Walkable Cities, Healthier Lives: Why the Built Environment Matters
A landmark Nature study published in August 2025 has delivered some of the clearest evidence yet that our cities directly shape our health. By analysing smartphone data from over 2 million people in 1,609 U.S. cities, researchers demonstrated that walkability doesn’t just attract active people—it actively causes people to be more active.
What the Science Shows
The study tracked around 5,000 individuals who moved between U.S. cities, providing a unique before-and-after picture of how their activity levels changed. The results were striking:
- Moving to a more walkable city led to an average increase of 1,100 steps per day—equivalent to around 11 extra minutes of walking without intentional effort.
- In New York City, that difference rose to 1,400 steps per day. Conversely, those moving away from NYC lost the same amount.
- The additional steps were mostly brisk walking, classified as moderate-to-vigorous physical activity (MVPA), which doctors recommend for disease prevention.
- Over time, this translated to an extra hour of MVPA per week, nearly doubling the likelihood of meeting recommended physical activity guidelines (150 minutes per week).
- The effect was symmetric and environment-driven: moving to less walkable areas reduced activity, while moving between similarly walkable places produced no change. This finding builds on an earlier 2017 Nature paper that first revealed global “activity inequality” through smartphone data. That study showed large differences in daily steps across cities and countries, but couldn’t prove cause and effect. The new research answers that big question: the environment drives behaviour.
The Global Opportunity
The implications go far beyond individual health. The UN Secretary-General has noted that around three-quarters of the infrastructure needed for 2050 has not yet been built. While this is not a direct UN statement, it reflects a widely recognised reality: the world faces a massive infrastructure gap.
This means that we still have a historic opportunity to design future cities intentionally—with walkability, sustainability, and public health at their core. Aligning with the UN Sustainable Development Goals, particularly SDG 3 (Good Health and Wellbeing) and SDG 11 (Sustainable Cities and Communities), the evidence is clear: investing in sidewalks, parks, and mixed-use developments is not just urban planning—it is population health strategy.
WHIS Cities: From Evidence to Action
At the World Health Innovation Summit (WHIS), we believe health is created in homes, workplaces, schools, and crucially, in the streets and public spaces of our communities. Our WHIS Cities programme is designed to help leaders, innovators, and communities turn this type of evidence into action.
- Prevention by Design – Walkable cities embed healthy behaviours into daily life, reducing the burden of chronic disease.
- Equity in Health – Because the environment drives outcomes across all groups, improving walkability helps tackle health inequalities.
- Community Wellbeing – Safer, greener, and more connected neighbourhoods strengthen social bonds and resilience.
- Economic Growth – Healthier, more active populations are also more productive, while walkable areas support thriving local economies.
A Word from WHIS Leadership
“This Nature study is a vivid demonstration that our built environment is more than backdrop, it is a health determinant. When people move to more walkable cities, their health improves almost immediately. Coupling that with the UN’s insight that three-quarters of our future infrastructure is still to come, we see an extraordinary opportunity. WHIS Cities will be that bridge, ensuring our next wave of urban development builds wellbeing from the ground up.” — Gareth Presch, CEO, World Health Innovation Summit
References
- Althoff, T., Ivanovic, B., Hicks, J. L., Delp, S. L., King, A. C., & Leskovec, J. (2025). Causal evidence that walkability affects physical activity. Nature. https://doi.org/10.1038/s41586-025-09321-3
- Althoff, T., Sosic, R., Hicks, J. L., King, A. C., Delp, S. L., & Leskovec, J. (2017). Large-scale physical activity data reveal worldwide activity inequality. Nature. https://doi.org/10.1038/nature23018
- United Nations (2024). Secretary-General statements on infrastructure and sustainable development. UN Sustainable Development Goals.