An obsession with food: Prader Willi syndrome

Prader-Willi syndrome is a fairly rare condition in which children develop an insatiable appetite, which can lead to enormous obesity. These children need less energy than healthy children and due to congenital muscle weakness they will exercise less than average, which increases the risk of becoming extremely fat. What exactly does Prader-Willi syndrome mean and how can it be treated?

The discovery of Prader-Willi syndrome

In 1956, this condition was described by doctors Prader, Labhart and Willi. It was found that there was a combination of muscle weakness, an uncontrollable urge to eat together with some external features and these features together could not be a coincidence. It later turned out that this condition is the result of a genetic abnormality in which a small piece of hereditary material (DNA) is missing on one of the chromosomes located in the cell nucleus. Because this abnormality occurs by chance during the formation of the sperm cells, the chance of this occurring is very small. The disease is therefore very rare and common in both boys and girls. Approximately 10 babies are born in the Netherlands each year with the rare Prader-Willi syndrome.


At birth
A baby with Prader-Willi syndrome has a low birth weight and weight gain will not occur quickly in the beginning. This often results in severe muscle weakness ( hypotonia ). As a result, the baby will move little, cry little and softly and sleep a lot. Due to the poor sucking reflex and difficulty swallowing, the baby will drink little and very slowly.
The external characteristics are as follows:

  • Narrow forehead
  • Narrow nose
  • Almond-shaped eyes
  • Thin triangular upper lip
  • Little developed sexual organs

In children
As the child gets older, the eating pattern changes significantly. From the age of one, there is a large increase in appetite, even an obsession with food, including a tendency to eat abnormal things such as soap or other objects. Due to the body’s relatively low energy requirements, people are often seriously overweight ( obese). Furthermore, there is a mild to moderate delay in intellectual development and a delay in the development of motor skills.
Furthermore, the following characteristics apply:

  • Easy-going character with occasional tantrums
  • Less sensitive to pain
  • Less likely to have fever with infections
  • Small hands and feet
  • A lot of scratching and picking at wounds, resulting in scars

In adolescents and adults
Due to a mild to moderate intellectual disability, learning problems persist even in adulthood. Sexual development does not start or only starts late . Someone with Prader-Willi syndrome is usually infertile. The body length remains below average. For men this is on average 1.55 meters and for women 1.50 meters. Due to the strong and sometimes insatiable appetite, obesity is usually present. Usually there is also a need to take a nap during the day. Some adults also develop psychological problems such as outbursts of anger, periods of depressive or even psychotic behavior.


Tube feeding for babies
In the first months after birth, tube feeding is often necessary because babies with Prader-Willi syndrome find it very difficult to drink. Things usually get better from the age of six months onwards. After one year, children can develop a virtually insatiable appetite with an obsession with food. Their energy needs, on the other hand, are about 30 percent below average.
Due to congenital muscle weakness, the child moves little. If physiotherapy is started at infancy, muscle tone can be improved considerably. On average, the child only starts sitting around the age of 12 months and walks for the first time around the age of 30 months. There are children with Prader-Willi syndrome who have virtually normal motor development.
Speech therapy
The development of speech and language development is usually quite slow due to muscle weakness in the mouth. Speech therapy at a young age is useful for both speech and the sucking reflex.

Intellectual development

Because of the usually delayed intellectual development, children with this condition usually go to special education. After attending mostly special secondary education and sometimes individual further training, some adults can manage quite independently. Due to uncontrollable eating behavior, many adults rely on guidance in both living and working. In addition to learning difficulties, people often think abstractly, arithmetic is difficult and more time is needed to handle matters.


Young children often appear happy and warm-hearted. As they get older, they may have bouts of moodiness, stubbornness and irritability. This can be difficult for the educator because there are disappointments for the child as a result of the disability. The uncontrollable urge to eat often causes the most problems. It is a great challenge for the parent to control the child’s insatiable appetite in combination with obesity. The child continues to feel hungry despite a full stomach.


If weight can be somewhat controlled, life expectancy is normal. This will be very difficult because someone with Prader-Willi syndrome thinks about food 24 hours a day. If you are overweight, joint problems, lung disease, high blood pressure and diabetes may develop. If you are extremely overweight, sleep and breathing disorders such as sleep apnea can develop. This causes breathing to stop during sleep.

Healing is not possible

Prader-Willi syndrome is caused by an abnormality in the DNA. As a result, this syndrome cannot be cured. At most, some symptoms can be controlled. The main treatment is growth hormone treatment. Furthermore, specific treatments can be given, such as surgical treatment of undescended testicles, or hormonal therapy for absent or delayed pubertal development. Performing a gastric reduction generally does not have permanent results.