Nikiya Anton Bettey 2021

A 710-millilitre (24 US fl oz) energy drinkwith 330 kilocalories

The calorie is a unit of energy defined as the amount of heat needed to raise the temperature of a quantity of water by one degree.

For historical reasons, two main definitions of calorie are in wide use. The small calorie or gram calorie(usually denoted cal) is the amount of heat needed to raise the temperature of one gram of water by one degree Celsius (or one kelvin).^[1]^[2] The large calorie, food calorie, or kilocalorie (Cal, Calorie or kcal), most widely used in nutrition,^[3] is the amount of heat needed to cause the same increase in one kilogramof water.^[4] Thus, 1 kilocalorie (kcal) = 1000 calories (cal). By convention in food science, the large calorie is commonly called Calorie (with a capital C by some authors to distinguish from the smaller unit).^[5] In most countries, labels of industrialized food products are required to indicate the nutritional energy value in (kilo or large) calories per serving or per weight.

Calorie relates directly to the metric system, and therefore to the SI system. It has been regarded as obsolete within the scientific community since the adoption of the SI system, but is still in some use.^[3] The SI unit of energy is the joule. One calorie is defined as exactly 4.184 J, and one Calorie (kilocalorie) is 4184 J.

History[edit]

The calorie was first introduced by Nicolas Clément, as a unit of heat energy, in lectures during the years 1819–1824. This was the "large" calorie, viz. modern kilocalorie.^[3]^[6] The term entered French and English dictionaries between 1841 and 1867. It comes from Latin calor 'heat'.

The "small" calorie (modern calorie) was introduced by Pierre Antoine Favre (Chemist) and Johann T. Silbermann (Physicist) in 1852. In 1879, Marcellin Berthelot distinguished between gram-calorie (modern calorie) and kilogram-calorie (modern kilocalorie).^[6] Berthelot also introduced the convention of capitalizing the kilogram-calorie, as Calorie.

The use of the kilogram-calorie (kcal) for nutrition was introduced to the American public by Wilbur Olin Atwater, a professor at Wesleyan University, in 1887.^[3]

The modern calorie (cal) was first recognized as a unit of the cm-g-s system (cgs) in 1896,^[6] alongside the already-existing cgs unit of energy, the erg(first suggested by Clausius in 1864, under the name ergon, and officially adopted in 1882).

Already in 1928 there were serious complaints about the possible confusion arising from the two main definitions of the calorie and whether the notion of using the capital letter to distinguish them was sound.^[7] Use of the calorie was officially deprecated by the ninth General Conference on Weights and Measures, in 1948.^[8]

The alternate spelling calory is archaic.

Definitions[edit]

The modern (small) calorie is defined as the amount of energy needed to increase the temperature of 1 gram of water by 1 °C (or 1 K, which is the same increment).^[1]^[2] The definition depends on the atmospheric pressure and the starting temperature. Accordingly, several different precise definitions of the calorie have been used.

Name	Symbol	Conversions	Definition and notes
Thermochemicalcalorie	cal_th	≡ 4.184 J ≈ 0.003964 BTU≈ 1.162×10⁻⁶ kW⋅h≈ 2.611×10¹⁹ eV	The amount of energy equal to exactly 4.184 J (Joules) and 1 kJ = 0.239 kcal.^[9]^[10]^[11] (a).
4 °C calorie	cal₄	≈ 4.204 J ≈ 0.003985 BTU≈ 1.168×10⁻⁶ kW⋅h ≈ 2.624×10¹⁹ eV	The amount of energy required to warm one gram of air-free water from 3.5 to 4.5 °C at standard atmospheric pressure. (c)
15 °C calorie	cal₁₅	≈ 4.1855 J ≈ 0.0039671 BTU≈ 1.1626×10⁻⁶ kW⋅h ≈ 2.6124×10¹⁹ eV	The amount of energy required to warm one gram of air-free water from 14.5 to 15.5 °C at standard atmospheric pressure. (c) Experimental values of this calorie ranged from 4.1852 to 4.1858 J. The CIPM in 1950 published a mean experimental value of 4.1855 J, noting an uncertainty of 0.0005 J.^[9]
20 °C calorie	cal₂₀	≈ 4.182 J ≈ 0.003964 BTU≈ 1.162×10⁻⁶ kW⋅h ≈ 2.610×10¹⁹ eV	The amount of energy required to warm one gram of air-free water from 19.5 to 20.5 °C at standard atmospheric pressure. (c)
Mean calorie	cal_mean	≈ 4.190 J ≈ 0.003971 BTU≈ 1.164×10⁻⁶ kW⋅h ≈ 2.615×10¹⁹ eV	Defined as 1⁄100 of the amount of energy required to warm one gram of air-free water from 0 to 100 °C at standard atmospheric pressure. (c)
International Steam Tablecalorie (1929)		≈ 4.1868 J ≈ 0.0039683 BTU≈ 1.1630×10⁻⁶ kW⋅h ≈ 2.6132×10¹⁹ eV	Defined as 1⁄860 "international" watt hours = 180⁄43 "international" joules exactly. (b)
International Steam Table calorie (1956)	cal_IT	≡ 4.1868 J ≈ 0.0039683 BTU= 1.1630×10⁻⁶ kW⋅h ≈ 2.6132×10¹⁹ eV	Defined as 1.163 mW⋅h = 4.1868 J exactly. This definition was adopted by the Fifth International Conference on Properties of Steam (London, July 1956).^[9]

