# The body size increases after 16 years

## Formulas for calculating height: how big will my child get?

More and more XXL kids: In the last 20 years, male teenagers have grown an average of two and girls even 2.5 centimeters taller. If you too would like to know how big your child will one day, you can use the formula for calculating the genetic target size to determine this.

### Percentile curve - determination of average growth

In order to be able to precisely determine the average course of a child's growth, the doctor creates a line diagram, the so-called percentile curve. It is used to assess the development of height and weight in children and adolescents. The growth of children of the same age is always compared. When taking the first measurement, the doctor therefore refers to the time the child has developed up to the time of birth.

In order to be able to statistically determine deviations in growth, the value most frequently determined in an age group is defined as the average value. In a growth curve, this value is referred to as the 50th size percentile. The normal range for a child's body growth is the range between the 3rd and 97th percentile.

With the help of the percentile curve, the doctor can immediately determine whether the child is inside or outside the usual growth area (source: Forum Wachsen)

With the help of this list you can classify the percentiles and the associated values:

• 97th percentile: Only three percent of their peers are taller and 97 percent shorter than your child.
• 85th percentile: 15 percent of their peers are taller and 85 percent shorter than your child.
• 50th percentile: 50 percent of their peers are taller and 50 percent are shorter. So your child is right in the middle.
• 15th percentile: 85 percent of their peers are taller and 15 percent shorter than your child.
• 3rd percentile: 97 percent of their peers are taller, only 3 percent shorter than your child.

### Children grow faster than they used to

To date, the German Institute for Standardization has published almost 30,000 standards. This also includes the series of standards on human body measurements with the number 33402-2. The height of people has been systematically recorded as the basis for norms since 1986. However, the data originated from around 1970. Since then, the Germans have grown and the standard had to be completely revised. According to this, 90 percent of German women are between 153 and 172 centimeters tall. 90 percent of German men are between 165 and 186 centimeters tall.

The seven to ten year olds are reportedly one to 1.5 centimeters taller than they were in the 1970s. The size of the newborns between 1984 and 1997 changed only slightly by plus 0.2 centimeters. This means that the growth rate increased in childhood. After puberty, this trend is no longer so pronounced. Overall, the increase in size observed in the 20th century has now slowed down. 120 years ago, young people were still 15 centimeters shorter than they are today.

### How big is my child? Possibilities of determination

There are different options for calculating the future height of the child.

1. One variant is a medical examination. The left hand is X-rayed. From this, the bone age can be determined, which in turn provides information on growth retardation and the final size.
2. Another possibility is the calculation based on the height of the parents. The following formulas apply:

For boys:

Final height of the child =
(Height of mother + height of father + 13): 2

For girls:

Final height of the child =
(Height of mother + height of father - 13): 2

For example, if the mother is 170 cm tall and the father is 180 cm tall, the result is the size (170 cm + 180 cm + 13): 2 = 181.5 cm for boys and (170 cm + 180 cm - 13): 2 = 168 , 5 cm for girls.

3. A third possibility is the calculation based on the height of the child taking into account the annual growth:

Future size of child = current size + (remaining years of growth * growth per year)

For example, if the child is seven years old and 120 centimeters tall, assuming the end of the growth phase at the age of 16, the calculation is: 120 cm + (9 * 5 cm) = 165 cm.

### How fast does a child grow?

Children grow at different speeds depending on their age. Since the factors for growth are different, only guidelines can be given. In the first year of life, a newborn baby grows to around 25 centimeters. Then growth slows down. In the second year of life, the size increases by about 10 to 20 centimeters, in the following year by 7-10 centimeters.

In the fourth year of life the child grows by an average of 5-7 centimeters, after which the growth levels off at around 5 centimeters. Growth spurts can occur again between the sixth and eighth birthday. From the age of eleven, the process slows down until it comes to a new flare-up with the onset of puberty.

### How is body size influenced?

The growth of the children is stimulated by the growth hormone somatropin. This hormone is produced by the pituitary gland and is usually released during sleep. It controls both bone growth and muscle building.

But the following factors also have an influence on your child's height:

• Genetic predisposition
• The child's diet
• health status
• Exercise volume
• Diseases
• Get enough sleep

Diet plays an important role in this, as the energy for growth is taken in through food. If there is a lack of nutrients, growth can be impaired if the body does not have sufficient energy available. A balanced diet is therefore just as important as a loving environment and adequate medical care.

In addition, the bones gain stability through a healthy amount of exercise. An excessive urge to move, however, can also have a negative effect.

Furthermore, various congenital organ diseases and metabolic disorders can have a lasting effect on growth. If your child is unusually small and skinny, we recommend a medical examination.

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### Hormones are not always behind stunted growth

Professor Wabitsch from Ulm University Hospital is a pediatric endocrinologist, i.e. a specialist in growth disorders. He is specifically looking for the reasons. Because behind a growth disorder, among other things, there can be problems with the kidneys, the intestines or the heart. Sometimes malnutrition or psychosocial neglect, in the worst case even a tumor.

First of all, the children are measured, the course and bone development are assessed and the rate of growth in centimeters per year is observed. With the help of blood tests and other tests, the specialists can then determine whether a growth hormone deficiency is prevalent and what the reasons are.

The therapy naturally also depends on this diagnosis. If a child is too young or constitutionally delayed, they are usually given some time. But if the cause is a hormone defect or a hormone disorder, then a replacement is provided - at least until the growth is complete. "If there is a growth hormone deficiency, it is good if the substitution treatment is started well before the onset of puberty," explains Wabitsch to t-online.de.

### The treatment: an individual decision

There is no one-size-fits-all answer as to whether or not short stature and tall stature in a child should be treated with growth hormone. Each family makes this decision individually. It is important to speak to the specialists in detail in advance of a possible therapy.

If the body size is below the age-appropriate normal range, there is short stature. The lower limit of the norm is represented by the third percentile curve. If, on the other hand, a girl threatens to grow taller than 185 cm and a boy taller than 205 cm, one speaks of tall stature.

Growth therapy with sex estroids can be used to slow down excessive growth. The therapy should begin in girls at a height of 170 to 172 centimeters and in boys at a height of 182 to 185 centimeters.

If short stature has been diagnosed, treatment with the growth hormone STH can be useful. The growth hormone used in the treatment is an endogenous substance that is artificially produced.

In general, the following applies: Treatment is more effective if it is started early.

Important NOTE: The information is in no way a substitute for professional advice or treatment by trained and recognized doctors. The contents of t-online cannot and must not be used to independently make diagnoses or start treatments.