Effective City Planning Promotes Health

Older, more compact cities promote more walking and biking and are generally healthier than many newer cities. Wesley Marshall, from the University of Colorado (Colorado, USA), and colleagues analyzed 24 medium-sized California (USA) cities with populations between 30,000 and just over 100,000 residents.  The researchers examined street network density, connectivity and configuration, factoring these measures as to their impact on rates of obesity, diabetes, high blood pressure, heart disease and asthma. Analysis revealed that increased intersection density was significantly linked to reduction in obesity at the neighborhood level and of obesity, diabetes, high blood pressure, and heart disease at the city level. The more intersections, the lower the disease rates. The study also found a correlation between wider streets with more lanes and increased obesity and diabetes rates, as wider streets may be indicative of an inferior pedestrian environment. The study also considered the `food environment’ of cities. Cities with more fast food restaurants were associated with higher diabetes rates while additional convenience-type stores across a city correlated with higher rates of obesity and diabetes. Overall, the study showed that the healthiest cities had shorter blocks and more intersections. Separately, a study by London School of Hygiene and Tropical Medicine and University College London (United Kingdom) researchers reveals that people who walk, bike or take public transportation to work tend to be thinner than those who ride in their own cars. Ellen Flint and colleagues analyzed data collected from a national sample of people living in the UK, involving 7,424 people and how much body fat they had and from 7,534 on their body mass index (BMI). After adjusting for traits or behaviors that may influence weight or body fat, such as socioeconomic status and other exercise, the researchers found that people who walked, biked or took public transportation to work had lower average BMIs and body fat percentages than people who used private transportation.