Allison Wu, MD, MPH, is a general pediatric gastroenterologist at Boston Children’s Hospital and an assistant professor of pediatrics at Harvard Medical School.

Allison Wu, MD, MPH

How Food Access Shapes Childhood Obesity Risk

 remains one of the most pressing public health challenges in the United States, with growing recognition that its roots extend far beyond individual behavior. Increasing attention is being turned to the broader food environment, both at the neighborhood and household levels, as a key driver of long-term health outcomes.

0:00:13 – Defining food access vs food availability

0:01:0 – Study design and main findings

0:02:40 – Critical windows for intervention

0:04:05 – Role of gastroenterologists and team-based care

0:05:15 – Policy and “food is medicine” advocacy

New research presented by Allison Wu, MD, MPH, a general pediatric gastroenterologist at Boston Children’s Hospital and an assistant professor of pediatrics at Harvard Medical School​, at Digestive Disease Week (DDW) 2026 offers important insight into how these factors intersect to shape obesity risk over time.

In a large retrospective cohort study of nearly 14,000 children aged 2 to 11 years across Mass General Brigham-affiliated sites, she and colleagues examined how neighborhood food access and household food security influence body mass index (BMI) trajectories and obesity risk. Using geocoded residential data linked to the USDA Food Access Research Atlas, the study identified children living in low-income, low-vehicle (LILV) neighborhoods, areas where access to supermarkets is limited.

Over a 5-year follow-up period spanning 2019 to 2024, residence in these neighborhoods was associated with significantly higher BMI z-scores and an increased risk of obesity.

Of note, these effects were not immediate but emerged over time. Children living in LILV neighborhoods had a nearly 2-fold increased risk of obesity by age 10 compared to peers in areas with better food access, even after adjusting for insurance status. Parallel findings were observed at the household level, where children from food-insecure households also demonstrated higher BMI trajectories and elevated obesity risk, reinforcing the independent and additive roles of these exposures.

The study also underscores the importance of timing in intervention strategies. While differences in BMI were not apparent in early childhood, disparities became significant later, particularly in older children and adolescents. This suggests that early life remains a critical window for prevention, even before measurable differences emerge.

“I think of the critical windows for intervention as 2-fold. One is in early childhood thinking of obesity prevention. Even though we didn't see these effects at age 5, obesity prevention needs to be an area of focus, so intervening early on in life,” Wu said. “I think of the first 1000 days of life as being an important period to prevent obesity and promote optimal health, and then later on, early adolescence is another critical window for intervention.”

For gastroenterologists, these findings carry direct clinical relevance. Specialists often encounter the downstream effects of obesity, including 

metabolic dysfunction-associated steatotic liver disease

. This positions them as important touchpoints for screening and intervention. However, Wu stressed that addressing food access challenges requires a team-based approach.

“Working with primary care physicians, working with our dietitians, social work, other patient health navigators, is critical because it does not by any means rely on the gastroenterologist alone, and we have found a team-based approach is what's most productive and collaborative in helping navigate healthy food access, at least in terms of children and for families,” she explained.

Looking ahead, the findings support a multilevel strategy to combat childhood obesity that integrates clinical screening with community-based interventions and policy-level changes. Expanding access to nutrition support programs, including “food is medicine” initiatives and Medicaid-covered services, may play a critical role in bridging gaps.

Editors’ note: Wu reports no relevant disclosures.

US Centers for Disease Control and Prevention. Childhood Obesity Facts. April 2, 2024. Accessed May 2, 2026. 

https://www.cdc.gov/obesity/childhood-obesity-facts/childhood-obesity-facts.html

Wu A, Arris IM, Luo M, et al. MULTILEVEL ASSOCIATIONS OF THE FOOD ENVIRONMENT WITH CHILD BODY MASS INDEX AND OBESITY. Presented at Digestive Disease Week (DDW) 2026 in Chicago, IL, May 2-5, 2026.

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Wu describes her research linking low food access and food insecurity to higher childhood obesity risk, highlighting the need for early, multilevel prevention strategies.

Allison Wu, MD, MPH

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