The most incisive guide to issues facing the American family today . . . An invaluable resource for anyone wishing to stay on the cutting edge of research on family trends.

-W. Bradford Wilcox
Associate Professor of Sociology, University of Virginia 

The Chubby Only Child

Because it will surely incubate serious long-term health issues, the epidemic in child obesity alarms health authorities in the United States and Europe. Understandably, these authorities are now looking closely at children’s diet. Perhaps they should look not only at what children eat but also at the family circumstances in which they do their eating. A new European study identifies the absence of siblings as a prime predictor of weight problems among children. It now looks like no mere coincidence that birth rates were dropping at the same time that child obesity rates were climbing.

Conducted by a large team of researchers, this new study brings together the analytical acumen of scholars from a wide range of institutions—including Columbia University in the United States, the Universitat de Barcelona in Spain, the Université Paris Descartes in France, Radboud University Nijmegen in the Netherlands, the University of Cagliari in Italy, and the University of Koblenz-Landau in Germany. Together, these scholars pore over data collected in 2010 for 5,206 children between the ages of 6 and 11 years old, all enrolled in schools in Italy, Germany, the Netherlands, Bulgaria, Lithuania, and Turkey. 

These data establish, first of all, that “the prevalence of overweight and obesity in school children in 2010 was high and deserves attention from public health policy-makers.” More specifically, about one in six of the children surveyed (15.6%) was overweight; about one in twenty (4.9%) was obese.  

Through statistical analysis, the researchers identify both geography and gender as predictors of weight problems (child weight problems were more common in Eastern Europe than in Western Europe, and more common among boys than girls). Understandably, the analysis also highlighted the role of a “sedentary lifestyle” in causing weight problems (the number of hours a child spent watching TV each week predicted the likelihood of such problems).

But family circumstances also emerge as an important predictor of weight problems. Such problems showed up more often among children whose mothers reported “frequent unguided behaviours” than among children whose mothers reported that such behaviors were infrequent.

But at a time when demographers report a birth dearth throughout Europe and the United States, one finding perhaps deserves special attention: the researchers conclude that compared to peers with siblings, children who have no siblings are almost half-again more likely to be overweight or obese (adjusted Odds Ratio of 1.40). The researchers remark, “Our findings show that children with no siblings are at higher risk of overweight and obesity,” noting that these findings align with those from earlier studies.

But the researchers confess some uncertainty as to the reason that children without siblings are particularly likely to develop weight problems. Obviously, in some families, “the number of children at home could decrease the availability of food,” as these families split food resources among siblings.

However, the researchers point to earlier studies concluding that “having siblings is associated with higher consumption of soft drinks, sweets and snacks in young children.” On the other hand, the researchers reason, “the presence of other siblings might . . . stimulate play and therefore increase the time spent on physical activity.”

“The role of siblings with respect to childhood overweight is unclear,” remark the researchers, who call for “further research” on the matter.

But even without such additional research, we know enough to doubt whether public-health officials will succeed in driving down the incidence of child weight problems so long as birth rates remain low. 

(Beatriz Olaya et al., “Country-level and Individual Correlates of Overweight and Obesity among Primary School Children: A Cross-Sectional Study in Seven European Countries,” BMC Public Health 15 [2015]: 575, Web.)