Attention-deficit/hyperactivity disorder (ADHD) might contribute to obesity by reducing physical activity—a relationship that can also be mediated by the features of the urban environment in which a person lives.

That is the conclusion of a new study published in PLOS Complex Systems by Tian Gan, Rayan Succar, and Maurizio Porfiri of the Tandon School of Engineering at New York University, U.S., and Simone Macrì of the Italian National Institute of Health, Italy.

For years, scientists have suspected that impulsivity—including conditions like ADHD—may increase the risk of obesity, but much of the evidence has focused on individual traits and behaviors, placing limited attention toward environmental and social factors.