Basal Metabolic Rate (BMR)

The minimum caloric requirement required to maintain life in an inactive person is called basal metabolic rate or BMR. You might be surprised to know that it is the number of energy (unit in calories) burned through the body in order stay in bed sleeping all day.

The BMR is capable of expending around 70% of the entire calories burned but this number also changes because of some factors. Calories are expended through processes like breathing, the pumping of blood around the body also retaining body temperature. Due to BMR ahead of those burned the body will expend many calories.

The determination of the overall metabolic speed and the total of calories required to retain, reduce or increase weight is influenced by a huge factor, which is the BMR. A grouping of environmental factors and genetic factors are like so:

  • Genetics: several individuals have faster metabolisms; some individuals have slower metabolisms
  • Gender: it is known that has more muscle and decreased body fat fraction. This only means that men have increased basal metabolic rate.  
  • Age: as the individual gets older the BMR is also reduced. By the age of 20 it decreases 2 % per decade.
  • Weight: The heavier you are the higher BMR you have. Like for instance for thin woman their BMR is lower than women who are overweight their BMR is 25% higher.
  • Body surface area: It is an indication of your weight and height. The larger the factor of your Body surface area the higher your BMR is. Individuals ho have higher BMR are thin and tall people. For instance if you evaluate a short person to a tall person which has equal weight and if they both track a calorie-controlled diet to retain weight for the taller individual the shorter individual might gain around 15 pounds within a year.
  • Body fat percentage: Your BMR is higher when you have a low body fat percentage. Men have 10-15% BMR than women because the latter have low body fat percentage.
  • Diet: BMR is reduced when the body experiences hunger or starvation around 30 percent. BMR drops down to around 20% when one is into preventive low-calorie weight loss diets.
  • Body temperature/health: BMR elevate up to 7 percent when the inner temperature of the body increases 0.5C. At higher temperature reactions of chemicals in the body are usually occurring more quickly. Like for instance, a patient that has a fever of 42C will have a BMR of around 50 percent.
  • External temperature: like inner temperature the outer temperature also affects the basal metabolic rate. BMR is increased when the body is exposed in cold temperature in order for the body to retain the inner heat of the body. There is only a modest consequence on the body when it is exposed to hot temperature while it is compensated largely by the increased loss of heat but BMR increases when exposure is prolonged.
  • Glands: The key-BMR regulator that increases the metabolic action of the body is due to Thyroxin, which is created by the thyroid gland. More thyroxin means higher BMR. BMR is doubled when extra thyroxin is created and results to an ailment referred to as thyrotoxicosis. BMR is reduced to around 30-40 percent if not enough thyroxin (myxoedema) is created. Adrenaline also contributes in increasing BMR however to a smaller degree.
  • Exercise: When doing physical exercises BMR is increased by developing extra lean tissue so exercise does not only burn calories. Unlike fat tissue lean tissue is further metabolically difficult. So it is surprising to know that you are burning more calories during sleep.

Temporary Factors Affecting BMR
Increased BMR results from ailments like elevated stages of stress hormones in the body, fever also an increment or decrement in the environmental temperature. Lowered BMR result from hunger, fasting or undernourishment. This can be a cause of a diet followed and nothing else. Decreasing the number of calories being consumed is not as effective as the combination of increased exercise and dieting. This can be compensated with a good effect from increasing exercise and eating a healthy diet.

How to compute basal metabolic rate (BMR)
The total daily energy expenditure (TDEE) and the number of calories you expend in a day is the initial step in planning a personal diet plan. Including all activities and the total amount of calories expended by your body in 24 hours is how TDEE is best described or other simpler terms it is also the "maintenance level". To have an initial reference point when starting your diet you must know your maintenance level. The normal maintenance level for women is 2000-2100 calories a day also the normal for men is 2700-2900 a day in the United States this is stated by exercise physiologists William McArdle with Frank Katch. These are merely averages; caloric outflow can differ extensively and is much elevated for athletes or particularly energetic persons. Several triathletes and ultra-endurance athletes might need as much as 6000 calories a day if not, over merely to keep their weight. Calorie necessities can also differ between if not identical persons because of differences in inborn metabolic rates.

Methods of knowing caloric requirements
There are many diverse equations can be utilize in order to find a caloric maintenance level. The Factors that you need to consider are sex, age, weight, height, activity level and lean body mass. The most precise way to know your energy outflow is done thru an equation that takes into consideration your lean body mass (LBM) but even in the absence of (LBM) you will be able obtain a logically close approximation.

