Harris-Benedict equation
Encyclopedia
The Harris-Benedict equation (also called the Harris-Benedict principle) is a method used to estimate the daily calorie
requirements of an individual using their basal metabolic rate
or BMR. The estimated value is then multiplied by a number that corresponds to the person's activity level. The resulting number is the recommended daily calorie intake to maintain current weight
. The equation does not take into account calories burned by existing large amounts of muscle mass, nor does it account for the additional calories provided by excess body fat—so the equation is more effective for individuals at an ideal body weight or close to it.
The Harris-Benedict equation may be used to assist weight loss — by reducing the calorie intake to a number below the outcome of the equation.
Using the Harris-Benedict Equation, individuals can take a mathematical approach to weight loss. There are 3500 calories in 1 lb (0.45 kg) of body fat. Using the Harris-Benedict Principle, if someone has a daily allowance of 2500 calories, but he reduces his intake to 2000, then the calculations show a 1 pound loss every 7 days.
and Francis Gano Benedict
, which was published in 1919 by the Carnegie Institution of Washington
in the monograph
“A Biometric Study Of Basal Metabolism In Man”.
Calorie
The calorie is a pre-SI metric unit of energy. It was first defined by Nicolas Clément in 1824 as a unit of heat, entering French and English dictionaries between 1841 and 1867. In most fields its use is archaic, having been replaced by the SI unit of energy, the joule...
requirements of an individual using their basal metabolic rate
Basal metabolic rate
Basal Metabolic Rate , and the closely related resting metabolic rate , is the amount of daily energy expended by humans and other animals at rest. Rest is defined as existing in a neutrally temperate environment while in the post-absorptive state...
or BMR. The estimated value is then multiplied by a number that corresponds to the person's activity level. The resulting number is the recommended daily calorie intake to maintain current weight
Body weight
The term body weight is used in daily English speech as well as in the contexts of biological and medical sciences to describe the mass of an organism's body. Body weight is measured in kilograms throughout the world, although in some countries it is still measured in pounds or stones and pounds...
. The equation does not take into account calories burned by existing large amounts of muscle mass, nor does it account for the additional calories provided by excess body fat—so the equation is more effective for individuals at an ideal body weight or close to it.
The Harris-Benedict equation may be used to assist weight loss — by reducing the calorie intake to a number below the outcome of the equation.
Step 1- calculating the BMR
The following table enables calculation of an individuals Basal Metabolic Rate (BMR).| BMR calculation for men | BMR = 66.5 + ( 13.75 x weight in kg ) + ( 5.003 x height in cm ) – ( 6.775 x age in years ) |
| BMR calculation for men | BMR = 66 + ( 6.23 x weight in pounds ) + ( 12.7 x height in inches ) – ( 6.76 x age in years ) |
| BMR calculation for women | BMR = 655.1 + ( 9.563 x weight in kg ) + ( 1.850 x height in cm ) – ( 4.676 x age in years ) |
| BMR calculation for women | BMR = 655 + ( 4.35 x weight in pounds ) + ( 4.7 x height in inches ) – ( 4.7 x age in years ) |
Step 2 – applying the Harris-Benedict Principle
The following table enables calculation of an individuals recommended daily calorie intake to maintain current weight:| Little to no exercise | Daily calories needed = BMR x 1.2 |
| Light exercise (1–3 days per week) | Daily calories needed = BMR x 1.375 |
| Moderate exercise (3–5 days per week) | Daily calories needed = BMR x 1.55 |
| Heavy exercise (6–7 days per week) | Daily calories needed = BMR x 1.725 |
| Very heavy exercise (twice per day, extra heavy workouts) | Daily calories needed = BMR x 1.9 |
Applications for weight loss
Using the formulae above, a 24-year-old, 80 kg male who is 180 cm would have a BMR of 1900. If he exercised moderately, he would multiply his BMR by his activity level (1900 x 1.55) to determine daily calorie requirements, which would be 2945 kcal per day to keep his weight at 80 kg. This may seem like a high calorie intake, but his activity level requires it. This individual would exercise normally but not lose weight. The same individual without the exercise routine would only be able to consume 2273 kcal per day without gaining weight. The US Department of Health and Human Services Daily Value Guidelines provides figures that support the above example.Using the Harris-Benedict Equation, individuals can take a mathematical approach to weight loss. There are 3500 calories in 1 lb (0.45 kg) of body fat. Using the Harris-Benedict Principle, if someone has a daily allowance of 2500 calories, but he reduces his intake to 2000, then the calculations show a 1 pound loss every 7 days.
History
The Harris-Benedict equation sprang from a study by James Arthur HarrisJames Arthur Harris
James Arthur Harris was a botanist and biometrician, known for the Benedict-Harris equations,He was the Head of the Department of Botany at the University of Minnesota from 1924 to 1930....
and Francis Gano Benedict
Francis Gano Benedict
Francis Gano Benedict was an American nutritionist who developed a calorimeter and a spirometer used to determine oxygen consumption and measure metabolic rate....
, which was published in 1919 by the Carnegie Institution of Washington
Carnegie Institution for Science
The Carnegie Institution for Science is an organization in the United States established to support scientific research....
in the monograph
Monograph
A monograph is a work of writing upon a single subject, usually by a single author.It is often a scholarly essay or learned treatise, and may be released in the manner of a book or journal article. It is by definition a single document that forms a complete text in itself...
“A Biometric Study Of Basal Metabolism In Man”.
See also
- Food energyFood energyFood energy is the amount of energy obtained from food that is available through cellular respiration.Food energy is expressed in food calories or kilojoules...
- James Arthur HarrisJames Arthur HarrisJames Arthur Harris was a botanist and biometrician, known for the Benedict-Harris equations,He was the Head of the Department of Botany at the University of Minnesota from 1924 to 1930....
- Basal metabolic rateBasal metabolic rateBasal Metabolic Rate , and the closely related resting metabolic rate , is the amount of daily energy expended by humans and other animals at rest. Rest is defined as existing in a neutrally temperate environment while in the post-absorptive state...
- Resting metabolic rate