR depends on many factors, such as age, gender, weight, lean mass, diets, health conditions, etc. Based on the average body size, the average man’s BMR ranges from 1,600 and 1,800 kCals a day. A BMR of 1,550 kCals per day is typical for women. This, however, is subject to change. I suggest you consult your doctor for an exact BMR.
What happens if I eat less than my BMR?
Eating too few calories causes the body’s metabolism to slow down in order to conserve energy. If this eating habit lasts for a long time, you will have difficulty losing weight. What’s worse, your metabolism will be disrupted, and your BMR will decline as a result.
Will a 1200-calorie diet slow down my BMR?
A diet of 1200 calories a day may be optimal for a child or an adult with a petite body. Moreover, if you are over the age of 40, your average BMR is likely to be just 1,200 kCals per day. There are many factors to an optimal BMR. This measurement is also personalized to each individual. If your BMR is 1500 calories a day and you consume 1200 calories, you will certainly slow down your BMR.
What should I eat to increase my BMR?
Having a protein-rich diet made up of lean meat, seafood, eggs, Greek yogurt, grains, legumes, and nuts is necessary to improve BMR. Adding supplements B and D to your diet will help speed up your metabolism. Spicy foods are, interestingly, another BMR booster.
What types of exercises are effective in increasing my BMR?
The rule to an increasing BMR through physical activities is muscle development. Thus, strength training is highly suggested for effective metabolism and a high BMR. Deadlifts, squats, lunges, shoulder press, leg press, push-up, pull-up are valuable exercises to build muscles. Implementing weights and resistance bands will be even more effective.
What hormones increase BMR?
The thyroid gland produces two hormones that decide the basal metabolic rate, or the number of calories needed by the body at rest: thyroxine, also known as tetraiodothyronine or T4, and triiodothyronine, also known as T3.
What supplements help metabolism?
Supplements that help with metabolism are calcium, vitamin B5, vitamin B6, vitamin B12, vitamin B complex, and vitamin C. Caffeine and catechins in green tea and other products are also excellent for effective metabolism and high BMR.
What are signs of a fast metabolism?
Having little body fat and high body temperature are the most obvious signs of a fast metabolism. If you feel hungry frequently during the day, feel hyperactive, and move your bowels or poop frequently, you are likely to have a good metabolism. They are signs that you may successfully increase your BMR.
What are signs of a slow metabolism?
If you crave sugar and frequently feel bloated after eating, you may have a slow metabolism. Having difficulty with losing weight or gaining weight very quickly are common symptoms of poor metabolism. Having cellulite, cracked skin, hair loss, physical stiffness, fatigue, and a short concentration span often means that you lack essential nutrients and poor metabolism.
The signs of inefficient metabolism are almost the opposite of an optimal metabolism. While a person having good metabolism sweat a lot and quickly, a person having poor metabolism always feels cold.
BMR or Basal Metabolic Rate is closely linked to metabolism. It is the total amount of energy consumed by your body when at rest. BMR is an important measurement that assists with weight management and developing a healthy lifestyle. Minor healthy changes to diets and physical activities can bring substantial benefits to your metabolism and BMR in the long run.
While BMR can be quickly and conveniently obtained from online BMR calculators or equations, it is always best to meet with your doctor and go through a lab test to obtain an accurate BMR.