It is time to show our cards.
I'm an urbanist currently specialized in health and environmental problems. I'm not a physician, but I work with them on a daily basis.
In Africa, we were focused on sanitation and diseases related to bad water quality. But in Europe and the US, we mainly focus on pollution, avalaibility of health structures, cleaning and recycling various wastes, but also on the obesity epidemy.
Obesity has become the major health issue in developed countries, and is indirectly responsible for millions of deaths. So we work on how to make our built, political, cultural and physical environment less likely to promote obesity. And every physician or major health institute I've worked with, recommended the same thing: 1/ Make people exercise and walk more, and 2/ Educate people more about nutrition, make healthy products avalaible for them.
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I'm not here to make fun of obese people. On the contrary, my current job (this year) is to help them to find a cure. But we can do nothing if obese people don't acknowledge it's a disease, if they do not have the will to cooperate. And it's not because obesity has now become commonplace that it makes this disease less deadly. It is a deadly disease, a disease mostly due to our current way of living.
For most cases we've studied, obesity works like an addiction to eating (especially sugar). People simply eat too much on average, and very unhealthy products. And you have to treat most obese people like people addicted to alcohol, tobacco or an heavy drug. They will behave the same way, most of them will be in complete denial of their situation, blaming genetics or inherited factors, or the so-called "slow metabolism" (no medical study has ever proven such a "slow metabolism" clearly existed). In fact most medical studies show that obese people frequently minimise the real amount of food they eat, that they hide it, exactly like an alcoholic person would do.
And they need to exercise more frequently. I do not mean playing sports or suffer like a marathonian, but just walking a few miles each day. It's not a big deal, really, but it can have a tremendous effect on your health, more than if you play sports (even very intensively) only during the week ends..
And that's where the physical environment, the structure of the city is important. Because if you're forced to use your car everyday, whether because you need it to go to work or to buy your daily stuff, you won't walk a lot. So the worst possible environment (from our perspective), is the extensive disconnected suburb with single housing and cul de sac, where a lot of space is wasted (urban sprawl).
Obesity is correlated by multiple factors, but is more prevalent:
1/ If you have a low level of education.
2/ If you use your car everyday instead of walking, biking or taking public transports.
3/ If you do not have access to varied commerces and services in your immediate vicinity -low mixed land use- (you should boycott the malls and especially discount stores).
And this rule applies in every major metropolis in the world, regardless of continent or culture. So this has led to the twin concepts of walkability and active design. Built environments are now rated on how walkable they are, how they induce a pleasant walking activity.