(a) The 'Thermochemical calorie' was defined by Rossini simply as 4.1833 international joules in order to avoid the difficulties associated with uncertainties about the heat capacity of water. It was later redefined as 4.1840 J exactly.^[12]

(b) The figure depends on the conversion factor between "international joules" and "absolute" (modern, SI) joules. Using the mean international ohm and volt (1.00049 Ω, 1.00034 V^[13]), the "international joule" is about 1.00019 J, using the US international ohm and volt (1.000495 Ω, 1.000330 V) it is about 1.000165 J, giving 4.18684 and 4.18674 J, respectively.

(c) The standard atmospheric pressure can be taken to be 101.325 kPa.

The two definitions most common in older literature appear to be the 15 °C calorie and the thermochemical calorie. Until 1948, the latter was defined as 4.1833 international joules; the current standard of 4.184 J was chosen to have the new thermochemical calorie represent the same quantity of energy as before.^[10]

The calorie was first defined specifically to measure energy in the form of heat, especially in experimental calorimetry.^[14]

Nutrition[edit]

In a nutritional context, the kilojoule (kJ) is the SI unit of food energy, although the calorie is commonly used.^[15]^[16] The word calorie is commonly used with the number of kilocalories (kcal) of nutritional energy measured.

In the United States, most nutritionists prefer the unit kilocalorie to the unit kilojoules, whereas most physiologists prefer to use kilojoules. In the majority of other countries, nutritionists prefer the kilojoule to the kilocalorie.^[17] US food labelling laws require the use of kilocalories (under the name of "Calories"); kilojoules are permitted to be included on food labels alongside kilocalories, but most food labels do not do so. In Australia, kilojoules are officially preferred over kilocalories, but kilocalories retain some degree of popular use.^[18] Australian and New Zealand food labelling laws require the use of kilojoules; kilocalories are allowed to be included on labels in addition to kilojoules, but are not required.^[19] EU food labelling laws require both kilojoules and kilocalories on all nutritional labels, with the kilojoules listed first.^[20]

To facilitate comparison, specific energy or energy density figures are often quoted as "calories per serving" or "kcal per 100 g". A nutritional requirement or consumption is often expressed in calories or kilocalories per day.

Food nutrients as fat (lipids) contains 9 kilocalories per gram (kcal/g), while carbohydrate (sugar) or protein contains approximately 4 kcal/g.^[21] Alcohol in food contains 7 kcal/g.^[22] Food nutrients are also often quoted "per 100 g".

Chemistry[edit]

In other scientific contexts, the term calorie almost always refers to the small calorie. Even though it is not an SI unit, it is still used in chemistry. For example, the energy released in a chemical reaction per mole of reagent is occasionally expressed in kilocalories per mole.^[23] Typically, this use was largely due to the ease with which it could be calculated in laboratory reactions, especially in aqueous solution: a volume of reagent dissolved in water forming a solution, with concentration expressed in moles per litre (1 litre weighing 1 kilogram), will induce a temperature change in degrees Celsius in the total volume of water solvent, and these quantities (volume, molar concentration and temperature change) can then be used to calculate energy per mole. It is also occasionally used to specify energy quantities that relate to reaction energy, such as enthalpy of formation and the size of activation barriers.^[24] However, its use is being superseded by the SI unit, the joule, and multiples thereof such as the kilojoule.

Measurement of energy content of food[edit]

In the past, a bomb calorimeter was used to determine the energy content of food by burning a sample and measuring a temperature change in the surrounding water. Today, this method is not commonly used in the United States and has been replaced by calculating the energy content indirectly from adding up the energy provided by energy-containing nutrients of food (such as protein, carbohydrates, and fats), the Modified Atwater system. The fibre content is also subtracted to account for the fact that fibre is not digested by the body.^[21]

Nutrition labels[edit]

The nutritional information label on a pack of Basmati rice in the United Kingdom

Many governments require food manufacturers to label the energy content of their products, to help consumers control their energy intake.^[6] In the European Union, manufacturers of packaged food must label the nutritional energy of their products in both kilocalories and kilojoules, when required. In the United States, the equivalent mandatory labels display only "Calories",^[7] often as a substitute for the name of the quantity being measured, food energy; an additional kilojoules figure is optional and is rarely used. In Australia and New Zealand, the food energy must be stated in kilojoules (and optionally in kilocalories as well), and other nutritional energy information is similarly conveyed in kilojoules.^[8]^[9] The energy available from the respiration of food is usually given on labels for 100 g, for a typical serving size (according to the manufacturer), and/or for the entire pack contents.^{[citation needed]}

The amount of food energy associated with a particular food could be measured by completely burning the dried food in a bomb calorimeter, a method known as direct calorimetry.^[10] However, the values given on food labels are not determined in this way. The reason for this is that direct calorimetry also burns the dietary fiber, and so does not allow for fecal losses; thus direct calorimetry would give systematic overestimates of the amount of fuel that actually enters the blood through digestion. What are used instead are standardized chemical tests or an analysis of the recipe using reference tables for common ingredients^[11] to estimate the product's digestible constituents (protein, carbohydrate, fat, etc.). These results are then converted into an equivalent energy value based on the following standardized table of energy densities.^[4]^[12] However "energy density" is a misleading term for it once again assumes that energy is IN the particular food, whereas it simply means that "high density" food needs more oxygen during respiration, leading to greater transfer of energy.^[1]^[13]

Note that the following standardized table of energy densities^[12] is an approximation and the value in kJ/g does not convert exactly to kcal/g using a conversion factor.

