Underweight can have various causes and also has different medical relevance depending on the person affected. In many cases, however, underweight is a risk factor for malnutrition and therefore often requires appropriate intervention measures.
What is underweight?
In medicine, underweight is spoken of when a person’s body weight falls below a defined minimum value. In medicine, underweight is spoken of when a person’s body weight falls below a defined minimum value. A common measure for determining underweight is the so-called Body Mass Index (BMI); this can be determined on the basis of a person’s height and weight. If a person’s Body Mass Index falls below the defined value of 18.5, they are underweight according to medical definition. According to the German Federal Statistical Office, around 2 million people are affected by underweight throughout Germany; the majority of these people are female. Although in many cases underweight is also accompanied by malnutrition, this need not always be the case: for example, some people with a predisposition to medically defined underweight may well be adequately nourished.
Causes
The causes of underweight can be manifold; for example, prevailing food shortages are among the most important causes of underweight worldwide: due to the undersupply of nutrients, affected individuals experience a loss of body fat and also muscle mass, which ultimately leads to underweight. Furthermore, underweight can be caused by diseases, functional disorders or intolerances: Diseases that can lead to underweight include chronic diseases of the gastrointestinal tract. Functional disorders that can cause underweight include hyperthyroidism, for example. Finally, corresponding intolerances that can hide behind underweight include lactose, fructose or other food intolerances. But not only physical illnesses lead to underweight; mental illnesses, such as eating disorders, can also cause underweight. And last but not least, the common beauty ideal of a slim body also contributes to many cases of underweight.
Diseases with this symptom
- Hyperthyroidism
- Anorexia athletica
- Anorexia
- Bulimia
- Food intolerance
- Lactose intolerance
Diagnosis and course
If underweight is accompanied by malnutrition, the underweight can lead to various sequelae and complications in its course. For example, there is an undersupply of minerals and vitamins; in children, such an undersupply can lead to mental and physical developmental disorders, among other things. In the course of its development, underweight can also make those affected more susceptible to infections and reduce their life expectancy. In women, for example, underweight can impair the menstrual cycle and thus limit fertility. Underweight can be diagnosed using various indices, such as the Body Mass Index (BMI) described above. To enable a physician to determine whether malnutrition is also present in addition to underweight, procedures such as bioelectrical impedance analysis (BIA) can be used: This can be used, for example, to determine the ratio of body fat to body fluids.
Complications
Persistent underweight can lead to various complications. First, too low a weight weakens the body and leads to deficiency symptoms such as exhaustion and reduced performance. Especially during periods of stress or illness, rapid debilitation and feelings of lassitude occur. Underweight people are generally more susceptible to illness, especially infectious diseases, and have a higher risk of complications. Slowed metabolism also increases the risk of various gastrointestinal diseases. Chronic underweight also slows recovery, [wound healing disorders|deteriorates wound healing]] and can lead to an overall decreased life expectancy. Bones are also put under considerable stress by permanent underweight; a possible consequence is osteoporosis, which in turn is associated with multifaceted symptoms.In rare cases, chronic emaciation can lead to unconsciousness and, in the further course, death. In children and adolescents, growth slows; possible complications include malformations and chronic immune deficiency. In women, underweight can delay menstrual bleeding and reduce fertility in the long term. Because of the many complications, persistent underweight should always be discussed with a physician. Underweight after a prolonged illness or diet, on the other hand, is usually unproblematic; complications include intermittent dizziness and mild fatigue.
When should you see a doctor?
It is often not easy at the beginning to distinguish pathogenic underweight from slimness. However, exactly here runs the borderline, which makes a visit to the doctor necessary. The existing uncertainties are reinforced by the fact that no clear boundaries exist in human medicine. The question of when underweight requiring treatment exists is disputed in the human medical literature. However, the unanimous view is that the body mass index (BMI) provides an initial guide. Most physicians recommend treatment when a BMI of 18 or 19 is present. Others draw the line a little earlier (19.5) or even later (17). As a rule, however, it is better to see a doctor earlier as a precaution. Otherwise, there is a risk of serious consequences. First of all, it makes sense to see your family doctor. He or she acts as the first point of contact and will refer the patient to specialists if necessary. This also applies if an eating disorder is suspected, which may require complementary psychotherapeutic treatment.
Treatment and therapy
If the underweight in an affected person requires treatment, the basis for targeted therapy is usually a detailed diagnosis of the causes of the underweight. The aim of medical treatment is then to combat existing causes. If, for example, underweight is caused by illnesses or functional disorders, one of the treatment goals is usually to treat the problems that are causing the underweight. For example, hyperthyroidism, which leads to underweight, can be treated with medication; in this way, the production of thyroid hormones can be inhibited. This drug treatment is often followed by surgical reduction of the thyroid gland or therapy with radioactive iodine. If severe anorexia (eating disorder) is the cause of underweight, artificial nutrition may be necessary in some cases to ensure that the affected person receives sufficient nutrients. In a next step, correct eating behavior must then often be trained, which often takes place as an inpatient and as part of a psychotherapeutic treatment concept. If people have a predisposition to underweight and would like to gain weight, one treatment component may be, for example, nutritional counseling that provides information about calorie-containing diets.
Outlook and prognosis
As a rule, underweight can be combated relatively easily and does not necessarily need to be treated by a doctor. If the underweight is caused by the patient eating too little food, the affected person must make sure to eat more himself. This can eliminate the underweight in the long term. If the underweight is not treated, in the worst case it can lead to bulimia, anorexia and finally to death. Usually, sufferers can also be treated in special clinics and facility if the parents or the friends cannot convince the affected person to seek treatment. Prolonged underweight damages organs and can partially limit their function. The patient often feels weakened and complains of headaches and other ailments. It also increases susceptibility to certain infections and diseases. In many cases, treatment leads to success. However, the success of treatment depends heavily on the patient’s will and therefore cannot be universally predicted.
Prevention
Preventing being underweight can be important, especially in the case of chronic diseases, in order not to put additional strain on the body. This is possible, for example, through conscious and, if necessary, high-calorie food. And also a consistent medical treatment of basic diseases can counteract underweight preventively.
You can do it yourself
While many people struggle with too many pounds on the scale, some suffer from equally burdensome underweight. Being underweight can also increasingly restrict everyday life. A suitable diet can help eliminate this problem. To gain weight, it is important to create a positive energy balance. This means taking in more calories than the body needs for its everyday functions. However, unhealthy calorie bombs such as ice cream, chocolate and co. should be cut out. Although they provide many calories, they have a negative health value. There are many foods that have a high calorie density and yet are beneficial to health. Underweight people should include in their diet foods that provide valuable fats. These include nuts, avocados, coconut milk, trail mix and natural oils such as olive oil. Valuable carbohydrate sources include millet, buckwheat, oats, teff, quinoa, spelt and whole grains. Proteins can be well covered by chia seeds, eggs, high-quality meat, millet and legumes. Consumption of fatty sea fish such as herring, mackerel or salmon is also recommended. In addition, it is recommended to stimulate the apetite before meals. For this purpose, bitter substances such as bitter star or apples can be taken to help. It is important not to drink too much during the meal, as the feeling of satiety is mainly influenced by the stomach filling.
