According to a new study, children who attended centre-based childcare between 1 and 4 years of age had a lower body mass index (BMI) and were less likely to be overweight or obese in later childhood than children who had non-parental childcare that was home-based or provided by relatives or nannies.

The study was published in the journal, American Society for Nutrition. "Although more research is needed, our findings suggest that centre-based childcare may help level socioeconomic-related health disadvantages for children from low-income families," said Michaela Kucab, a graduate student at St. Michael's Hospital, a site of Unity Health Toronto, and the University of Toronto, both in Canada.

"We hope this work draws much-needed attention to prioritising centre-based childcare while also encouraging future research on the impact of centre-based childcare on growth and other important health and developmental outcomes in children," said the study's senior author Jonathon Maguire, MD, from St. Michael's Hospital.

Previous studies evaluating the relationship between childcare attendance and obesity have primarily focused on comparing parental care with non-parental childcare settings.

"Given the increase in dual-income families and the fact that many families are faced with making decisions about childcare, our work aimed to evaluate non-parental childcare settings," said Kucab. "We hope that our findings might help parents and policymakers advocate for and prioritise the best childcare environments for children."

The researchers analysed data collected from a large, multicultural sample of healthy Canadian children using The Applied Research Group for Kids (TARGet Kids!) primary care research network based in Toronto. They compared the BMI of children at age 4 to 10 years old for those who had attended centre-based childcare between 1 and 4 years of age versus those who attended other non-parental childcare environments.

"One advantage of using data from TARGetKids! is that it began in 2008 and is ongoing, whereas many previous studies have used data collected decades ago," said Kucab. "This may have allowed us to capture the effects of the many improvements implemented by modern childcare programs."

The detailed questionnaire data collected in TARGetKids made it possible for the researchers to account for numerous variables and to explore important factors such as socioeconomic status and the number of hours per week that each child spent in a childcare environment.

The researchers found that children who attended centre-based care full-time had a 0.11 lower BMI at ages 4 and 7 and were less likely to be overweight or obese at 4 years old compared to children who attended non-centre-based care. Children from lower-income families who attended centre-based care full-time had a 0.32 lower BMI and were less likely to be overweight or obese at 10 years of age compared to those who attended non-centre-based care.

"Our findings make sense because health behaviours are developed in early childhood and may be influenced by the environments that children encounter," said Kucab. "There may be underlying factors and care practices that differ between childcare arrangements that help explain the effects on childhood growth."

For example, childcare centres in both Canada and the US must follow nutrition guidelines and adhere to other health-behaviour guidelines related to physical activity and rest. They also have licensed early childhood educators who supervise childcare practices and make sure programs provide routines appropriate for growing children.

Although these factors may contribute to the findings, the researchers note that the study was observational and not designed to assess cause-and-effect relationships, adding that clinical trials would be needed to confirm causality.

The researchers are now expanding on their work by studying the relationship between centre-based childcare in young children and later nutritional risk, dietary intake and eating behaviours.

They are also working to implement a clinical trial, called Nutrition Recommendation Intervention Trials in Children's Health Care (NuRISH), that will leverage the methods used by TARGet Kids! to evaluate whether connecting families with centre-based childcare through the primary health-care system can improve the physical, mental, nutritional and developmental health of children from low-income families.

Researchers say findings from the trial could be used to inform policy decisions about using centre-based childcare as an intervention to improve health and productivity over the life course.