Editing Basal metabolic rate (section)

===BMR estimation formulas===
Several equations to predict the number of calories required by humans have been published from the early 20th–21st centuries. In each of the formulas below:<ref name="Harris1918"/>
: '''P''' is total heat production at complete rest,
: '''m''' is mass (kg),
: '''h''' is height (cm),
: '''a''' is age (years).

;The original Harris–Benedict equation
Historically, the most notable formula was the [[Harris–Benedict equation]], which was published in 1919:<ref name="Harris1918">{{cite journal |vauthors=Harris J, Benedict F |year=1918 |title=A Biometric Study of Human Basal Metabolism |journal=[[PNAS]] |volume=4 |issue=12 |pages=370–373 |bibcode=1918PNAS....4..370H |doi=10.1073/pnas.4.12.370 |pmc=1091498 |pmid=16576330|doi-access=free }}</ref>
: for men, <math>P = \left( \frac{13.7516 m}{1~\text{kg}} + \frac{5.0033 h}{1~\text{cm}} - \frac{6.7550 a}{1~\text{year}} + 66.4730 \right) \frac{\text{kcal}}{\text{day}},</math>
: for women, <math>P = \left( \frac{9.5634 m}{1~\text{kg}} + \frac{1.8496 h}{1~\text{cm}} - \frac{4.6756 a}{1~\text{year}} + 655.0955 \right) \frac{\text{kcal}}{\text{day}}.</math>

The difference in BMR for men and women is mainly due to differences in body mass. For example, a 55-year-old woman weighing {{convert|130|lb|kg}} and {{convert|66|in|cm|0}} tall would have a BMR of {{convert|1272|kcal|kJ}} per day.

;The revised Harris–Benedict equation
In 1984, the original Harris–Benedict equations were revised<ref>{{cite journal |vauthors=Roza AM, Shizgal HM |year=1984 |title=The Harris Benedict equation reevaluated: resting energy requirements and the body cell mass |url=http://www.balanseradstyrka.se/wp-content/uploads/2015/04/The-Harris-Benedict-equation-reevaluated-resting-energy-requirements-and-the-body-cell-mass..pdf |journal=[[The American Journal of Clinical Nutrition]] |volume=40 |issue=1 |pages=168–182 |pmid=6741850 |doi=10.1093/ajcn/40.1.168}}</ref> using new data. In comparisons with actual expenditure, the revised equations were found to be more accurate:<ref>{{cite journal |vauthors=Müller B, Merk S, Bürgi U, Diem P |year=2001 |title=Calculating the basal metabolic rate and severe and morbid obesity |journal=[[Praxis Journal of Philosophy|Praxis]] |volume=90 |issue=45 |pages=1955–63 |pmid=11817239}}</ref>
: for men, <math>P = \left( \frac{13.397 m}{1~\text{kg}} + \frac{4.799 h}{1~\text{cm}} - \frac{5.677 a}{1~\text{year}} + 88.362 \right) \frac{\text{kcal}}{\text{day}},</math>
: for women, <math>P = \left( \frac{9.247 m}{1~\text{kg}} + \frac{3.098 h}{1~\text{cm}} - \frac{4.330 a}{1~\text{year}} + 447.593 \right) \frac{\text{kcal}}{\text{day}}.</math>
It was the best prediction equation until 1990, when Mifflin ''et al.''<ref>{{cite journal |vauthors=Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA, Koh YO |year=1990 |title=A new predictive equation for resting energy expenditure in healthy individuals |journal=[[The American Journal of Clinical Nutrition]] |volume=51 |issue=2 |pages=241–247 |pmid=2305711|doi=10.1093/ajcn/51.2.241 }}</ref> introduced the equation:

;The Mifflin St Jeor equation
: <math>P = \left( \frac{10.0 m}{1~\text{kg}} + \frac{6.25 h}{1~\text{cm}} - \frac{5.0 a}{1~\text{year}} + s \right) \frac{\text{kcal}}{\text{day}},</math>
where ''s'' is +5 for males and −161 for females.

According to this formula, the woman in the example above has a BMR of {{convert|1204|kcal|kJ}} per day.
During the last 100&nbsp;years, lifestyles have changed, and Frankenfield ''et al.''<ref>{{cite journal |vauthors=Frankenfield D, Roth-Yousey L, Compher C |year=2005 |title=Comparison of predictive equations for resting metabolic rate in healthy, nonobese and obese adults: A systematic review |journal=[[Journal of the American Dietetic Association]] |volume=105 |issue=5 |pages=775–789 |doi=10.1016/j.jada.2005.02.005 |pmid=15883556}}</ref> showed it to be about 5% more accurate.

These formulas are based on body mass, which does not take into account the difference in metabolic activity between [[lean body mass]] and body fat. Other formulas exist which take into account lean body mass, two of which are the Katch–McArdle formula and Cunningham formula.

;The Katch–McArdle formula (resting daily energy expenditure)
The Katch–McArdle formula is used to predict resting daily energy expenditure (RDEE).<ref>{{cite book |last=McArdle |first=William |year=2006 |title=Essentials of exercise physiology |edition= 3rd |page=266 |publisher=Lippincott Williams & Wilkins |isbn=978-0-7817-4991-6}}</ref>
The Cunningham formula is commonly cited to predict RMR instead of BMR; however, the formulas provided by Katch–McArdle and Cunningham are the same.<ref>{{cite book |last1=Dunford |first1=Marie |last2=Doyle |first2=J. Andrew |year=2007 |title=Nutrition for Sport and Exercise |page=57 |publisher=Brooks/Cole |isbn=978-0-495-01483-6}}</ref>
: <math> P = 370 + 21.6 \cdot \ell,</math>
where '''''ℓ''''' is the lean body mass (''LBM'' in kg):
: <math> \ell = m \left( 1 - \frac{f}{100} \right),</math>
where '''''f''''' is the [[body fat percentage]].

According to this formula, if the woman in the example has a [[body fat percentage]] of 30%, her resting daily energy expenditure (the authors use the term of basal and resting metabolism interchangeably) would be 1262&nbsp;kcal per day.