Young children who attend daycare on a regular basis are 50% more likely to be overweight compared to those who stayed at home with their parents, according to a study by researchers at the University of Montreal and the CHU Sainte-Justine Hospital Research Centre.

"We found that children whose primary care arrangement between 1.5 and 4 years was in daycare-center or with an extended family member were around 50% more likely to be overweight or obese between the ages of 4-10 years compared to those cared for at home by their parents," said Dr. Marie-Claude Geoffroy, who led the study. "This difference cannot be explained by known risk factors such as socioeconomic status of the parents, breastfeeding, body mass index of the mother, or employment status of the mother."

The researchers studied 1,649 families with children born in 1997-1998 in Québec. The sample was representative of the majority of Québec children. Mothers were interviewed about the care of their children at 1.5 years, 2.5 years, 3.5 years, and 4 years. The children were classified according to the type of care in which they had spent the most total hours, i.e., in a 'daycare centre' (30%), in 'family daycare' (35%), with an 'extended family member' (11%), with a 'nanny' (5%), or with their 'parents' (19%). During the six years that followed, the researchers measured the children's weight and height. Children with excessive weight or obesity were identified using international standards (IOTF).

To date, the mechanisms responsible for the increased proportion of overweight children in some child care situations remains unknown. "Diet and physical activity are avenues to follow," says Dr. Sylvana Côté, who co-directed the study. "Parents don't have to worry; however, I suggest to parents they ensure their children eat well and get enough physical activity, whether at home or at daycare."

The researchers believe that daycare has the potential to reduce weight problems in children, possibly through the promotion of physical activity and healthy eating. "The enormous potential of the impact of daycare on the nutritional health of children 2-5 years of age was also noted by the Extenso unit of the University of Montreal Nutrition Reference Centre, which has developed a Web portal specifically devoted to children in daycare," said Dr. Jean Séguin, who also co-directed this study.