September 20, 2021
2 min read
Bekelman reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.
Children living in the Midwest region of the U.S. have a higher BMI z score compared with those living in the Northeast, whereas children from the South and West have lower BMI z scores than the Northeast, according to study data.
Significant differences in BMI z score were found among four U.S. regions after adjusting for sociodemographic factors. Traci A. Bekelman, PhD, MPH, a research assistant professor in the department of epidemiology at the Colorado School of Public Health, said the findings reveal how geographic region can influence children’s BMI.
“Understanding regional influences can inform targeted efforts to mitigate BMI-related disparities among children,” Bekelman told Healio. “For example, regional variation in policies and programs that support participation of female children in organized sports may help explain why we see sex differences in BMI in some regions but not others.”
Bekelman and colleagues analyzed data from 25 cohorts in the Environmental Influences on Child Health Outcomes (ECHO) program. Children born between 2000 and 2018 were included if they had a recorded weight at birth available as well as BMI data for at least one other time point prior to age 15 years. Height and weight data were used to calculate sex-specific BMI z scores. Children were categorized based on ZIP code. Data on race and ethnicity and maternal education were also collected. The findings were published in Obesity.
Traci A. Bekelman, PhD, MPH
There were 14,313 children with 85,428 anthropometric measurements included in the study. Children from the West (beta = –0.14; 95% CI, –0.19 to –0.09) and from the South (beta = –0.12; 95% CI, –0.16 to –0.08) had lower mean BMI z scores compared with those living in the Northeast after adjusting for sociodemographic factors. Children living in the Midwest had a higher BMI z score compared with those from the Northeast (beta = 0.09; 95% CI, 0.05-0.14).
In a subset of 8,566 children with data on maternal education at birth available, no difference between the South and Northeast region was observed after additionally adjusting for maternal education. BMI z score differences strengthened in the West region (beta = –0.22; 95% CI, –0.29 to –0.16) and Midwest region (beta = 0.17; 95% CI, 0.11-0.23) compared with the Northeast.
In the Midwest and West, boys had a lower BMI z score compared with girls, whereas there was no difference by sex in the South or Northeast. Non-Hispanic Black children had a higher mean BMI z score compared with non-Hispanic white children in all regions except the West. Hispanic Black children had a greater BMI z score compared with non-Hispanic white children in the Northeast and Midwest, and Hispanic white children had a greater mean BMI z score than non-Hispanic white children in the South and West. Children whose mothers had less than a high school degree had a higher mean BMI z score compared with children with mothers with a college degree.
“We were surprised that we only found differences in BMI by child sex or race and ethnicity in some regions, but not others,” Bekelman said. “This raises questions about region-specific influences on child BMI, and how some regional factors may buffer against or exacerbate health disparities.”
Bekelman said more research must be conducted to explore why BMI varies by location and how regional environments and policies can impact a child’s BMI. Research is also needed on how BMI by race and ethnicity differs by region.
“Understanding regional influences on BMI may boost efforts to head off health disparities among children,” Bekelman said.
For more information:
Traci A. Bekelman, PhD, MPH, can be reached at firstname.lastname@example.org.