Food component	Energy density
Food component	kJ/g	kcal/g
Fat	37	9
Ethanol (drinking alcohol)	29	7
Proteins	17	4
Carbohydrates	17	4
Organic acids	13	3
Polyols (sugar alcohols, sweeteners)	10	2.4
Fiber	8	2

All the other nutrients in food are noncaloric and are thus not counted.

Recommended daily intake[edit]

Increased mental activity has been linked with moderately increased brain energy consumption.^[14] Older people and those with sedentary lifestylesrequire less energy; children and physically active people require more.

Recommendations in the United States are 10,900 and 8,400 kJ (2,600 and 2,000 kcal) for men and women (respectively) between 31 and 35, at a physical activity level equivalent to walking about 2.5 to 5 km (1+1⁄2 to 3 mi) per day at 5 to 6 km/h (3 to 4 mph) in addition to the light physical activity associated with typical day-to-day life,^[15] with French guidance suggesting roughly the same levels.^[16]

Recognizing that people of different age and gender groups have varying daily activity levels, Australia's National Health and Medical Research Councilrecommends no single daily energy intake, but instead prescribes an appropriate recommendation for each age and gender group.^[17] Notwithstanding, nutrition labels on Australian food products typically recommend the average daily energy intake of 8,800 kJ (2,100 kcal).

According to the Food and Agriculture Organization of the United Nations, the average minimum energy requirement per person per day is about 7,500 kJ (1,800 kcal).^[18]

List of countries by food energy intake[edit]

Energy usage in the human body[edit]

The human body uses the energy released by respiration for a wide range of purposes: about 20% of the energy is used for brain metabolism, and much of the rest is used for the basal metabolic requirements of other organs and tissues. In cold environments, metabolism may increase simply to produce heat to maintain body temperature. Among the diverse uses for energy, one is the production of mechanical energy by skeletal muscle to maintain posture and produce motion.

The conversion efficiency of energy from respiration into mechanical (physical) power depends on the type of food and on the type of physical energy usage (e.g., which muscles are used, whether the muscle is used aerobically or anaerobically). In general, the efficiency of muscles is rather low: only 18 to 26% of the energy available from respiration is converted into mechanical energy.^[19] This low efficiency is the result of about 40% efficiency of generating ATP from the respiration of food, losses in converting energy from ATP into mechanical work inside the muscle, and mechanical losses inside the body. The latter two losses are dependent on the type of exercise and the type of muscle fibers being used (fast-twitch or slow-twitch). However, alterations in the structure of the material consumed can cause modifications in the amount of energy that can be derived from the food; i.e. caloric value depends on the surface area and volume of a food. For an overall efficiency of 20%, one watt of mechanical power is equivalent to 18 kJ/h (4.3 kcal/h). For example, a manufacturer of rowing equipment shows calories released from "burning" food as four times the actual mechanical work, plus 1,300 kJ (300 kcal) per hour,^[20] which amounts to about 20% efficiency at 250 watts of mechanical output. It can take up to 20 hours of little physical output (e.g., walking) to "burn off" 17,000 kJ (4,000 kcal)^[21] more than a body would otherwise consume. For reference, each kilogram of body fat is roughly equivalent to 32,300 kilojoules of food energy (i.e., 3,500 kilocalories per pound).^[22]

In addition, the quality of calories matters because the energy absorption rate of different foods with equal amounts of calories may vary.^{[citation needed]}Some nutrients have regulatory roles affected by cell signaling, in addition to providing energy for the body.^[23] For example, leucine plays an important role in the regulation of protein metabolism and suppresses an individual's appetite.^[24]

Swings in body temperature – either hotter or cooler – increase the metabolic rate, thus burning more energy. Prolonged exposure to extremely warm or very cold environments increases the basal metabolic rate (BMR). People who live in these types of settings often have BMRs 5–20% higher than those in other climates.^{[citation needed]} Physical activity also significantly increases body temperature, which in turn uses more energy from respiration.^{[citation needed]}

Predicting the bond strength by radius[edit]

Metallic radius, ionic radius, and covalent radius of each atom in a molecule can be used to estimate the bond strength. For example, the covalentradius of boron is estimated at 83.0 pm, but the bond length of B–B in B₂Cl₄ is 175 pm, a significantly larger value. This would indicate that the bond between the two boron atoms is a rather weak single bond. In another example, the metallic radius of rhenium is 137.5 pm, with a Re–Re bond length of 224 pm in the compound Re₂Cl₈. From this data, we can conclude that the bond is a very strong bond or a quadruple bond. This method of determination is most useful for covalently bonded compounds.^[10]

Factors affecting ionic bond energy[edit]

The electronegativity of the two atoms bonding together affects ionic bond energy.^[11] The farther away the electronegativity of 2 atoms, the stronger the bond generally. For example, Cesium has the lowest, and Fluorine has the highest and the make the strongest ionic bond (well single bond at least). Assuming the strongest polar covalent is the Carbon-Fluorine bond. And mostly, ionic bonds are stronger than covalent bonds. By checking at melting points, ionic compounds have high melting points and covalent compounds have low melting points.^[12]

Watt-second[edit]

A watt-second (symbol W s or W·s) is a derived unit of energy equivalent to the joule.^[25] The watt-second is the energy equivalent to the power of one watt sustained for one second. While the watt-second is equivalent to the joule in both units and meaning, there are some contexts in which the term "watt-second" is used instead of "joule".^[why?]

