Caloric deficit

A caloric 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 reducing calories consumed by lower food intake, such as by dieting.^[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.^{[citation needed]}

To reduce 1 kg of weight, about 7000 kcal deficit is required.^[9]

Nutritionally complete meal replacements can be used to minimize malnutrition.^[10]

See also[]

• Weight loss
• Diet
• Nutrition
• Exercise

References[]