Biology:Caloric deficit
A calorie deficit (British English: calorific deficit) is any shortage in the number of calories consumed relative to the number of calories needed for maintenance of current body weight (energy homeostasis).
A deficit can be created by decreasing calories consumed by lower food intake, such as by swapping high-calorie foods for lower calorie options or by reducing portion sizes.[1] A deficit can also be created by increasing output (burning calories) without a corresponding increase in input. Increased output is created by increasing physical activity,[2] from increased caloric requirements necessary to heal an injury,[3] or from growth.[4] There are also some substances, including caffeine, which can create a small (3-5%)[5] increase in caloric expenditure, via a variety of pathways that include increasing physical activity levels and increasing thermogenesis (heat output), and/or by reducing caloric input via appetite suppression.[6][7] Drugs and herbal treatments creating a more extreme metabolic effect exist; however, they cause extreme increases of heart rate and thermogenesis that can cause death in even very healthy and athletic individuals, and these drugs are not widely sold.[7][8]
As the calories required for energy homeostasis decreases as the organism's mass decreases, if a moderate deficit is maintained eventually a new (lower) weight will be reached and maintained, and the organism will no longer be at caloric deficit.[2] A permanent severe deficit, on the other hand, which contains too few calories to maintain a healthy weight level, will eventually result in starvation and death.
To reduce 1 kg (2.2 lbs) of weight, about 7000 kcal deficit is required.[9][10]
See also
- Weight loss
- Diet
- Nutrition
- Exercise
References
- ↑ "Counting calories: Get back to weight-loss basics". Mayo Clinic. http://www.mayoclinic.org/healthy-living/weight-loss/in-depth/calories/art-20048065.
- ↑ 2.0 2.1 Redman, LM; Heilbronn, LK; Martin, CK; de Jonge, L; Williamson, DA; Delany, JP; Ravussin, E (February 9, 2009). "Metabolic and Behavioral Compensations in Response to Caloric Restriction: Implications for the Maintenance of Weight Loss". PLOS ONE 4 (2): e4377. doi:10.1371/journal.pone.0004377. PMID 19198647. Bibcode: 2009PLoSO...4.4377R.
- ↑ "Nutrition for Injury Recovery: Part 3" (in en-US). 2013-06-21. https://www.precisionnutrition.com/nutrition-for-injury-part-3.
- ↑ "CALORIC NEEDS". http://www.utmb.edu/pedi_ed/CORE/Nutrition/page_08.htm.
- ↑ Dulloo, A. G.; Geissler, C. A.; Horton, T.; Collins, A.; Miller, D. S. (1989-01-01). "Normal caffeine consumption: influence on thermogenesis and daily energy expenditure in lean and postobese human volunteers.". The American Journal of Clinical Nutrition 49 (1): 44–50. doi:10.1093/ajcn/49.1.44. ISSN 0002-9165. PMID 2912010. http://ajcn.nutrition.org/content/49/1/44.
- ↑ Schrader, Patrick; Panek, Leah M.; Temple, Jennifer L. (2013). "Acute and chronic caffeine administration increases physical activity in sedentary adults". Nutrition Research (Elsevier BV) 33 (6): 457–463. doi:10.1016/j.nutres.2013.04.003. ISSN 0271-5317. PMID 23746561.
- ↑ 7.0 7.1 "Dietary Supplements for Weight Loss — Health Professional Fact Sheet". https://ods.od.nih.gov/factsheets/WeightLoss-HealthProfessional/.
- ↑ Lu, Yuan-qiang; Jiang, Jiu-kun; Huang, Wei-dong (March 2011). "Clinical features and treatment in patients with acute 2,4-dinitrophenol poisoning". Journal of Zhejiang University Science B 12 (3): 189–192. doi:10.1631/jzus.B1000265. ISSN 1673-1581. PMID 21370503.
- ↑ Joslin, Elliott Proctor; Kahn, C. Ronald (2005-01-01). Joslin's Diabetes Mellitus: Edited by C. Ronald Kahn ... [et Al..]. Lippincott Williams & Wilkins. ISBN 9780781727969. https://books.google.com/books?id=ohgjG0qAvfgC.
- ↑ Shah, Khushali (April 4, 2021). "The Ultimate Calorie Deficit Guide For Weight Loss - Healthy And Khush". https://healthyandkhush.com/calorie-deficit/.
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