Photography[edit]

In photography, the unit for flashes is the watt-second. A flash can be rated in watt-seconds (e.g., 300 W⋅s) or in joules (different names for the same thing), but historically, the term "watt-second" has been used and continues to be used.

{\text{Energy of a flash in joules or watt-seconds}}={\dfrac {1}{2}}\cdot {\text{capacitance of the storage capacitor in farads}}\cdot {\text{working voltage}}^{2}

The energy rating a flash is given is not a reliable benchmark for its light output because there are numerous factors that affect the energy conversion efficiency. For example, the construction of the tube will affect the efficiency, and the use of reflectors and filters will change the usable light output towards the subject. Some companies specify their products in "true" watt-seconds, and some specify their products in "nominal" watt-seconds.^[26]

Forms of energy[edit]

Chemical energy – energy contained in molecules
Electrical energy – energy from electric fields
Electro-centric energy – energy sustaining the continuous motion of free electrons.[1]
Gravitational energy – energy from gravitational fields
Ionization energy – energy that binds an electron to its atom or molecule
Kinetic energy – ( $\geq0$ ), energy of the motion of a body
Magnetic energy – energy from magnetic fields
Mechanical energy – The sum of (usually macroscopic) kinetic and potential energies
Mechanical wave – ( $\geq0$ ), a form of mechanical energy propagated by a material's oscillations
Nuclear binding energy – energy that binds nucleons to form the atomic nucleus
Potential energy – energy possessed by a body by virtue of its position relative to others, stresses within itself, electric charge, and other factors.^[3]^[4]
- Elastic energy – energy of deformation of a material (or its container) exhibiting a restorative force
- Gravitational energy – potential energy associated with a gravitational field.
- Nuclear potential energy
Radiant energy – ( $\geq0$ ), energy of electromagnetic radiation including light
Rest energy – ( $\geq0$ ) that E=mc² an object's rest mass
Surface energy
Thermal energy – a microscopic, disordered equivalent of mechanical energy
- Heat – an amount of thermal energy being transferred (in a given process) in the direction of decreasing temperature
Work (physics) – an amount of energy being energy transfer in a given Process (thermodynamic) due to displacement in the direction of an applied force

Measurement[edit]

Units[edit]

List of common units for energy. Official or common symbol in brackets after name and exact or approximate value of unit in joule in brackets after description.

SI unit[edit]

Joule (J) – the SI-unit for energy. Also called newton meter, watt second, or coulomb volt.

Other metric units[edit]

Kilowatt-hour (kW·h) – corresponds to one kilowatt of power being used over a period of one hour (3.6 MJ).
Calorie (cal) – equal to the energy need to raise the temperature of one gram of water by one degree Celsius (~4.184 J).
Erg (erg) – unit of energy and mechanical work in the centimetre-gram-second (CGS) system of units (10⁻⁷ J).

Imperial or US Customary units[edit]

British thermal unit (BTU) – equal to the energy need to raise the temperature of one pound of water by one degree Fahrenheit (~1055 J).
Therm (thm) – unit of heat energy. In the US gas industry it is defined as exactly 100,000 BTU_59 °F. It is approximately the heat equivalent of burning 100 cubic feet (2.8 m³) of natural gas (~105.5 MJ).
Quad – unit of energy equal to 10¹⁵ (a short-scale quadrillion) BTU.
Foot-pound (ft·lbf or ft·lbf) – unit of mechanical work, or energy, although in scientific fields one commonly uses joule (~1.356 J).

Other units[edit]

Electronvolt (eV) – the amount of energy gained by a single unbound electron when it falls through an electrostatic potential difference of one volt (~1.60 × 10⁻¹⁹ J).
Planck energy ( $E P$ ) – natural unit of energy common in particle physics (~1.96×10⁹ J).
Barrel of oil equivalent (BOE) – energy unit equal to the energy released when burning one barrel (159 litres) of oil (~6.12 GJ).
Tonne of oil equivalent (toe) – energy unit equal to the energy released when burning one tonne of oil (~42 GJ).

Related units and concepts[edit]

Volt
Ampere
Coulomb
Enthalpy
EU energy label
Fill factor – defined as the ratio of the maximum power (Vmp x Jmp) divided by the short-circuit current (Isc) and open-circuit voltage (Voc) in light current density – voltage (J-V) characteristics of solar cells.
Gigaton – Metric Unit of mass, equal to 1,000,000,000 (1 billion) metric tons, 1,000,000,000,000 (1 trillion) kilograms
- Any of various units of energy, such as gigatons of TNT equivalent, gigatons of coal equivalent, gigatons petroleum equivalent.
Gray (unit) – (symbol: Gy), is the SI unit of energy for the absorbed dose of radiation. One gray is the absorption of one joule of radiation energy by one kilogram of matter. One gray equals 100 rad, an older unit.
Heat
Mass-energy equivalence – where mass has an energy equivalence, and energy has a mass equivalence
Megawatt
Net energy gain
Power factor – of an AC electric power system is defined as the ratio of the real power to the apparent power.

