To test their hypothesis, researchers compared the density of living areas with the body mass index (BMI) of more than 400,000 British citizens. The result: the ideal population density for maximum health benefits is around 3,200 residents per km2 (The Lancet).
That number corresponds to the typical urban areas in Europe, where the population density of the average city varies between 3,000 and 6,000 residents per km2 – compared with an average of around 10,000 residents per km2 in Asia, and 1,000 to 2,500 residents per km2 in North America and Australia (Future Cities & Environment). What is the secret of these cities? Compact urbanism that encourages walking, physical activity and social interaction, while providing ample infrastructure and local retail. Less densely populated cities and suburbs are also less connected, which promotes a sedentary lifestyle and a reliance on cars.
Since the 1960s, many studies have explored the connection between cities and health, even giving rise to specialties like urban sociology and social psychiatry (WHO). This field of research seems to have benefited from renewed interest in recent years, with studies analyzing the link between cardiovascular disease and urbanism (Heart Fondation) and science publications assessing the impact of city life on mental health (NCBI). Urban environments have attracted so much attention because their population is projected to grow exponentially over the next decades (Unicef). That is why many countries have decided to grapple with these questions now, in order to support the demographic growth of cities and help them create a “sustainable” living environment (Next City).