A single child has a more than 50 percent higher risk of being overweight or obese than those with siblings, as borne out by a study of 12,700 children in eight European countries, including Sweden.
The study was conducted under the framework of the European research project Identification and prevention of dietary and lifestyle-induced health effects in children and infants (IDEFICS), focusing on diet, lifestyle and obesity and their effects on children aged two to nine years.
The children’s BMI (body mass index) was linked to a parental questionnaire that included questions relating to the children’s eating habits, TV viewing habits and amount of outdoor play time, the journal Nutrition and Diabetes reported.
The study shows that only children play outside less often, live in households with lower levels of education more often, and are more likely to have televisions in their bedrooms, said study co-author Monica Hunsberger, researcher at the Sahlgrenska Academy, University of Gothenburg, Sweden.
But even when we take these factors into account, the correlation between singleton status and overweight is strong. Being an only child appears to be a risk factor for overweight independent of the factors we thought might explain the difference, adds Hunsberger, according to a Gothenburg statement.
The fact that only children are more susceptible to obesity may be due to differences in individual family environment and family structure that we were not able to measure in sufficient detail, said Lauren Lissner, researcher at the Sahlgrenska.
Over 22 million children in Europe are estimated to be overweight. The study shows that obesity among children in general is three times more common in southern countries such as Italy, Spain and Cyprus than in Sweden and other northern countries.