Energy industry[edit]

Energy industry

Worldwide energy supply, outline by country/region
World energy resources and consumption
List of energy resources, substances like fuels, petroleum products and electricity
Energy crisis, the need to conserve energy resources
Energy development, development of energy resources — ongoing effort to provide abundant and accessible energy, through knowledge, skills and construction
Embodied energy, the sum total of energy expended to deliver a good or service as it travels through the economy
Energy conservation, tips for conserving energy resources
Energy economics, as the foundation of other relationships
Energy policy, government policies and plans for energy supply
Energy storage, methods commonly used to store energy resources for later use
Energy system, an interpretation the energy sector in system terms
Biosphere
Ecological energetics
Ecology
Energy balance
Earth Day
Energy speculation
Free energy suppression
Future energy development – Provides a general overview of future energy development.
History of perpetual motion machines
Hubbert peak theory, also known as peak oil – the theory that world oil production will peak (or has peaked), and will then rapidly decline, with a corresponding rapid increase in prices.
Primary production
Power harvesting
Renewable energy development

Energy infrastructure[edit]

See especially Category:Electric power and Category:Fuels for a large number of conventional energy related topics.

Energy applications[edit]

History of energy[edit]

History of energy

History of the energy industry

Physics of energy[edit]

Energy
Activation energy, explains the differences in the speeds of various chemical reactions
Bioenergetics
Chemical energetics
Energy in physical cosmology
Energy in Earth science that is responsible for the macroscopic transformations on the planet Earth
Electricity
Exergy
Green energy
Orders of magnitude (energy), list describing various energy levels between 10⁻³¹ joules and 10⁷⁰ joules
Thermodynamics
Perpetual motion
Heat
History of energy
Forms of energy, the forms in which energy can be defined
Energy transformation, relating to energy's changes from one form to another.
Energy (signal processing), the inner product of a signal in the time domain
Energy density spectrum, relating to the distribution of signal energy over frequencies.
Potential energy, the form of energy that is due to position of an object
Kinetic energy, the form of energy as a consequence of the motion of an object or its constituents
Mechanical energy, the potential energy and kinetic energy present in the components of a mechanical system
Binding energy, a concept explaining how the constituents of atoms or molecules are bound together
Bond energy, a measure of the strength of a chemical bond
Nuclear energy, energy that is the consequence of decomposition or combination of atomic nuclei
Osmotic power, also salinity gradient power or blue energy, the energy available from the difference in the salt concentration between seawater and river water
Gibbs free energy, a related concept in chemical thermodynamics that incorporates entropy considerations
Helmholtz free energy, a thermodynamic potential that measures the "useful" work obtainable from a closed thermodynamic system at a constant temperature, useful for studying explosive chemical reactions
Elastic energy, which causes or is released by the elastic distortion of a solid or a fluid
Ionization energy (IE), the energy required to strip an atom of an electron
Interaction energy, the contribution to the total energy that is a result of interaction between the objects being considered
Internal energy (abbreviated E or U), the total kinetic energy due to the motion of molecules (translational, rotational, vibrational) and the total potential energy associated with the vibrational and electric energy of atoms within molecules.
Negative energy
Energy conversion, process of converting energy from one form to another
Dark energy, used to explain some cosmological phenomena
Energy quality, empirical experience of the characteristics of different energy forms as they flow and transform
Energy density, amount of energy stored in a given system or region of space per unit volume, or per unit mass
Energy flow, flow of energy in an ecosystem through food chains
Energetics (disambiguation), the scientific study of energy in general
Stress–energy tensor, the density and flux of energy and momentum in space-time; the source of the gravitational field in general relativity
Food energy, energy in food that is available
Primary energy, energy contained in raw fuels and any other forms of energy received by a system as input to the system.
Radiant energy, energy that is transported by waves
Rotational energy, part of an object's total kinetic energy due to its rotation
Solar radiation, radiant energy emitted by the sun, particularly electromagnetic energy
Tidal power, also called tidal energy, is a form of hydropower that converts the energy of tides into useful forms of power - mainly electricity, dynamic tidal power, tidal lagoons, tidal barrages
Wave power is the transport of energy by ocean surface waves, and the capture of that energy to do useful work — for example, electricity generation, water desalination, or the pumping of water (into reservoirs). Machinery able to exploit wave power is generally known as a wave energy converter (WEC).
Wind energy is the kinetic energy of air in motion;Wind power is the conversion of wind energy into a useful form of energy, such as using wind turbines to make electricity, windmills for mechanical power, windpumps for water pumping or drainage, or sails to propel ships

Allegorical and esoteric[edit]

Energy (esotericism), invoked by spiritualists for alternative modes of healing the human body as well as a spirit that permeates all of reality.
Orgone, Wilhelm Reich discovered this energy and tried to use it to cure various physical ailments and control the weather.
Bioenergetic analysis, body-oriented Reichian psychotherapy
Qi, a concept from Oriental medicine that is sometimes translated as "energy" in the West.
Vitalism, often referred to as "energy"
Cold fusion, nuclear fusion at conditions close to room temperature.
Bubble fusion, also known as Sonofusion, energy from acoustic collapse of bubbles.
Water-fuelled car, powering a car using water as fuel.

