Underweight

Underweight can have different causes and is medically relevant 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, we speak of underweight when the body weight of a person falls below a defined minimum value. A common parameter for determining underweight is the so-called Body Mass Index (BMI); this can be determined based on a person's height and weight.

If a person's body mass index falls below the defined value of 18.5, the medical definition means that they are underweight. According to the Federal Statistical Office, around 2 million people across Germany are affected by underweight; the majority of these people are female.

In many cases, underweight is also associated with malnutrition, but this does not always have to be the case: Some people with a predisposition to medically defined underweight can be adequately nourished.

causes

The causes of underweight can be many; For example, the prevailing food shortage around the world is one of the most important causes of underweight: Due to the insufficient supply of nutrients, those affected lose body fat and muscle mass, which ultimately leads to underweight.

Furthermore, underweight can be caused by illnesses, functional disorders or intolerance: illnesses that can lead to underweight are, for example, chronic diseases of the gastrointestinal tract. One of the functional disorders that can cause underweight is, for example, an overactive thyroid.

Corresponding intolerances that can be hidden behind being 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 being 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 & course

If underweight is accompanied by malnutrition, the underweight can lead to various sequelae and complications in its course. For example, there is an insufficient supply of minerals and vitamins; In children, such an undersupply can lead to mental and physical development disorders, among other things.

In its course, being underweight can also make those affected more susceptible to infections and reduce life expectancy. In women, for example, being underweight can interfere with the cycle and thus reduce fertility.

Underweight can be diagnosed using various indices, such as the Body Mass Index (BMI) described. So that a medical professional can determine whether there is also malnutrition in addition to being underweight, methods such as the so-called bioelectrical impedance analysis (BIA) can be used: This can be used to determine the ratio of body fat to body fluids.

Complications

Persistent underweight can lead to various complications. To begin with, a weight that is too low weakens the body and leads to deficiency symptoms such as exhaustion and reduced performance. Especially in times of stress or illness, there is rapid exhaustion and feelings of exhaustion.

People who are underweight are generally more prone to illness, especially infectious diseases, and have a higher risk of complications. The slowed metabolism also increases the risk of various gastrointestinal diseases. Chronic underweight also slows down recovery, [impaired wound healing worsens wound healing]] and can lead to a reduced life expectancy overall.

The bones are also significantly stressed by being permanently underweight; one possible consequence is osteoporosis, which in turn is associated with a variety of symptoms. In rare cases, chronic emaciation can lead to unconsciousness and later death. Growth slows down in children and adolescents; possible complications are malformations and chronic immune deficiency.

In women, being underweight can delay menstrual bleeding and reduce fertility in the long term. Due to the manifold complications, persistent underweight should always be discussed with a doctor. On the other hand, being underweight after a long illness or diet is usually unproblematic; Complications include intermittent dizziness and slight exhaustion.

When should you go to the doctor?

Often it is not easy to distinguish pathogenic underweight from slimness at the beginning. However, this is exactly where the limit runs, which makes a doctor's visit necessary. The existing uncertainties are exacerbated by the fact that there are no clear limits in human medicine.

The question of when there is underweight in need of treatment is controversial in the human medical literature. However, the unanimous opinion is that the body mass index (BMI) is a first reference point. Most health professionals recommend treatment if you have a BMI of 18 or 19. Others draw the line a little earlier (19.5) or later (17). As a rule, however, it is better to see a doctor earlier as a precaution. Otherwise there may be serious consequences.

First of all, it makes sense to see your family doctor. This acts as the first point of contact and will be referred to specialists if necessary. This also applies if there is a suspicion of an eating disorder that may require additional psychotherapeutic treatment.

Doctors & therapists in your area

Treatment & Therapy

If the underweight in an affected person needs treatment, the basis for a targeted therapy is usually a detailed diagnosis of the causes of the underweight. The aim of medical treatment is then to combat the underlying causes. For example, if an underweight is due to illnesses or functional disorders, one of the treatment goals is usually to treat these causative problems.

An overactive thyroid that leads to underweight, for example, can be treated with medication; so 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 reason for underweight, artificial nutrition may be necessary in some cases in order to ensure an adequate supply of nutrients for the person concerned.

In the next step, correct eating behavior often has to be trained, which is often done on an inpatient basis and as part of a psychotherapeutic treatment concept. If people have a predisposition to being underweight and would like to gain weight, a treatment module, for example nutritional advice, can provide information about a high-calorie diet.

Outlook & forecast

As a rule, underweight can be combated relatively easily and does not necessarily have to be treated by a doctor. If the underweight arises from the fact that the patient does not eat enough food, the person concerned must ensure that they eat more themselves. This can eliminate the underweight in the long term.

If the underweight is not treated, it can in the worst case lead to bulimia, anorexia and ultimately death. As a rule, those affected can also be treated in special clinics and facilities if the parents or friends cannot convince the affected person to receive treatment.

Organs are damaged by prolonged underweight and can partially limit their function. The patient often feels weak and complains of headaches and other complaints. It also increases the susceptibility to certain infections and diseases.

In many cases one treatment is successful. However, the success of the treatment depends heavily on the patient's will and can therefore not be universally predicted.

prevention

Preventing underweight can be important, especially in the case of chronic diseases, so as not to put additional strain on the body. This is possible, for example, through conscious and, if necessary, high-calorie eating. Consistent medical treatment of basic illnesses can also preventively counteract being underweight.

You can do that yourself

While many people struggle with too many pounds on the scales, some suffer from equally stressful underweight. Underweight can also increasingly restrict everyday life. Appropriate diet can help eliminate this problem. In order to gain weight, it is important to have a positive energy balance. This means that more calories have to be consumed than the body needs for its everyday functions.

However, unhealthy calorie bombs such as ice cream, chocolate and Co. should be avoided. Although they are high in calories, they have a negative health value. There are many foods that are high in calories and still beneficial for your health. Underweight people should include foods that provide valuable fats in their diet. These include nuts, avocados, coconut milk, trail mix and natural oils such as olive oil. Millet, buckwheat, oats, teff, quinoa, spelled and whole grains are valuable sources of carbohydrates. Proteins can be well covered by chia seeds, eggs, high quality meat, millet and legumes. The consumption of high-fat sea fish such as herring, mackerel or salmon is also recommended.

In addition, it is advisable to stimulate the appetite before meals. Bitter substances such as bitter star or apples can be used to help. It is important not to drink too much while eating, as the feeling of fullness is mainly influenced by the stomach filling.