The "fast" method (based on total bodyweight)
A quick and simple way to find out calorie requirements is to make use of the overall existing body weight times a multiplier.
(Fat loss = 12 - 13 calories per lb. of bodyweight)
(Weight gain: = 18 - 19 calories per lb. of bodyweight)
(Maintenance (TDEE) = 15 - 16 calories per lb. of bodyweight)

Even though this is considered as a very simple method it has also its drawbacks due to it does not consider the activity levels or body composition. Tremendously lively persons can want far extra calories than this equation shows. The more lean body mass one obtains, the greater the TDEE will be. This formula may seriously miscalculate the caloric requirements if the person is overweight. For instance, an evenly lively woman who is 50 year old who is 235 lbs. and has 34% body fat will not drop mass on 3000 calories per day (255 X 13 as per the "fast" formula for fat loss).

Equations based on BMR.
Using several factors to verify basal metabolic rate (BMR), will compute a more precise TDEE. These factors include weight, height, sex and age then multiply the BMR by an activity factor to conclude TDEE. The entire quantity of calories the body needs for regular physical functions (not including activity factors) is termed as BMR. Every metabolic method in the body includes breathing, maintaining your heart from beating, creation of new blood cells, digesting food, retaining body temperature and others. In simpler terms, BMR is the entire energy utilized for the necessary processes of life. BMR differs significantly from individual to individual depending on hereditary factors. People have naturally increased BMR when they can eat everything they desire and not at all gaining an ounce of fat. When you are not digesting something and you are sleeping peacefully, BMR is at its lowest. The more your lean body mass is, the more your BMR will become this is very essential to know about. If you desire to drop body fat this very important because additional muscle you contain, the greater calories you will expend. A huge amount of energy is needed to maintain a muscle that is metabolically active tissue. One technique to boost your BMR is to take on weight exercise in order to boost and/or keep lean body mass. It can be believed that weight exercise aids you reduce body fat, even though not directly in this manner.

The Harris-Benedict formula (BMR based on total body weight)
 The calorie equation utilizing the factors of weight, height, sex and age to verify basal metabolic rate (BMR) is called the Harris-Benedict formula. Instead of determining calorie requirements based on overall bodyweight only this is more precise. The lean body mass is the only variable it does not take into account. Except for the very strong this will underestimate caloric requirements and the very overweight, which will overestimate caloric requirements this formula is very precise.

Note: 1 inch = 2.54 cm.
1 kilogram = 2.2 lbs.

Activity Multiplier

Katch-McArdle formula (BMR based on lean body weight)
You can obtain the most precise BMR approximation of all if you identify your body composition and you identify your lean body mass. This formula provided by Katch & McArdle considers the lean mass and in conclusion it is more precise than an equation based on the entire body weight. There is a separate equation for male and female talking about Harris Benedict equation because men usually have greater LBM and this is factored into the men's equation. The Katch & McArdle formula applies to male or female because it considers LBM.

To determine TDEE from BMR, you simply multiply BMR by the activity multiplier:
As determined by both equations the discrepancy in the TDEE is statistically not significant (2075 calories vs. 2033 calories) because the individual that was used as model has a regular body composition and body size.

Regulate your caloric eating according to your objective
The following step is to regulate your calories in accordance to your main objective is to know once you identify your TDEE (maintenance level). To maintain your weight at its present level, you will be able to stay at your everyday caloric maintenance level this is the simple mathematics of calorie balance. To reduce weight you must decrease calorie intake slightly under your maintenance level and you must create this calorie shortage plan with your trainer or dietician or if not you can increase the level of your daily activities and retain your calories. You must increase your calorie intake slightly above you maintenance level. The entire amount of calories needed is the only difference among weight loss programs and weight gain programs.

Negative calorie balance is necessary to drop body fat
While it comes to losing fat the important thing is calories. You will not drop body fat when you eat more calories than increasing the calories you burn and it does not matter what kind and combination of food you take in. Always remember that when you can consume too much even healthy foods it can be stored as fat because some foods get to be stored easily as fat. You cannot supersede the force balance and laws of thermodynamics. You must lessen the intake of calorie to expend fat. If there is a shortage in calorie this will force the body to utilize stored fat to cover up for the shortage. Did you know that in one of stored body fat there is 3500 calories. You will be able to drop a pound if you make 3500-calorie shortage within a week through a diet or exercise or the combination of the two. If you wish to double the pounds you want to drop double up also the calorie deficit. The dietary deficit is a concern because we previously factored in the work out deficit by means of an activity multiplier.