Politics[edit]

Energy issues[edit]

2000 Watt society
Environmental concerns with electricity generation
Fuel poverty
Greasestock, American showcase of vehicles and technologies powered by alternative energy
Low-carbon economy
Decarbonisation plans that get to zero CO₂ emissions
Peak Oil
Soft energy path – an energy use and development strategy delineated and promoted by some energy experts and activists
Strategic Petroleum Reserve (disambiguation)

Energy policies and use – national and international[edit]

International[edit]

Energy policy – an introductory article
Energy and Environmental Security Initiative

Regional and national[edit]

Energy law – overview of many energy laws from various countries and states
- New York energy law
Energy Tax Act – United States energy-related legislation. See also : Category:United States federal energy legislation
United Kingdom:
- Energy policy of the United Kingdom
- Energy use and conservation in the United Kingdom

Economics[edit]

Energy economics

Energy companies[edit]

Exxon Mobil
Enercon GmbH – Company based in Germany that operates in the wind turbine industry. One of the biggest producers in the world.
Saudi Aramco
Sasol
United States Enrichment Corporation – contracts with the United States Department of Energy to produce enriched uranium.

Non-profit organizations[edit]

Musicians United for Safe Energy

Industry associations[edit]

OPEC – Organization of Petroleum-exporting Countries
IEA – International Energy Agency
CAPP – Canadian Association of Petroleum Producers
World LP Gas Association – WLPGA

Innovators[edit]

Alessandro Volta
Charles Kettering
Farrington Daniels – solar energy
Georges Leclanché – battery
John Frederic Daniell – Daniell cell
Rudolf Diesel – compression ignition internal combustion engine
Georges Imbert – wood gas
Leonardo da Vinci
Moritz von Jacobi
Nicolaus Otto – internal combustion engine
Robert Stirling – Stirling engine (external combustion)
Nikola Tesla
James Watt – steam engine with separate condensor

Lists[edit]

United States[edit]

Description[edit]

In the United States, the Nutritional Facts label lists the percentage supplied that is recommended to be met, or to be limited, in one day of human nutrients based on a daily diet of 2,000 calories.

With certain exceptions, such as babies foods, the following Daily Values are used.^[21] These are called Reference Daily Intake (RDI) values and were originally based on the highest 1968 Recommended Dietary Allowances (RDA) for each nutrient in order to assure that the needs of all age and sex combinations were met.^[22] These are older than the current Recommended Dietary Allowances of the Dietary Reference Intake. For vitamin C, vitamin D, vitamin E, vitamin K, calcium, phosphorus, magnesium, and manganese, the current highest RDAs are up to 50% higher than the older Daily Values used in labeling, whereas for other nutrients the recommended needs have gone down. A side-by-side table of the old and new adult Daily Values is provided at Reference Daily Intake. As of October 2010, the only micronutrients that are required to be included on all labels are vitamin A, vitamin C, calcium, and iron.^[23] To determine the nutrient levels in the foods, companies may develop or use databases, and these may be submitted voluntarily to the U.S. Food and Drug Administration for review.^[24]

Nutrient	Daily Value for label (before 2016 update)	highest RDA of DRI	unit
Vitamin A	5,000	3,000	IU
Vitamin C	60	90	mg
Thiamin	1.5	1.2	mg
Riboflavin	1.7	1.3	mg
Niacin	20	16	mg
Pantothenic acid	10	5	mg
Vitamin B6	2	1.7	mg
Folate	400	400	μg
Biotin	300	30	μg
Vitamin B12	6	2.4	μg
Vitamin D	400	600	IU
Vitamin E	12	15	mg
Vitamin K	80	120	μg
Calcium	1,000	1,300	mg
Iron	18	18	mg
Phosphorus	1,000	1,250	mg
Iodine	150	150	μg
Magnesium	400	420	mg
Zinc	15	11	mg
Selenium	70	55	μg
Copper	2	0.9	mg
Manganese	2	2.3	mg
Chromium	120	35	μg
Molybdenum	75	45	μg
Chloride	3,400	2,300	mg

Additionally, there is a requirement for ingredients to be listed in order from highest to lowest quantity, according to their weight.^[25] This requirement has some flexibility during the COVID-19 pandemic.^[26]^[27]

The original FDA Nutrition Facts label, as of 2006

The new Nutrition Facts label, in use since 2016.

The label was mandated for most food products under the provisions of the 1990 Nutrition Labeling and Education Act (NLEA), per the recommendations of the U.S. Food and Drug Administration.^[28] It was one of several controversial actions taken during the tenure of FDA Commissioner Dr. David Kessler. The law required food companies to begin using the new food label on packaged foods beginning May 8, 1994. (Meat and poultry products were not covered by NLEA, though the U.S. Department of Agriculture proposed similar regulations for voluntary labeling of raw meat and poultry.^[29]) Foods labeled before that day could use the old label. This appeared on all products in 1995. The old label was titled "Nutrition Information Per Serving" or simply, "Nutrition Information".

