Childhood obesity benefit at 2 years rebounds at 4 years
An intervention program aimed at preventing childhood obesity in a region of Australia lowered BMI z scores and obesity prevalence during the first 2 years of the trial, but not in the subsequent 2 years, according to study data.
“No intervention effect for the primary outcome BMI z score or overweight or obesity was observed for intervention communities compared with control communities over the 4 years of the trial,” Steven Allender, PhD, Hon MFPH, a professor of public health and founding director of the Global Obesity Centre at Deakin University in Melbourne, Australia, and colleagues wrote in a study published in Obesity. “Although we observed a statistically significant reduction in the prevalence of overweight and obesity in intervention communities in the first 2 years (2015-2017), this was followed by a large increase in the final 2-year period against a backdrop of no change in control communities. Positive effects of the intervention were observed for takeaway consumption, water consumption among girls and packaged snacks among boys.”
Researchers recruited primary schools in 10 communities located on the southwest coast of Victoria, Australia, to participate in the Whole of Systems Trial of Prevention Strategies for Childhood Obesity (WHO STOPS). The intervention was a five-step, community systems-based approach in which community leaders and members identified and took actions to prevent childhood obesity among children aged 5 to 12 years. Five communities were randomly assigned to begin the intervention in late 2015, and five communities served as controls due to delays in beginning the intervention. All children in grades two, four and six who had not opted out of the study and were available on the day of baseline data collection were enrolled. Height and weight were collected from April to June in 2015, 2017 and 2019. Students in grades four and six also self-reported physical activity and sedentary behavior, completed a dietary questionnaire for food intake and answered a pediatric quality of life questionnaire.
No differences in BMI z score with intervention
Of the primary schools invited, 73% participated in 2015, 69% in 2017 and 63% in 2019. Student participation rates were 80% in 2015, 81% in 2017 and 79% in 2019.
There were no differences between the intervention and control communities in BMI z score change between 2015 and 2017 or 2015 and 2019. A reduction in BMI z score for the intervention communities was observed from 2015 to 2017, followed by an increase from 2017 to 2019. BMI z score remained stable in the control communities throughout the study period.
In intervention communities, the prevalence of children with overweight or obesity fell from 35.5% in 2015 to 31.5% in 2017 before increasing to 40.4% in 2019. The control communities had no significant change in prevalence during the study period.
Several factors may have caused the BMI z score to increase in the intervention communities in the second 2-year period of the study, according to the researchers. The impact of bushfires and other natural disasters may have reduced resources, in intervention communities may have adopted a sense of complacency after the BMI z score drop in 2017, the intervention communities may have reached a peak in capacity or engagement, and childhood obesity increased in Victoria during 2018 and 2019.
“These interventions should plan to mitigate unforeseen social and economic shocks that may distract community efforts,” the researchers wrote. “For WHO STOPS, bushfire brought this issue into stark relief. To be more effective, community interventions should be supported by larger auspice organizations, such as health services or local government, and they should be considered a priority across community leadership.”
No increase in takeaway food
The number of children who reported meeting physical activity guidelines increased by 8.2% in the intervention communities, with no change in the control communities. The intervention communities did not have a change in the consumption of takeaway food during the study period, whereas takeaway food consumption increased in the control communities. The number of girls in intervention communities drinking five or more glasses of water per day increased 18.1% from 2015 to 2017 and increased 11.8% from 2017 to 2019. The percentage of boys in the intervention communities who reported eating less than one packaged snack per day was 11.4% higher in 2017 and 12.2% higher in 2019 compared with baseline.
Children in the intervention communities reported improvements in psychosocial quality of life score in 2019, physical quality of life score in 2017 and 2019, and global quality of life in 2017 and 2019 compared with control and relative to 2015.
“WHO STOPS reduced obesity prevalence over 2 years, and over 4 years helped a majority of children keep their takeaway intake low and sustained health-related quality of life in a context in which this was declining,” the researchers wrote. “Results varied with gender and age group, indicating that single-behavior, single-setting interventions are unlikely to generate the level of change required to improve child health or prevent obesity across the spectrum of childhood. Rather, interventions need to adapt to children’s needs considering age, gender and the capacity or limitations of the surrounding systems.”