Calorie shortage thresholds: How low is too low?
Reduced thyroid production, decrease in lean mass and slowing down of metabolic speed are a known cause when reducing the amount of calorie intake. So the sole inquiry is that how much deficit do you require? There is a limit or threshold when reducing calorie intake because if there is no limit this will surely result to harmful effects. To trim down your calories by no less than 500, but not over 1000 lower than your maintenance level is the usual rule for calorie shortage for dropping fat. The amount of calorie deficit also depends how large or small a person is because 1000 calories deficit might be too much for a thin person. The calorie levels should not drop lower than 1200 calories a day for female or 1800 a day for male this is suggested by the American College of Sports Medicine (ACSM). But even this calorie levels are tremendously low. To consider for your TDEE or bodyweight is a more personalized method to know the secure calorie deficit. You can start at 15-20% calorie deficit when you are a beginner. In some situation a greater deficit may be needed but the best way to do this is to increment activity level and combine it with a well balanced diet.

weight: 120 lbs.
TDEE: 2033 calories
calorie deficit to drop weight: 500 calories
best caloric ingestion for losing weight: 2033 - 500 = 1533 calories>

calorie deficit to lose weight: 20% of TDEE (.20% X 2033 = 406 calories)
best caloric ingestion for losing weight = 1627 calories>

Positive calorie balance is necessary to increase lean bodyweight

An individual must eat more calories within a day than expending it when you want to increase lean bodyweight and to have more muscle. The extra calorie will be utilized to make a new muscle tissue given that you are into weight-training course. To increase your calorie higher than your to TDEE to obtain more weight is the next procedure. To obtain muscular bodyweight you must have a well-balanced calorie diet, which is the fundamental law of energy balance. An additional of roughly 300-500 calories a day on your TDEE is a common rule for an initial point for increasing weight. To include an extra 15 - 20% on your TDEE is another option you can do.

TDEE: 2033 calories
added calorie constraint for gaining weight: + 15 - 20% = 305 - 406 calories
best caloric ingestion for gaining weight: 2033 + 305 - 406 = 2338 - 2439 calories>

Regulate your caloric consumption slowly

If you are going to diet it is not good to change your overall diet drastically. If the amount of overall day-by-day energy outflow and the adjustment according to your objective is considerably lower or higher than your present consumption then you might be required to regulate your calories slowly. For instance, if found out that your best caloric consumption is 1900 calories a day, however you have just started consuming 900 calories a day, it might result to slow metabolism. If this is the case and you suddenly shift to 1900 calories a day this might result to fat gain due to the fact that your body has already been use to a lesser caloric consumption and the immediate creates an excess calorie. The best way to do it is to slowly increase your calories per day until such time that reaches the amount of 1900 calories to give way to your metabolism to increase and stabilize.

Calculate your outcome and regulate calories consequently
To provide you with a starting point the computation for searching the right caloric consumption are very simple and are merely approximation. You must give time to study your development to identify if this is the right level for you. To know that you are in the right level you should take note of your bodyweight, calorie consumption and body fat gain. How you respond depends on the result of your body fat percentage and bodyweight. You need to exercise levels consequently and regulate your caloric consumption if you do not notice the results expected. The important note is that it is not good to reduce calorie consumption in such a very low level in order to drop fat. As long as you are involved in physical activities and with a proper calorie deficit consuming more calorie is better. The best way is to slowly decrease calories in a little and increase your day-by-day calorie outflow by incrementing your regularity, time and or the concentration of the work out.

Bookmark and Share

6 Comment(s)

i really i dont understand what you talking about on this note. What is the calories,how is works in our body and how is form .
By: tenzin 10 years ago
I hear the Acai berries were only at their best eaten fresh, not processed. I agree the formula is good. It took me a while as I am not that adept at math :).
By: Deborah 10 years ago
Too much info to process. There must be an easier method and proof reading would help.
By: sherry 10 years ago
Too much info to process. There must be a simplerer method and proof reading would help.
By: sherry 10 years ago
By: CHRISTINE 11 years ago
excellent fully informative
By: dilip pitale 11 years ago

Write a comment