The label begins with a standard serving measurement, calories are listed second, and then following is a breakdown of the constituent elements including % daily value (%DV).^[30] Always listed are total fat, sodium, carbohydrates and protein; the other nutrients usually shown may be suppressed, if they are zero. Usually all 15 nutrients are shown: calories, calories from fat, fat, saturated fat, trans fat, cholesterol, sodium, carbohydrates, dietary fiber, sugars, protein, vitamin A, vitamin C, calcium, and iron.

Products containing less than 5 g of fat show amounts rounded to the nearest 0.5 g. Amounts less than 0.5 g are rounded to 0 g. For example, if a product contains 0.45 g of trans fat per serving, and the package contains 18 servings, the label would show 0 g of trans fat, even though the product actually contains a total of 8.1 g of trans fat.

In addition to the nutrition label, products may display certain nutrition information or health claims on packaging. These health claims are only allowed by the FDA for "eight diet and health relationships based on proven scientific evidence", including: calcium and osteoporosis, fiber-containing grain products, fruits and vegetables and cancer, fruits, vegetables, and grain products that contain fiber—particularly soluble fiber—and the risk of coronary heart disease, fat and cancer, saturated fat and cholesterol and coronary heart disease, sodium and hypertension, and folate and neural tube defects.^[31] The Institute of Medicine recommended these labels contain the most useful nutritional information for consumers: saturated fats, trans fats, sodium, calories, and serving size.^[32] In January 2011, food manufacturers and grocery stores announced plans to display some of this nutrition information on processed food.^[33]

The nutrition facts label currently appears on more than 6.5 billion food packages. President Bill Clinton issued an award of design excellence for the nutrition facts label in 1997 to Burkey Belser in Washington, DC.^[34]

The FDA does not require any specific typeface be used in the Nutrition Facts label, mandating only that the label "utilize a single easy-to-read type style",^[35] though its example label uses Helvetica.^[36] However, as regulated by the FDA and the USDA, it is mandatory for certain information listed in the label to be written in English, including: name of the product, net quantity, serving size and number of servings per package, nutrition facts, ingredient list, and name of manufacturer or distributor.^[37] The smallest lettering should be at least 1/16th of an inch tall (1.5875 millimeters), based on the height of a lowercase "o".^[38]

In January 2006, Trans fat was required to be listed under saturated fat. This was the first significant change to the Nutrition Facts panel since it was introduced in 1993.^[39]

2016 revision[edit]

In 2014, the U.S. Food and Drug Administration proposed several simultaneous improvements to nutrition labeling for the first time in over 20 years.^[40]^[41] The proposed changes were based on trends of consumption of nutrients of public health importance.^[42] However, studies had shown that the majority of the U.S. population could not understand the information in the then current Nutrition Facts Label.^[43] Nutrition label numeracy is particularly low in older individuals, of black and Hispanic race/ethnicity, who are unemployed, born outside of the US, have lower English proficiency, lower education achievement, lower income, or live in the South.^[44]

Final changes included raising serving sizes to more accurately reflect how many servings the average individual is actually consuming, removing "calories from fat" and instead focusing on total calories and type of fats being consumed in a product, and listing extra sugar added to a product, as well as declaring the amount of Vitamin D and potassium in a product and adjusting recommended Daily Value amounts.^[40]^[45]^[42] Some of these changes sparked a major debate between the food industry and public health agencies. The proposal to indicate sugar added during food production, in particular, was brought forward by the FDA as a measure to counter the increase in per capita sugar consumption in the US, which over the last decades exceeded the limits recommended by scientific institutions and governmental agencies.^[46]^[47] Major American food associations opposed the label change, indicating "lack of merit" and "no preponderance of evidence" to justify the inclusion of sugar added in the new label.^[48]^[49]

The rules for the new design were finalized on May 20, 2016. Manufacturers were initially given until July 26, 2018 to comply (or July 26, 2019 if they have less than $10 million in annual food sales);^[50] a rule change extend the compliance deadline to January 1, 2020 (or January 1, 2021 for smaller sellers).^[51]^[42] For food and dietary supplement labeling purposes the amounts of vitamins and nutritionally essential minerals in a serving are expressed as a percent of Daily Value (%DV). Many of the definitions of 100% Daily Value were changed as part of the revision.^[52] A table of the old and new adult Daily Values is provided at Reference Daily Intake.

Derivation[edit]

Available energy (as used by Atwater) is equivalent to the modern usage of the term metabolisable energy (ME).

{\text{Metabolisable Energy}}=\left({\text{Gross Energy in Food}}\right)-\left({\text{Energy lost in Faeces, Urine, Secretions and Gases}}\right).

In most studies on humans, losses in secretions and gases are ignored. The gross energy (GE) of a food, as measured by bomb calorimetry is equal to the sum of the heats of combustion of the components – protein (GE_p), fat (GE_f) and carbohydrate (GE_cho) (by difference) in the proximate system.

{GE}={{GE}_{p}+{GE}_{f}+{GE}_{cho}}\,

Atwater considered the energy value of feces in the same way.

