Energy balance (nutrition)

In nutritional science, the energy balance or energy balance is the difference between a person's energy supply and energy needs . If more energy is supplied than consumed, the energy balance is positive. On the other hand, if less energy is consumed than consumed, it is negative. With a positive energy balance you increase, with a negative energy balance you increase.

Connections

According to the standard textbooks of nutritional science, the energy balance has a significant influence on the development of body weight: In the end, too much energy is stored in body fat, regardless of whether it is obtained from fat or carbohydrates . Proteins, on the other hand, are only stored to a very limited extent. If, on the other hand, a weight reduction is to be achieved, achieving a negative energy balance is crucial.

Energy is not only used for physical exercise, but also for the so-called basal metabolic rate . This includes the supply of the liver and the skeletal muscles with about 26% each, followed by the brain with 18%, the heart with 9% and the kidneys with 7%. The remaining 14% are accounted for by the other organs. In addition, energy is used to build, remodel and break down cells and for all metabolic processes in the body.

Control loops

The body's own control circuits, the most important factors of which are appetite and hunger , control the use of energy and thus the energy balance. There are people whose metabolism utilizes food better ("good feed converters"). Others have less efficient energy utilization and / or dissipate excessive energy in the form of heat or body excretions ( intestinal flora ). In the event of illness, control loops can be disturbed and too much or (for example in the case of obesity ) too little energy can be dissipated. Some drugs also disrupt the control loop. If the energy supply is low (for example in the case of malnutrition or anorexia ), the energy can be balanced by the body's own reserves or redistributed through over-exploitation. Well trained muscles are more efficient, work more efficiently and need less energy for the same performance. What is to be judged as normal or healthy or sick is very complex.

Balance sheet

If the consumption exceeds the energy absorbed through nutrition, the body can only cover this deficit by attacking its own reserves. In dietetics , therefore, a change in diet to reduce intake and additional consumption through sporting activities is recommended. This also has the advantage that it bypasses the habituation effect.

However, exercise as an instrument often seems to go unused: Nutrition experts criticize a sharp decrease in physical activity and thus an increasing risk of obesity . Research has shown that this primarily affects children and adolescents: Children who spent more than five hours a day watching television had a more than eight-fold increased risk of becoming overweight.

Studies

A detailed contemporary criticism of the energy balance model as used in dietetics can be found in Gary Taubes and Robert Lustig .

Fredrik Nyström examined the consequences of massive overeating in the case of sedentary lifestyle as in Super Size Me under laboratory conditions. In addition, 18 students doubled their energy intake through fast food and avoided moving. According to the energy balance model, all students should have increased massively. This was only partially the case. The subjects put on weight to different degrees. Only one of the participants in the study reached the critical limit of 15 percent weight gain and had to stop the study at 150 kg. Nyström sees this result as proof that an unhealthy lifestyle, as long as it is not maintained in the long term, does not have to cause permanent damage to healthy people.

A study published in Science showed that it matters not just how much energy you ingest and how much you move, but also how the body reacts to excess energy.

literature

• Ludwig Weissbecker: Diseases of the energy balance. In: Ludwig Heilmeyer (ed.): Textbook of internal medicine. Springer-Verlag, Berlin / Göttingen / Heidelberg 1955; 2nd edition ibid 1961, pp. 1099–1111.

Web links

• The calories and body weight. Article in the NZZ

Individual evidence

1. ↑ The calories and body weight. Article in the NZZ
2. ↑ Gary Taubes : Good Calories, Bad Calories. 2007, ISBN 9781400040780
3. ↑ Robert Lustig : Fat Chance. The Bitter Truth About Sugar. 2012, ISBN 0007514123
4. ↑ Kate Douglas: "Super size me" revisited - under lab conditions. New Scientist , Issue 2588, January 27, 2007
5. ↑ New Scientist No. 2588, January 27, 2007
6. ^ JA Levine, NL Eberhardt, MD Jensen: Role of nonexercise activity thermogenesis in resistance to fat gain in humans. In: Science. Volume 283, Number 5399, January 1999, pp. 212-214, ISSN  0036-8075 . PMID 9880251 .

This article is about a health issue. It is not used for self-diagnosis and does not replace a diagnosis by a doctor. Please note the information on health issues !