05-14-2023-1508 - BMR estimation formulas, body mass, scale, weight, Research on individual differences in BMR, experimental error, other factors, etc. (draft)

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:^[19]

P is total heat production at complete rest,

m is mass (kg),

h is height (cm),

a is age (years).

https://en.wikipedia.org/wiki/Basal_metabolic_rate#BMR_estimation_formulas

The Mifflin St Jeor equation

${\displaystyle P=\left(\frac{10.0m}{1\text{kg}}+\frac{6.25h}{1\text{cm}}-\frac{5.0a}{1\text{year}}+s\right)\frac{\text{kcal}}{\text{day}},}$

where s is +5 for males and −161 for females.

According to this formula, the woman in the example above has a BMR of 1,204 kilocalories (5,040 kJ) per day. During the last 100 years, lifestyles have changed, and Frankenfield et al.^[23] 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.

https://en.wikipedia.org/wiki/Basal_metabolic_rate#BMR_estimation_formulas

Research on individual differences in BMR

The basic metabolic rate varies between individuals. One study of 150 adults representative of the population in Scotland reported basal metabolic rates from as low as 1,027 kilocalories (4,300 kJ) per day to as high as 2,499 kilocalories (10,460 kJ); with a mean BMR of 1,500 kilocalories (6,300 kJ) per day. Statistically, the researchers calculated that 62% of this variation was explained by differences in fat free mass. Other factors explaining the variation included fat mass (7%), age (2%), and experimental error including within-subject difference (2%). The rest of the variation (27%) was unexplained. This remaining difference was not explained by sex nor by differing tissue size of highly energetic organs such as the brain.^[26]

A cross-sectional study of more than 1400 subjects in Europe and the US showed that once adjusted for differences in body composition (lean and fat mass) and age, BMR has fallen over the past 35 years.^[27] The decline was also observed in a meta-analysis of more than 150 studies dating back to the early 1920s, translating into a decline in total energy expenditure of about 6%.^[27] 

https://en.wikipedia.org/wiki/Basal_metabolic_rate#BMR_estimation_formulas

https://en.wikipedia.org/wiki/Mass_versus_weight

https://en.wikipedia.org/wiki/Metabolic_age

https://en.wikipedia.org/wiki/Category:Temporal_rates

https://en.wikipedia.org/wiki/Thermal_neutral_zone

https://en.wikipedia.org/wiki/Bradymetabolism

https://en.wikipedia.org/wiki/Indirect_calorimetry

https://en.wikipedia.org/wiki/Resting_metabolic_rate

 

https://en.wikipedia.org/wiki/Yellow-rumped_warbler

https://en.wikipedia.org/wiki/Schofield_equation

https://en.wikipedia.org/wiki/Respiration

 

https://en.wikipedia.org/wiki/Catabolism

 

https://en.wikipedia.org/wiki/Field_metabolic_rate

The pound or pound-mass is a unit of mass used in British imperial and United States customary systems of measurement. Various definitions have been used; the most common today is the international avoirdupois pound, which is legally defined as exactly 0.45359237 kilograms, and which is divided into 16 avoirdupois ounces.^[1] The international standard symbol for the avoirdupois pound is lb;^[2] an alternative symbol is lb_m^[3] (for most pound definitions), # (chiefly in the U.S.),^[4] and ℔^[5] or ″̶^[6] (specifically for the apothecaries' pound).

The unit is descended from the Roman libra (hence the abbreviation "lb"). The English word pound is cognate with, among others, German Pfund, Dutch pond, and Swedish pund. These units are historic and are no longer used (replaced by the metric system).

Usage of the unqualified term pound reflects the historical conflation of mass and weight. This accounts for the modern distinguishing terms pound-mass and pound-force. 

https://en.wikipedia.org/wiki/Pound_(mass)

 

https://en.wikipedia.org/wiki/Pound_(mass)

https://en.wikipedia.org/wiki/Weights_and_Measures_Acts_(UK)#Weights_and_Measures_Act_1878

https://en.wikipedia.org/wiki/Weights_and_Measures_Acts_(UK)#Weights_and_Measures_Act_1963

https://en.wikipedia.org/wiki/Traditional_French_units_of_measurement#Mass

https://en.wikipedia.org/wiki/European_units_of_measurement_directives

https://en.wikipedia.org/wiki/French_units_of_measurement

https://en.wikipedia.org/wiki/Russian_units_of_measurement

 

