Parents with one child are more likely to use food as a reward. (Photo: Colourbox)

Obesity risks for only children

An only child runs a 50 percent greater risk of becoming overweight than children with siblings, a new European study shows.

Europe has around 22 million overweight or obese children. Researchers studying overweight children have already probed their environment, genetic disposition and social factors but a new study focuses on family structure.

The study comprises data from eight European countries and nearly 13,000 children aged two to nine. The children were registered by age, gender, number of siblings, weight at birth and current weight. Researchers have also included their parents’ ages, BMIs and levels of education.

The results showed a 50 percent greater chance of overweight among only children.

Higher prevalence among older single children

The oldest only children in the study, aged six to nine, run an even greater risk of overweight − 70 percent. This means that the longer a child lives without siblings the greater the risk of getting fat.

Siblings are less likely to have problems with overweight. (Photo: Colourbox)

Among the youngest only children, those under six, the odds of becoming overweight increase by 30 percent against kids with brothers or sisters. Children in the Nordic countries tend to be slimmer than their counterparts to the south.

The researchers looked at the kids’ diet, how often they played outdoors and how much time they spent in front of TV or PC screens.

Many of the single-child parents use food as a reward and allow their kids to have TVs or computers in their bedrooms. The researchers think this could be a fat factor.

Only children are also less likely to live with both parents, they play less outdoors and consume more sugar, according to the study.

Monica Hunsberger (Photo: OHSU)

Having siblings reduces the risks of obesity, almost no matter how many children in a family.

The children in the study who have always had siblings enjoy slightly lower odds of becoming overweight than children who get a brother or sister later on. But this difference isn’t very significant.

Same results in Norway

Petur Benedikt Juliusson is a post doc at the University of Bergen’s Department of Clinical Medicine, who in 2010 made similar findings about children with siblings being less prone toward child obesity.

Nevertheless, Juliusson is somewhat critical of the methods used in the new European study:

“The study shows a prevalence of overweight among only children but among other things they haven’t found out why there are more overweight children in Southern Europe than here in the North.”

Nor has the study revealed all the reasons for an only child’s overweight:

“The tendency for only children to become overweight was prevalent even when they allowed for factors such as outdoor play, TVs in the bedroom, time spent in front of a screen, how often the parents rewarded the child with food and the children’s sugar consumption,” says Juliusson.

He would like to see more information about why single children run this greater risk.

The authors of the study have themselves commented on weaknesses in the basic data because it was the parents themselves who reported the facts about the family’s lifestyle.

Monika Hunsberger, a nutritionist and health researcher at the University of Gothenburg, Sweden, was involved in the European study.

She says the research project is one of the first in which the main focus is on obesity among only children and children with siblings. This wasn’t the case with the weight study from Bergen.

“Previously most of the research has been on psychological and physical factors, but we’ve viewed family structure and lifestyle as the most important.”

Hunsberger thinks insufficient research has been conducted on European children and stresses that the recent study is multinational.

How to avoid obesity

Children who suffer from obesity are more likely to develop type 2 diabetes, cardiovascular ailments and other chronic diseases.

“There are lots of things parents with an only child can do," says Hunsberger. "Keeping the child active is important in addition to a healthy diet with whole grain foods and lots of vegetables. They should also avoid using sweets as rewards."

The European researchers are now starting on a new five-year study. It will focus on the family’s role, both biologically and socially, as well as on children’s health.


Read the Norwegian version of this article at

Translated by: Glenn Ostling

External links

Related content
Powered by Labrador CMS