Definition
Even if overweight is one of the main problems in our western world, underweight is at least as far-reaching a problem for those affected, which can have serious and terrible consequences. All too often, not only children have to listen to terms like “asparagus tarzan” or “beanpole”. According to the Federal Statistical Office, up to 2 million citizens in Germany are affected by underweight, especially women under 30 years of age.
In the USA over 3% and in France even almost 5% of the population are underweight. Underweight should not be confused with malnutrition, which is due to a lack of food intake and thus vitamins, proteins, fats and other building materials important for the body. Not every underweight person is therefore undernourished.
Malnutrition is the main cause of underweight, especially in developing countries and affects almost 50% of the population there. There are many other aspects and causes of underweight to consider. In addition to physical and psychological causes, the variations and moods of nature must always be considered and not every person with underweight is in need of treatment.
It is not always so easy to draw the line on underweight, even if one speaks of a BMI (=Body Mass Index) below 18.5 kg/m2 of underweight. A BMI of less than 17.5 kg/m2 is called pronounced underweight. From the age of 60, this limit is only drawn at a BMI of 22 kg/m2.
The Body Mass Index is the most commonly used scale in Germany for estimating body weight and is calculated using a formula based on height and body weight. However, its validity is now strongly criticized, since even high muscle percentages lead to incorrectly high overweight assessment. Particularly in children, a great deal of attention is paid to body weight as part of preventive medical checkups.
Here, however, not the BMI but the so-called age-appropriate percentiles are used as reference and measurement values. This involves comparing the children with many other children of the same age. The cause of morbid underweight is always a disproportion between the need and supply of nutrients, usually as a result of too little calorie intake.
The calorie value of a food indicates its energy supply value in the body and is printed on the packaging of many foods. In the body itself, leptin is the most important marker of current energy status. A good energy balance leads to the release of the hormone leptin in body fat cells.
Hormones can be found in the body as message transmitters in the blood. Leptin transmits the information whether there is enough energy available or whether the person concerned feels hunger when there is not enough energy. If no or less leptin is released due to a lack of energy, important functions in the body are downregulated and the deficiency symptoms occur.
Both with children, and with adults the underweight must have however no pathological or treatment-needy cause and by the individual metabolism and the personal physique plan these humans are slim and apparently too thin for their life time, without their body has problems with it. Nevertheless, all other physical causes must always be excluded in children and adults with underweight, because it is not uncommon for underweight to be caused by another disease and one should not jump to the conclusion that a genetic underweight exists. Often children are also classified as underweight in a preventive examination.
According to a study by the Robert Koch Institute, almost 4 percent of children under the age of 6 are underweight. This proportion will increase until the end of puberty. Often this finding is only temporary and the children are already within the weight norms for the respective age at the next preventive examination and a growth spurt with a lagging weight gain led to temporary underweight. Every child follows its own growth plan and when parents are asked, they often report underweight during their actual development. It is not only the numerical value alone but also the circumstances that determine, both in children and adults, whether further diagnosis of underweight is necessary.It is important not only to compare the child with its peers, but also to include in its decision-making process whether it is a fit, lively child with a great desire to move around or whether there are signs of a disorder such as tiredness, listlessness or even psychological abnormalities.
