Editing Nutrient (section)

=== Macronutrients ===
Macronutrients are defined in several ways.<ref name="Kern2005">{{cite book| first = Mark | last = Kern | name-list-style = vanc |title=CRC desk reference on sports nutrition|url=https://archive.org/details/crcdeskreference0000kern|url-access=registration|access-date=12 October 2010|date=12 May 2005|publisher=CRC Press|isbn=978-0-8493-2273-0|pages=[https://archive.org/details/crcdeskreference0000kern/page/117 117]–}}</ref>
* The [[chemical element]]s humans consume in the largest quantities are [[carbon]], [[hydrogen]], [[nitrogen]], [[oxygen]], [[phosphorus]], and [[sulphur]], summarized as [[CHNOPS]].
* The chemical compounds that humans consume in the largest quantities and provide bulk energy are classified as [[carbohydrate]]s, [[protein]]s, and [[fat]]s. Water must be also consumed in large quantities but does not provide caloric value.
* [[Calcium]], [[sodium]], [[potassium]], [[magnesium]], and [[chloride]] ions, along with phosphorus and sulfur, are listed with [[list of macronutrients|macronutrients]] because they are required in large quantities compared to [[micronutrient]]s, i.e., vitamins and other minerals, the latter often described as trace or ultratrace minerals.<ref>{{Cite web|date=2018-07-16|title=31.1C: Essential Nutrients for Plants|url=https://bio.libretexts.org/Bookshelves/Introductory_and_General_Biology/Book%3A_General_Biology_(Boundless)/31%3A_Soil_and_Plant_Nutrition/31.1%3A_Nutritional_Requirements_of_Plants/31.1C%3A_Essential_Nutrients_for_Plants|access-date=2020-08-16|website=Biology LibreTexts|language=en}}</ref>

Macronutrients provide energy:
* [[Carbohydrate]]s are compounds made up of types of [[sugar]]. Carbohydrates are classified according to their number of sugar units: [[monosaccharide]]s (such as [[glucose]] and [[fructose]]), [[disaccharide]]s (such as [[sucrose]] and [[lactose]]), [[oligosaccharide]]s, and [[polysaccharide]]s (such as [[starch]], [[glycogen]], and [[cellulose]]).
* [[Protein]]s are [[organic compound]]s that consist of [[amino acid]]s joined by [[peptide bond]]s. Since the body cannot manufacture some of the amino acids (termed [[essential amino acid]]s), the diet must supply them. Through digestion, [[protein]]s are [[protein catabolism|broken down]] by [[protease]]s back into free amino acids.
* [[Fat]]s consist of a [[glycerin]] molecule with three [[fatty acid]]s attached. Fatty acid molecules contain a -COOH group attached to unbranched [[hydrocarbon]] chains connected by single bonds alone ([[Saturated fat|saturated fatty acids]]) or by both double and single bonds ([[Unsaturated fat|unsaturated fatty acids]]). Fats are needed for construction and maintenance of [[cell membrane]]s, to maintain a stable body temperature, and to sustain the health of skin and hair. Because the body does not manufacture certain fatty acids (termed [[essential fatty acid]]s), they must be obtained through one's diet.
* [[Alcoholic drink|Ethanol]] is not an essential nutrient, but it does provide calories. The [[United States Department of Agriculture]] uses a figure of {{convert|6.93|kcal|lk=in|}} per gram of alcohol ({{convert|5.47|kcal|disp=or|abbr=on}} per [[millilitre|ml]]) for calculating food energy.<ref name=USDA>{{cite web|title=Composition of Foods Raw, Processed, Prepared USDA National Nutrient Database for Standard Reference, Release 26 Documentation and User Guide|url=http://www.ars.usda.gov/sp2UserFiles/Place/12354500/Data/SR26/sr26_doc.pdf|publisher=[[USDA]]|page=14|date=August 2013}}</ref> For [[distilled spirit]]s, a standard serving in the U.S. is {{cvt|1.5|USoz|order=flip}}, which at 40% ethanol (80 [[Alcohol proof|proof]]) would be 14 grams and 98 calories.

{| class="wikitable"
|+
!Biomolecule
!Kilocalories per 1 gram<ref>{{cite web|url=http://www.fao.org/docrep/006/Y5022E/y5022e04.htm|title=Chapter 3: Calculation Of The Energy Content Of Foods – Energy Conversion Factors|publisher=Food and Agriculture Organization of the United Nations|access-date=30 March 2017}}</ref>
|-
|Protein
|4
|-
|Carbohydrate
|4
|-
|Ethanol
|7<ref name=USDA/>
|-
|Fat
|9
|}