How City Living Influences ADHD-Related Obesity

Researchers from New York University’s Tandon School of Engineering and Italy’s Istituto Superiore di Sanità have discovered how urban environments influence the connection between attention-deficit/hyperactivity disorder (ADHD) and obesity.

Published in the journal PLOS Complex Systems, the study offers new insights into tackling this growing public health challenge by targeting specific urban conditions.

Using a novel engineering-based approach rooted in urban scaling laws, the researchers analyzed public health data from 915 U.S. cities to uncover how ADHD contributes to obesity. Urban scaling laws, a framework from complexity science, describe how features of cities change with population size, much like how biological traits scale with body size.

The research revealed that both ADHD and obesity decrease sublinearly with population size: as cities grow, the per-capita prevalence declines. Conversely, access to mental health services and higher education increases superlinearly, rising faster than city size.

“Urban scaling and causal discovery methods allow us to see relationships that traditional health research might miss,” senior author Maurizio Porfiri, an institute professor at NYU Tandon who also serves as a director of the NYU Center for Urban Science + Progress (CUSP), said in a news release.

To account for city-specific deviations from expected health outcomes, the team introduced Scale-Adjusted Metropolitan Indicators (SAMIs). These indicators measure how much a city deviates from urban scaling predictions, highlighting variations such as unexpectedly low obesity rates in smaller cities or insufficient mental health access in larger ones.

“Without accounting for how city size naturally affects health metrics, we’d misattribute success or failure to the wrong factors. By filtering out these population effects first, we can identify the true causal pathways linking ADHD to obesity — and more importantly, how urban environments modify these relationships,” added Tian Gan, a doctoral student in mechanical engineering at NYU Tandon.

The study’s findings suggest that ADHD leads to higher physical inactivity, subsequently increasing obesity. Moreover, access to mental health care and higher education correlates with better physical activity levels and health outcomes.

“This approach reveals precise intervention points that wouldn’t be apparent otherwise,” added Simone Macrì, a senior scientist at the Istituto Superiore di Sanità.

Regional discrepancies also emerged from the SAMIs analysis.

Cities in the Southeastern and Southwestern United States displayed greater disparities in ADHD and obesity prevalence, mental health access and food insecurity than other regions. Neighboring cities often differed significantly, suggesting that local policies and resources could either amplify or mitigate these health risks.

“Regional averages can mask a lot of variation,” Porfiri added. “The SAMIs let us see which cities are punching above or below their weight. It’s not just about how big a city is — it’s about how it uses its resources. With this kind of insight, policymakers can target investments in mental health care, education and physical activity to break the link between ADHD and obesity where it’s strongest.”

To ensure the robustness of their findings, the team analyzed data from over 19,000 children across the United States from the National Survey of Children’s Health. The same patterns emerged: children with more severe ADHD were more likely to be obese, especially in households with lower physical activity and educational levels.

This study follows earlier research by Porfiri and his collaborators exploring firearm ownership and gun violence across U.S. cities, further demonstrating how urban scaling frameworks can challenge traditional assumptions and guide public policy.

Source: NYU Tandon School of Engineering