Caloric deficit

A caloric deficit is any shortage in the amount of calories consumed relative to the amount of calories required for maintenance of current body weight (energy homeostasis).

A deficit can be created by reducing input/calories consumed (lower food intake, aka dieting).<ref>

Counting calories: Get back to weight-loss basics(link). {{{website}}}. Mayo Clinic.

Accessed 12 January 2019.

</ref> A deficit can also be created by increasing output without a corresponding increase in input. Increased output is created by increasing physical activity,<ref name=":0" /> from increased caloric requirements necessary to heal an injury, ^{(June 2019)}

or from growth.<ref>

CALORIC NEEDS(link). www.utmb.edu.

</ref> There are also some substances, including Caffeine, which can create a small (3-5%)<ref>Dulloo, A. G.,

 Normal caffeine consumption: influence on thermogenesis and daily energy expenditure in lean and postobese human volunteers., 
 The American Journal of Clinical Nutrition, 
 
 Vol. 49(Issue: 1),
 pp. 44–50,
 DOI: 10.1093/ajcn/49.1.44,
 PMID: 2912010,
 
 
 Full text,</ref> 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.<ref>Schrader, Patrick, 
 Acute and chronic caffeine administration increases physical activity in sedentary adults, 
 Nutrition Research, 
 2013,
 Vol. 33(Issue: 6),
 pp. 457–463,
 DOI: 10.1016/j.nutres.2013.04.003,</ref><ref name=":1">

Dietary Supplements for Weight Loss — Health Professional Fact Sheet(link). ods.od.nih.gov.

</ref> 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.<ref name=":1" /><ref>Lu, Yuan-qiang,

 Clinical features and treatment in patients with acute 2,4-dinitrophenol poisoning, 
 Journal of Zhejiang University. Science. B, 
 
 Vol. 12(Issue: 3),
 pp. 189–192,
 DOI: 10.1631/jzus.B1000265,
 PMID: 21370503,
 PMC: 3048933,</ref>

As the calories required for energy homeostasis decreases as the organisms'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.<ref name=":0">,

 Metabolic and Behavioral Compensations in Response to Caloric Restriction: Implications for the Maintenance of Weight Loss, 
 PLOS ONE, 
 
 Vol. 4,
 
 DOI: 10.1371/journal.pone.0004377,
 PMID: 19198647,
 PMC: 2634841,</ref>  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.

^{(June 2019)}

To reduce 1 kg of weight, about 7000 kcal deficit is required.<ref>Elliott Proctor,

 Joslin's Diabetes Mellitus: Edited by C. Ronald Kahn ... [et Al.].. online version, 
  
 Lippincott Williams & Wilkins, 
  
  
  
 ISBN 9780781727969,</ref>

See also

• Weight loss
• Diet
• Nutrition
• Exercise

References

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