Editing Calorie restriction (section)

==Dietary guidelines==

Caloric intake control, and reduction for [[obesity|overweight]] individuals, is recommended by US dietary guidelines and science-based societies.<ref name="USDietaryGuidelines2015">{{Cite web |last=US Department of Health and Human Services. |date=2017 |title=2015–2020 Dietary Guidelines for Americans - health.gov |url=https://health.gov/dietaryguidelines/2015/ |access-date=30 September 2019 |website=health.gov |publisher=Skyhorse Publishing Inc.}}</ref><ref name="AACAHA2019">{{Cite journal |display-authors=6 |vauthors=Arnett DK, Blumenthal RS, Albert MA, Buroker AB, Goldberger ZD, Hahn EJ, Himmelfarb CD, Khera A, Lloyd-Jones D, McEvoy JW, Michos ED, Miedema MD, Muñoz D, Smith SC, Virani SS, Williams KA, Yeboah J, Ziaeian B |date=September 2019 |title=2019 ACC/AHA Guideline on the Primary Prevention of Cardiovascular Disease: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines |journal=Circulation |volume=140 |issue=11 |pages=e596–e646 |doi=10.1161/CIR.0000000000000678 |pmc=7734661 |pmid=30879355 |doi-access=free}}</ref><ref name="NICE2019-obesity">{{Cite web |title=Obesity: maintaining a healthy weight and preventing excess weight gain |url=https://pathways.nice.org.uk/pathways/obesity/obesity-maintaining-a-healthy-weight-and-preventing-excess-weight-gain#content=view-node%3Anodes-diet |website=pathways.nice.org.uk}}</ref><ref name="USGuidelines2013">{{Cite journal |display-authors=6 |vauthors=Jensen MD, Ryan DH, Apovian CM, Ard JD, Comuzzie AG, Donato KA, Hu FB, Hubbard VS, Jakicic JM, Kushner RF, Loria CM, Millen BE, Nonas CA, Pi-Sunyer FX, Stevens J, Stevens VJ, Wadden TA, Wolfe BM, Yanovski SZ, Jordan HS, Kendall KA, Lux LJ, Mentor-Marcel R, Morgan LC, Trisolini MG, Wnek J, Anderson JL, Halperin JL, Albert NM, Bozkurt B, Brindis RG, Curtis LH, DeMets D, Hochman JS, Kovacs RJ, Ohman EM, Pressler SJ, Sellke FW, Shen WK, Smith SC, Tomaselli GF |date=June 2014 |title=2013 AHA/ACC/TOS guideline for the management of overweight and obesity in adults: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and The Obesity Society |journal=Circulation |volume=129 |issue=25 Suppl 2 |pages=S102–S138 |doi=10.1161/01.cir.0000437739.71477.ee |pmc=5819889 |pmid=24222017}}</ref><ref name="NICE2019">{{Cite web |title=Diet - NICE Pathways |url=https://pathways.nice.org.uk/pathways/diet#path=view%3A/pathways/diet/dietary-interventions-and-advice-for-adults.xml&content=view-node%3Anodes-reducing-calorie-intake |website=pathways.nice.org.uk}}</ref><ref name="Garvey2016">{{Cite journal |display-authors=6 |vauthors=Garvey WT, Mechanick JI, Brett EM, Garber AJ, Hurley DL, Jastreboff AM, Nadolsky K, Pessah-Pollack R, Plodkowski R |date=July 2016 |title=American Association of Clinical Endocrinologists and American College of Endocrinology Comprehensive Clinical Practice Guidelines for Medical Care of Patients with Obesity |journal=Endocrine Practice |volume=22 |issue=Suppl 3 |pages=1–203 |doi=10.4158/EP161365.GL |pmid=27219496 |doi-access=free}}</ref>

