Neighbourhoods that enable physical activity and offer access to healthy foods appear to impact residents' weight.

Neighbourhoods "influence the extent to which people adopt and maintain behaviors linked to obesity," Dr Mahasin S. Mujahid of Harvard University's School of Public Health in Boston, Massachusetts told Reuters Health.

"Even highly motivated individuals will find it very difficult to be more physically active and eat healthy foods if they live in environments that do not help support these lifestyles," said Mujahid.

Mujahid and colleagues looked at associations between the physical and social aspects of neighbourhoods in New York City, Baltimore, Maryland, and Forsyth County, North Carolina and the body weight of 2,865 adults who lived in these locations between 2000 and 2002.

The average age of the participants was 62 and roughly half were women. More than 45 per cent had lived in their respective neighbourhoods for at least 20 years, the investigators report in the American Journal of Epidemiology

The researchers found that men and women living in neighbourhoods with better walking environments and availability of healthy foods were leaner than those living in less physically desirable neighbourhoods.

Neighbourhoods rated higher in social qualities, such as safety, aesthetics, and social cohesion, were associated with lower overall body mass index among women. However men showed the opposite - higher body mass index among those residing in highly rated social neighbourhoods - and the investigators say further research must confirm this unexpected finding.

Overall, Mujahid notes, these findings add to a growing body of evidence that indicates genes and individual choice, as well as the environments in which people live affect health. Continuing research needs to further assess links between environment and obesity, Mujahid and colleagues conclude.

SOURCE: American Journal of Epidemiology, June 2008