Background

In a recently-published study, results demonstrated that residence in low-income, low-food access neighborhoods in early life was linked to higher subsequent child body mass index (BMI) and higher risk of obesity and severe obesity.

Published in JAMA Pediatrics, the study authors noted that limited access to healthy foods because of lack of access is a public health concern. Led by Izzuddin M. Aris, PhD, of the Department of Population Medicine at Harvard Medical School and the Harvard Pilgrim Health Care Institute, the investigative team stated that food insecurity prevalence in United States' households with children younger than 18 years of age increased from 12.5% in 2021 to 17.3% in 2022.

"Concurrently, the prevalence of childhood obesity, another major public health concern, has been steadily rising," wrote Aris and colleagues. "We sought to determine the extent to which neighborhood food access (primary aim) and caregiver food insecurity (secondary aim) during pregnancy and early childhood may contribute to childhood obesity risk."

Study details and results

The study used data from cohorts that participated in the nationwide Environmental Influences on Child Health Outcomes consortium from January 1, 1994 to march 31, 2023. Inclusion criteria included a geocoded residential address in pregnancy (mean 32.4 gestational weeks) or early childhood (mean 4.3 years), in addition to the child's BMI.

Low-income, low-food access neighborhoods were defined as those where the nearest supermarket was more than 0.5 miles away for urban areas or more than 10 miles for rural areas. BMI z score, obesity, and severe obesity from age 0 to 15 years were the main outcomes of the trial. Obesity was defined as age- and sex-specific BMI ≥95th percentile and severe obesity was age- and sex-specific BMI ≥120% of the 95th percentile.

"To ensure the exposure preceded the outcome, we modeled repeated BMI z scores or obesity measures obtained at or after the residential address date for low-income, low–food access exposure," said the authors. "We used these models to estimate mean predicted BMI z score and probabilities of obesity and severe obesity over time for low-income, low–food access status, holding covariates constant at their mean values and setting the random effects to [0]."

Across 55 cohorts and 28,359 children, 23.2% resided in low-income, low-food access neighborhoods in pregnancy and 24.4% in early childhood. Residents in these neighborhoods in pregnancy—compared to non-low income, low-food access residents—were associated with higher BMI z scores at the following ages:

• 5 years - (β, 0.07; 95% CI, 0.03-0.11)
• 10 years - (β, 0.11; 95% CI, 0.06-0.17)
• 15 years - (β, 0.16; 95% CI, 0.07-0.24)

Higher obesity risk was observed under this association at:

• 5 years - (risk ratio [RR], 1.37; 95% CI, 1.21-1.55)
• 10 years - (RR, 1.71; 95% CI, 1.37-2.12)
• 15 years - (RR, 2.08; 95% CI, 1.53-2.83)

Higher severe obesity risk was observed under. this association at:

5 years - (RR, 1.21; 95% CI, 0.95-1.53)

10 years - (RR, 1.54; 95% CI, 1.20-1.99)

15 years - (RR, 1.92; 95% CI, 1.32-2.80)

Authors noted that findings were similar for these neighborhoods in early childhood, and that the associations were "robust to alternative definitions of low income and low food access and additional adjustment for prenatal characteristics associated with child obesity."

Conclusion

Findings demonstrated that low-income, low-food access neighborhoods in early life was associated with higher BMI z scores and increased risk of obesity and severe obesity, from childhood to adolescence.

"Given the long-term sequelae associated with child obesity,12,13 our findings support a focus on investments or strategies to improve healthful food access in early life," the authors concluded. In addition, they called for extended research to investigate if such strategies would be effective in preventing child obesity.

Reference:

Aris IM, Wu AJ, Lin PD, et al. Neighborhood Food Access in Early Life and Trajectories of Child Body Mass Index and Obesity. JAMA Pediatr. Published online September 16, 2024. doi:10.1001/jamapediatrics.2024.3459