Nobody’s going to deny that there’s a role for personal responsibility in the obesity issue. And likewise, nobody’s going to deny that genetics also play a role – gaining weight is far easier for some people than others. The problem with discussions about obesity is that they tend to be dominated by these two positions. And then, of course, it becomes a question of blaming people for their own health problems.

Niether of these explanations, though, could really explain the massive rise in obesity in the last few decades. The Canadian obesity rate nearly doubled between the end of the 1970s and this decade. And most other first world countries have seen similar increases – most dramatically in nations like Japan which have embraced a more American-style culture.

Consider the genetics “answer” – did skinny people stop breeding? Or did some great big guy have fun with everyone’s wife? Perhaps some sort of mutation caused by GMO foods? Or perhaps people all just became dramatically less responsible for themselves during that time?

A much better answer would be cultural – changing habits, diets, and food systems. As I’ve mentioned before – the amount of nutrition in our food has been falling for years. And that means for every daily dose of iron, calcium or B-vitamins, we must eat more calories (fats, sugars and starches), as well as preservatives/flavourings like salt or MSG. Not only does this lead to obesity, but a host of other diseases generated by unhealthy foods like heart disease and high blood pressure. Many others avoid those completely by cutting calories and salt, but then lack essential nutrients (linked to everything from depression to cancer). Not everyone is affected the same way – all of our bodies, diets and lifestyles are different. But you don’t see a side-by-side explosion of obesity and malnutrition without something going drastically wrong with your society’s source of food.

Of course physical activity is also part of the answer. As a society, we (and by that I mean our leaders) have embraced methods of work, transportation, and play, which burn very few calories and build very few muscles. Kids spend half as much time outside as they used to, with many serious documented physical and mental problems associated. We spend far more time in car than we used to – a recent advertising study showed that Americans spend an average of over two hours per day in their cars(~14% of waking hours), and that the average commute has grown longer in every single market they studied.

All the “personal responsibility” and genetics in the world won’t help us cope with a world where food itself is getting much less healthy, and in which opportunities for exercise are vanishing everywhere.

For a more in-depth and colourful look at these issues, check out The Weight of the World, a facinating NFB Documentary about obesity and the social issues surrounding it.