Academics have long been exploring the relationship between neighbourhood characteristics and obesity. There are many variables to either examine or control for, including physical layout of the built environment (suburban, rural, urban, and the myriad sub/cross-categories), socioeconomic status, availability of healthy and affordable food, etc. Depending on what you measure and which statistics you employ, you could probably make the needle swing any way you'd like. However, there are established links between daily hours spent in a car and obesity, and likewise between neighbourhood design/location and hours spent in a car. So we can reasonably suggest that if your neighbourhood forces you to spend more time driving and less time using active transportation, then you are more likely to struggle with obesity.*
OK, academic tip-toeing aside - time to make this real. Consider this passage from Shaping Neighbourhoods:**
The importance of neighbourhood design is highlighted by the fact that, for most obese adults, weight gain has been accumulated over a number of years. A small daily or weekly imbalance in this energy account [intake vs. expenditure] over a decade can lead to major weight gain. The Institute for European Environmental Policy has calculated that the decline in walking itself is enough to account for much, if not all, of the recently observed upsurge in obesity. [...]
- Each additional hour a day spent in a car is associated with a 6% increase in the likelihood of obesity. Each additional kilometre walked a day (12 minutes) is associated with a 4.8% reduction in the likelihood of obesity (Frank et al, 2004).
I find this both bleak and exciting. The sad-face arrives when I think of all the layers stacked against walking in the suburban neighbourhood where I grew up and where my parents still live. There's the distance - just a little too far to carry a litre of milk and bag of apples home let alone groceries for a whole family. There's the noise of 60 km/hr x4 lanes, drowning out pleasant thoughts or conversation and passing uncomfortably close to the sidewalk. There's the general ugliness of it all - asphalt by the acre protecting architecturally vacant blah. There's the fact that there isn't really anywhere worth going within walking distance unless you loooove chain store shopping or unhealthy food. To put it lightly, the cards are stacked in favour of driving and when every day of your life you have to stare down that imbalance or else put on gram after gram of unused energy... that's tough.
On the other hand, the solutions to this - active lifestyles (not just an hour of gym time you tack on the end of your day) and healthy food - are beautiful. Is this not what we want anyway and were somehow cheated out of? Put it that way and cutting down population level obesity sounds like a really nice vacation not a strenuous and miserable slog on the treadmill.
Another fine quote:
To tackle population level obesity, whilst taking into account health inequalities and promotion of communties, the first urban agenda is to build activity back into every day lifestyles and movement patterns. The promotion of gyms and organized sports may be effective for some individuals, in some socioeconomic groups, for a limited period of time, but as a response to population level obesity, is not an adequate or effective strategy. The second urban agenda must be to ensure access to good quality fresh food including food growing opportunities at the local level (Barton et al, 2003).
When I read this, I think of my mom. She's an athletic lady who grew up working on the farm and playing sports. Even today, she walks my dog when he starts pawing at her face at 6 am and bikes to work despite the environment I depicted above. My mom does not want to buy a gym membership or run like a maniac five times a week and she shouldn't have to, especially as she is aging gracefully into a beautiful grandma (newly minted, not my doing). She's a naturally active person so it just makes way more sense to build activity in the fabric of life. That said, where would you rather walk and get healthy food?
More on this discussion later, especially the bit about Boomers like my mom.
Until then, thanks for reading!
- - -
*There are dozens of published studies on this topic, but Frank (2004) does a great job summarizing the findings and points to many other references. Still, remember that transportation is not the only potential source of physical activity. Recreational exercise can obviously offset an imbalance in energy intake vs. expenditure. In fact, Rodriguez et al. (2006) studied the differential physical activity levels in a conventional car-dependent suburb with a neighbourhood designed to increase walkability. They found that while the walkable neighbourhood walloped the conventional suburb in terms of walking and cycling trips per week within the neighbourhood, these were almost exclusively in utilitarian travel. Recreational activity remained much the same and so physical activity between the two settings was not statistically significantly different. Just one study in a sea of many offering varying accounts...
Frank, L.D. (2004) Economic determinants of urban form: Resulting trade-offs between active and sedentary forms of travel. American Journal of Preventive Medicine, 27(3),146–153.
Rodríguez, D.A., Khattak, A.J., & Evenson, K.R. (2006). Can New Urbanism encourage physical activity? Journal or the American Planning Association, 73(1), 43-54.
Barton, H., Grant, M. and Guise, R. (2003) Shaping Neighbourhoods: A Guide for Health, Sustainability and Vitality, Spon Press: London, p.18.
Frank, L.D., Andresen, M., Schmid, T. (2004). Obesity relationships with community design, physical activity, and time spent in cars. American Journal of Preventative Medicine, 27(2), 87–96.