Calorie restriction is recommended for people with [[diabetes]]<ref name="ADA2019">{{Cite journal |last=American Diabetes Association |date=January 2019 |title=5. Lifestyle Management: ''Standards of Medical Care in Diabetes-2019'' |journal=Diabetes Care |volume=42 |issue=Suppl 1 |pages=S46–S60 |doi=10.2337/dc19-S005 |pmid=30559231 |doi-access=free}}</ref><ref name="ADA2018">{{Cite journal |display-authors=6 |vauthors=Evert AB, Dennison M, Gardner CD, Garvey WT, Lau KH, MacLeod J, Mitri J, Pereira RF, Rawlings K, Robinson S, Saslow L, Uelmen S, Urbanski PB, Yancy WS |date=May 2019 |title=Nutrition Therapy for Adults With Diabetes or Prediabetes: A Consensus Report |journal=Diabetes Care |type=Professional society guidelines |volume=42 |issue=5 |pages=731–754 |doi=10.2337/dci19-0014 |pmc=7011201 |pmid=31000505 |doi-access=free}}</ref> and prediabetes,<ref name="ADA2018" /> in combination with physical exercise and a weight loss goal of 5-15% for diabetes and 7-10% for prediabetes to prevent progression to diabetes.<ref name="ADA2018" /> Mild calorie restriction may be beneficial for pregnant women to reduce weight gain (without weight loss) and reduce perinatal risks for both the mother and child.<ref name="Glazier2018">{{Cite journal |vauthors=Glazier JD, Hayes DJ, Hussain S, D'Souza SW, Whitcombe J, Heazell AE, Ashton N |date=October 2018 |title=The effect of Ramadan fasting during pregnancy on perinatal outcomes: a systematic review and meta-analysis |journal=BMC Pregnancy and Childbirth |volume=18 |issue=1 |pages=421 |doi=10.1186/s12884-018-2048-y |pmc=6202808 |pmid=30359228 |doi-access=free}}</ref><ref name="Than2012">{{Cite journal |display-authors=6 |vauthors=Thangaratinam S, Rogozinska E, Jolly K, Glinkowski S, Roseboom T, Tomlinson JW, Kunz R, Mol BW, Coomarasamy A, Khan KS |date=May 2012 |title=Effects of interventions in pregnancy on maternal weight and obstetric outcomes: meta-analysis of randomised evidence |journal=BMJ |volume=344 |pages=e2088 |doi=10.1136/bmj.e2088 |pmc=3355191 |pmid=22596383}}</ref> For [[management of obesity|overweight or obese]] individuals, calorie restriction may improve health through weight loss, although a gradual weight regain of {{convert|1|-|2|kg|abbr=on}} per year may occur.<ref name="AACAHA2019" /><ref name="USGuidelines2013" />

===Risks of malnutrition===
The term "calorie restriction" as used in [[gerontology|the study of aging]] refers to dietary regimens that reduce calorie intake without incurring [[malnutrition]].<ref name=lee/> If a restricted diet is not designed to include essential nutrients, malnutrition may result in serious deleterious effects, as shown in the [[Minnesota Starvation Experiment]].<ref name="Keys A 1950" /> This study was conducted during [[World War II]] on a group of lean men, who restricted their calorie intake by 45%<ref>Keys A 1950, p. 114.</ref> for six months and composed roughly 77% of their diet with carbohydrates.<ref name="Keys A 1950">Keys A, Brozek J, Henschels A & Mickelsen O & Taylor H. The Biology of Human Starvation, 1950. University of Minnesota Press, Minneapolis</ref> As expected, this malnutrition resulted in [[Starvation response|metabolic adaptations]], such as decreased body fat, improved lipid profile, and decreased resting heart rate. The experiment also caused negative effects, such as [[anemia]], [[edema]], [[Muscle atrophy|muscle wasting]], [[weakness]], [[dizziness]], [[irritability]], [[lethargy]], and depression.<ref name="Keys A 1950" />

Typical low-calorie diets may not supply sufficient nutrient intake that is typically included in a calorie restriction diet.<ref name="St. Jeor et al, 2001">{{Cite journal |vauthors=St Jeor ST, Howard BV, Prewitt TE, Bovee V, Bazzarre T, Eckel RH |date=October 2001 |title=Dietary protein and weight reduction: a statement for healthcare professionals from the Nutrition Committee of the Council on Nutrition, Physical Activity, and Metabolism of the American Heart Association |journal=Circulation |volume=104 |issue=15 |pages=1869–1874 |doi=10.1161/hc4001.096152 |pmid=11591629 |doi-access=free}}</ref><ref name="de Souza et al, 2008">{{Cite journal |vauthors=de Souza RJ, Swain JF, Appel LJ, Sacks FM |date=July 2008 |title=Alternatives for macronutrient intake and chronic disease: a comparison of the OmniHeart diets with popular diets and with dietary recommendations |journal=The American Journal of Clinical Nutrition |volume=88 |issue=1 |pages=1–11 |doi=10.1093/ajcn/88.1.1 |pmc=2674146 |pmid=18614716}}</ref><ref name="Ma et al, 2007">{{Cite journal |vauthors=Ma Y, Pagoto SL, Griffith JA, Merriam PA, Ockene IS, Hafner AR, Olendzki BC |date=October 2007 |title=A dietary quality comparison of popular weight-loss plans |journal=Journal of the American Dietetic Association |volume=107 |issue=10 |pages=1786–1791 |doi=10.1016/j.jada.2007.07.013 |pmc=2040023 |pmid=17904938}}</ref>

===Possible side effects===
People losing weight during calorie restriction risk developing [[side effect]]s, such as [[cold sensitivity]], [[menstrual irregularities]], [[infertility]], or hormonal changes.<ref>{{Cite journal |vauthors=Marzetti E, Wohlgemuth SE, Anton SD, Bernabei R, Carter CS, Leeuwenburgh C |date=November 2009 |title=Cellular mechanisms of cardioprotection by calorie restriction: state of the science and future perspectives |journal=Clinics in Geriatric Medicine |volume=25 |issue=4 |pages=715–32, ix |doi=10.1016/j.cger.2009.07.002 |pmc=2786899 |pmid=19944269}}</ref>