Conversion of units is the conversion between different units of measurement for the same quantity, typically through multiplicative conversion factors which change the measured quantity value without changing its effects.  

https://en.wikipedia.org/wiki/Conversion_of_units

https://en.wikipedia.org/wiki/Specification_(technical_standard)

https://en.wikipedia.org/wiki/Datasheet

https://en.wikipedia.org/wiki/Technical_standard

https://en.wikipedia.org/wiki/Standard_operating_procedure

https://en.wikipedia.org/wiki/Test_method

https://en.wikipedia.org/wiki/Measuring_instrument

https://en.wikipedia.org/wiki/Instrument_error

https://en.wikipedia.org/wiki/Error

https://en.wikipedia.org/wiki/Measuring_instrument

https://en.wikipedia.org/wiki/Clock

https://en.wikipedia.org/wiki/Atomic_clock

https://en.wikipedia.org/wiki/Sundial

https://en.wikipedia.org/wiki/Environment

A thermodynamic system is a body of matter and/or radiation, considered as separate from its surroundings, and studied using the laws of thermodynamics. Thermodynamic systems may be isolated, closed, or open. An isolated system exchanges no matter or energy with its surroundings, whereas a closed system does not exchange matter but may exchange heat and experience and exert forces. An open system can interact with its surroundings by exchanging both matter and energy. The physical condition of a thermodynamic system at a given time is described by its state, which can be specified by the values of a set of thermodynamic state variables. A thermodynamic system is in thermodynamic equilibrium when there are no macroscopically apparent flows of matter or energy within it or between it and other systems.^[1]

^{https://en.wikipedia.org/wiki/Thermodynamic_system}

^{https://en.wikipedia.org/wiki/Matter}

^{https://en.wikipedia.org/wiki/Radiation}

^{https://en.wikipedia.org/wiki/Thermodynamics}

 

^{https://en.wikipedia.org/wiki/Work_(thermodynamics)#Nearly_reversible_transfer_of_energy_by_work_in_the_surroundings}

 

^{https://en.wikipedia.org/wiki/Spontaneous_process}

^{https://en.wikipedia.org/wiki/Closed_system}

^{https://en.wikipedia.org/wiki/First_law_of_thermodynamics#Process_of_transfer_of_matter_between_an_open_system_and_its_surroundings}

^{https://en.wikipedia.org/wiki/Isothermal_process}

 

^{https://en.wikipedia.org/wiki/House_(astrology)}

 

^{https://en.wikipedia.org/wiki/Isolated_system}

 

Gas meter

A gas meter measures energy indirectly by recording the volume of gas used. This figure can then be converted to a measure of energy by multiplying it by the calorific value of the gas. 

https://en.wikipedia.org/wiki/Measuring_instrument

Action

Main article: Action (physics)

Action describes energy summed up over the time a process lasts (time integral over energy). Its dimension is the same as that of an angular momentum.

• A phototube provides a voltage measurement which permits the calculation of the quantized action (Planck constant) of light. (See also Photoelectric effect.)

https://en.wikipedia.org/wiki/Measuring_instrument

https://en.wikipedia.org/wiki/Category:Dimensional_instruments

https://en.wikipedia.org/wiki/Measuring_instrument

https://en.wikipedia.org/wiki/Category:Geometric_measuring_instruments

https://en.wikipedia.org/wiki/Orders_of_magnitude_(volume)

https://en.wikipedia.org/wiki/Energy

https://en.wikipedia.org/wiki/Conservation_law

 

https://en.wikipedia.org/wiki/Symmetry_(physics)

 

https://en.wikipedia.org/wiki/Technical_standard

https://en.wikipedia.org/wiki/Unit_of_measurement

https://en.wikipedia.org/wiki/Intellectual_property

https://en.wikipedia.org/wiki/Trade_secret

https://en.wikipedia.org/wiki/International_standard

https://en.wikipedia.org/wiki/International_standard

https://en.wikipedia.org/wiki/Specification_(technical_standard)

https://en.wikipedia.org/wiki/Conversion_of_units