{GE}^{F}={{GE}_{p}^{F}+{GE}_{f}^{F}+{GE}_{cho}^{F}}\,

By measuring coefficients of availability or in modern terminology apparent digestibility, Atwater derived a system for calculating faecal energy losses.

{\text{Digestible energy}}={{GE}_{p}(D_{p})}+{{GE}_{f}(D_{f})}+{{GE}_{cho}(D_{cho})}\,

where D_p, D_f, and D_cho are respectively the digestibility coefficients of protein, fat and carbohydrate calculated as

{\frac {{\text{intake}}-{\text{faecal excretion}}}{\text{intake}}}

for the constituent in question.

Urinary losses were calculated from the energy to nitrogen ratio in urine. Experimentally this was 7.9 kcal/g (33 kJ/g) urinary nitrogen and thus his equation for metabolisable energy became

{ME}=\left({GE}_{p}-{\frac {7.9}{6.25}}\right)D_{p}+{GE}_{f}D_{f}+{GE}_{cho}D_{cho}\,

Gross energy values[edit]

Atwater collected values from the literature and also measured the heat of combustion of proteins, fats and carbohydrates. These vary slightly depending on sources and Atwater derived weighted values for the gross heat of combustion of the protein, fat and carbohydrate in the typical mixed diet of his time. It has been argued that these weighted values are invalid for individual foods and for diets whose composition in terms of foodstuffs is different from those eaten in the US in the early 20th century.

Apparent digestibility coefficients[edit]

Atwater measured a large number of digestibility coefficients for simple mixtures, and in substitution experiments derived values for individual foods. These he combined in a weighted fashion to derive values for mixed diets. When these were tested experimentally with mixed diets they did not give a good prediction, and Atwater adjusted the coefficients for mixed diets.

Urinary correction[edit]

The energy/nitrogen ratio in urine shows considerable variation and the energy/organic matter is less variable, but the energy/nitrogen value provided Atwater with a workable approach although this has caused some confusion and only applies for subjects in nitrogen balance.

Energy or nutrient	Reference Intake
Energy	8400 kJ / 2000 kcal
Total fat	70 g
Saturates	20 g
Carbohydrates	260 g
Sugars	90 g
Protein	50 g
Salt	6 g

Age	Equation (kJ/day)	SEE
< 3	249 × W - 127	292
3–10	95 × W + 2110	280
10–18	74 × W + 2754	441
18–30	63 × W + 2896	641
30–60	48 × W + 3653	700
> 60	49 × W + 2459	686

Age	Equation (kJ/day)	SEE
< 3	244 × W - 130	246
3–10	85 × W + 2033	292
10–18	56 × W + 2898	466
18–30	62 × W + 2036	497
30–60	34 × W + 3538	465
> 60	38 × W + 2755	451

Age	Equation (kcal/day)	SEE
< 3	59.512 × W - 30.4	70
3–10	22.706 × W + 504.3	67
10–18	17.686 × W + 658.2	105
18–30	15.057 × W + 692.2	153
30–60	11.472 × W + 873.1	167
> 60	11.711 × W + 587.7	164

Age	Equation (kcal/day)	SEE
< 3	58.317 × W - 31.1	59
3–10	20.315 × W + 485.9	70
10–18	13.384 × W + 692.6	111
18–30	14.818 × W + 486.6	119
30–60	8.126 × W + 845.6	111
> 60	9.082 × W + 658.5	108

Blog Archive

Tuesday, September 28, 2021

09-27-2021-2138 - Dietary Reference Intake (DRI), Recommended Dietary Allowances (RDA), Reference Intakes (RI), Guideline Daily Amount (GDA), Body mass index (BMI), Schofield Equation, Basal metabolic rate (BMR), Thermodynamics, Bomb Calorimeter, Calorie, kcal, Joule, heat, energy, etc..

Parameters[edit]

External links[edit]

Bomb calorimeters[edit]

Combustion of non-flammables[edit]

History[edit]

Definitions[edit]

Nutrition[edit]

Chemistry[edit]

Measurement of energy content of food[edit]

See also[edit]

Nutrition labels[edit]

Recommended daily intake[edit]

List of countries by food energy intake[edit]

Energy usage in the human body[edit]

See also[edit]

Predicting the bond strength by radius[edit]

Factors affecting ionic bond energy[edit]

See also[edit]

Watt-second[edit]

Photography[edit]

See also[edit]

Forms of energy[edit]

Measurement[edit]

Units[edit]

SI unit[edit]

Other metric units[edit]

Imperial or US Customary units[edit]

Other units[edit]

Related units and concepts[edit]

Energy industry[edit]

Energy infrastructure[edit]

Energy applications[edit]

History of energy[edit]

Physics of energy[edit]

Allegorical and esoteric[edit]

Politics[edit]

Energy issues[edit]

Energy policies and use – national and international[edit]

International[edit]

Regional and national[edit]

Economics[edit]

Energy companies[edit]

Non-profit organizations[edit]

Industry associations[edit]

Innovators[edit]

Lists[edit]

See also[edit]

United States[edit]

Description[edit]

2016 revision[edit]

See also[edit]

Derivation[edit]

Gross energy values[edit]

Apparent digestibility coefficients[edit]

Urinary correction[edit]

See also[edit]

No comments:

Post a Comment