Built for health? New review explores How neighbourhoods influence obesity through physical activity
A new systematic review published in Obesity Reviews investigates how the design of neighbourhoods and cities influences obesity in adults—and whether physical activity acts as the key link in that relationship.
The study, led by researchers from the University of Canberra and RMIT University, synthesises evidence from 19 studies across 11 countries. It finds that features of the built environment—such as walkability, green space, and land use—are associated with adult obesity, and that physical activity often plays a mediating role, particularly when environments are designed to support walking or cycling.
While the review confirms that neighbourhood design can shape health outcomes, it also highlights the complex and context-specific nature of these relationships. For example, the same built environment features may have different effects depending on the density of a city or the socioeconomic profile of a population.
Key findings
- Walkability matters: The most consistent evidence of mediation came from studies examining walkability, where higher walkable neighbourhoods were linked to greater physical activity and lower levels of obesity—especially when activity was measured objectively.
- Transport-related movement is key: Walking or cycling for transport, rather than total physical activity, showed a stronger mediating effect. This suggests that built environments supporting everyday movement may be especially effective.
- Mixed results for green space: While green spaces are often cited as health-promoting, their impact on obesity via physical activity varied between countries and measurement methods. In China, for example, green space had little mediating impact, while in the US, it accounted for up to 32% of the relationship.
- Quality of evidence needs improvement: Most of the reviewed studies were cross-sectional and of low methodological quality. Only one was longitudinal, limiting the ability to draw firm conclusions about cause and effect.
Implications for urban planning and public health
The review reinforces the need for context-sensitive, evidence-informed urban planning that promotes physical activity as part of daily life. It also calls for:
- More longitudinal studies to assess causality
- Better measurement standards for physical activity and obesity
- Tailored strategies that align specific behaviours (like walking for transport) with relevant environment features (like street connectivity)
As countries and health systems continue to invest in upstream solutions for obesity prevention, this review highlights the urgent need for more consistent and transparent economic evidence that reflects the realities of scaling interventions in diverse settings. Ensuring evaluations are grounded in real-world complexity will help maximise impact and value for money.
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World Obesity publishes four scientific, peer-reviewed journals, each focusing on a different area of obesity research: systematic reviews, pediatrics, clinical treatment, and science and practice.
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