What are the causes of obesity in children

Obviously fat? How parents influence the weight of their children - The wrong diet and insufficient exercise are not the only causes of obesity

The numbers are alarming: every second adult in Germany is overweight. Often the weight problems start in childhood. Every sixth child in this country is now overweight, and many are even obese - a serious problem that preventive measures are intended to counteract. "Unfortunately, these preventive measures have so far not been crowned with great success," says Prof. Dr. Manfred Müller from the Institute for Human Nutrition and Food Science in Kiel. The reason: There are numerous factors that determine the weight of children and that have so far not been taken into account by preventive measures. "A child does not only become overweight when it eats the wrong way or does not exercise enough - the causes of obesity in childhood and adolescence are more complex." That is why the scientists in the PreVENT research association, which is funded by the Federal Ministry of Education and Research ( BMBF) as part of the Obesity Competence Network, the causes of obesity in children and adolescents and develop new preventive measures.

What factors increase the risk of obesity in children? "The analysis of the data from more than 34,000 children and adolescents from Germany has shown that, for example, the parents' cigarette consumption is an important risk factor for obesity in children," explains Professor Müller. Because children whose parents smoke have a 30 percent higher risk of becoming overweight compared to children of non-smokers. And the blue haze is important for weight problems very early on: If a woman smokes during her pregnancy, the baby's risk of becoming overweight as a child is increased by 40 percent.

"However, there is no physiological connection between the parents' smoking habits and the excess weight of the children," emphasizes Professor Müller. Rather, smoking, like eating habits, is often an indirect indicator of the parents' social and educational status. "Because overweight occurs particularly often in families with little education," explains Professor Müller. "And it is precisely a low level of education that often represents a barrier to successful preventive measures." According to the results of the evaluation, children of single parents and children with a migration background also have an increased risk of becoming overweight.

Too much television makes you fat

The time that children are allowed to spend in front of the television or computer also determines their body size: If children sit in front of the screen for more than an hour a day, their risk of becoming fat increases. "Compared to children who are allowed to watch TV or play on the computer for less than an hour a day, children who spend three hours there, for example, have an 80 percent higher risk of obesity," says Professor Müller.

Fat parents have fat children

The weight of the parents, which reflects their biological disposition as well as their diet and lifestyle, is also important for the risk of obesity in children: Children and adolescents whose parents are overweight have a risk that is up to 80 percent higher, even once Getting overweight. "If the parents are obese, the children's risk of becoming overweight is increased by as much as 300 percent compared to children with parents of normal weight."

Prevention begins with pregnancy

Another risk factor for obesity in childhood is, for example, if mothers put on more than 17 kilograms during pregnancy - a weight gain of twelve to 16 kilograms is considered normal. Likewise, a baby's birth weight of more than 3,890 grams for girls and 4,030 grams for boys is a risk of later obesity.

In order to develop suitable preventive measures from these findings, the researchers are currently calculating how the everyday life of children and their parents would have to change in order to protect the offspring from being overweight. “It is clear that future prevention programs should no longer be limited to a healthy diet and adequate exercise. Rather, we have to reach out to the children's parents and strengthen their health literacy during family planning and during pregnancy, ”says Professor Müller.

If all parents now stop smoking, all expectant mothers do not smoke during pregnancy and all children and adolescents spend less than an hour a day in front of the television or computer - would there really be significantly fewer children than before? “It is precisely these scenarios that we are currently calculating in our models in order to develop the effectiveness and usefulness of new and targeted preventive measures. Unfortunately, viewed realistically, we have to assume that our measures will certainly never reach more than a third of the children and parents, ”says Professor Müller. Obesity in childhood and adolescence will probably remain a problem - "but hopefully a decreasing one".

Overweight or Obesity? The body mass index

Doctors fundamentally differentiate between overweight and severe overweight, i.e. obesity or obesity. Whether a person is under, normal, overweight or obese can be differentiated with the body mass index, or BMI for short. The body weight in kilograms is divided by the square of the height in meters. The World Health Organization (WHO) recommends fixed limit values ​​for the definition of overweight and obesity for adults: from a BMI of 25 kg / m² or more an adult is overweight and from a BMI of 30 kg / m² is obese.

The BMI is also used to define overweight and obesity in childhood and adolescence. However, unlike adults, no fixed BMI limit values ​​can be set for children and adolescents, as the BMI changes during development. Therefore, age and gender must be taken into account in children and adolescents. Tables provide information about the result.

The BMI limits were determined statistically for children: According to this, a child is overweight if its BMI is higher than 90 percent of the children from a comparison group of German children whose BMI was measured between 1985 and 1999. Children are considered obese if their BMI is higher than 97 percent of the children in this comparison group.

Competence Network Obesity

Since 2008 the BMBF has been funding the "Disease-related Competence Network Obesity". Networked nationwide, scientists research, for example, the causes and risk factors of obesity. In addition, they develop and improve the diagnosis, therapy and prevention of obesity and secondary diseases. The obesity competence network is initially set up for three years and is then to be continued and expanded in three further funding phases up to 2020. The spokesman for the competence network is Prof. Dr. Hans Hauner from the Technical University of Munich. The competence network consists of eight research associations. One of these alliances is the Interdisciplinary Consortium for the Prevention of Obesity in Children and Adolescents (PreVENT), which is headed by Prof. Dr. Manfred Müller from the Christian Albrechts University in Kiel is coordinated.

Contact Person:
Prof. Dr. Manfred J. Mueller
Institute for Human Nutrition and Food Science
Christian Albrechts University in Kiel
Düsternbrooker Weg 17
24105 Kiel
Tel .: 0431 880-5670
Fax: 0431 880-5679
Email: [email protected]