There’s currently a great discussion ongoing in the Digital Health Group on LinkedIn; What are the root causes of poor health (and inefficient healthcare system) in US comparing with other industrialized nations in spite of advancements in technology? started by Michael Kremliovsky. It’s certainly a complex issue and the participants in the discussion have offered a wealth of diverse views. I along with many others suggested that:
… factors like diet and exercise and physical activity, all of which influence the obesity rate would play a significant roles in the difference of health between the US and Europe …
Coincidentally I had started collecting data on health risk factors in the US vs EU for a data visualization/infographic project, focusing first on sugar consumption with the idea of exploring how sugar consumption has increased over the past several decades and tracking that to increased rates of obesity and Body Mass Index (BMI).
Since I’m in exploratory mode I limited the set of countries to the following: United States, Canada, United Kingdom, Germany, France, Italy, Spain, Netherlands, Switzerland, Sweden, Norway, Belgium, Austria, and Portugal. I recommend clicking on the links to view the full size, interactive versions to see the details better. With the interactive version you can hover your mouse over the graph elements to identify countries.
Sugar Consumption – 1961 – 2004
It’s obvious from this line graph that sugar consumption per person per day has has increased in all of the countries included in this data set, some more dramatically than others. Sweden’s and Norway’s sugar consumption has grown very little but sugar consumption in the US has increased dramatically, as has Canada’s. The US, UK, and Switzerland all started out at the same consumption rate in 1961 but the US rate has grown much more and the US far outpaces the pack in our addictive consumption of sugar.
Next, how does Body Mass Index track over time? (According to the CDC: Body Mass Index (BMI) is a number calculated from a person’s weight and height. BMI provides a reliable indicator of body fatness for most people and is used to screen for weight categories that may lead to health problems. A BMI greater than or equal to 30 is considered obese.)
Body Mass Index (BMI) 1980 – 2004
Not surprisingly, the graph shows that Body Mass Index for each country has increased fairly dramatically since 2008 (the range of data available for BMI was smaller than for sugar consumption), and once again, the US is leading the pack in that increase. Just looking at these two charts it would be easy to jump to the conclusion that the increased sugar consumption has led to the increase in BMI. But that would open us up to the frequent problem of mistaking correlation for causation.
Next, it would nice to be able to see the correlation of sugar consumption to BMI or obesity rate. (While at some point I’ll do an animated scatter plot of the correlation over the time period of available data, a single scatter plot of sugar consumption to obesity rate will have to suffice for now.)
Sugar Consumption to Obesity Rate Correlation 2008
Once again we see that the country with the highest sugar consumption has the highest obesity rate in 2008. But, anybody who understands basic linear regression will see that since the dots are widely scattered, that they don’t cluster around a single trend line, the correlation between the two variables of sugar consumption and obesity rate is not a very strong correlation (at least with this small dataset).
What the scatter plot quickly indicates to me is that there is wide range of sugar consumption and obesity in Western Europe. Switzerland has a high sugar consumption but the lowest obesity rate, similar to France who’s sugar consumption is much lower. So, clearly it’s not a simple case of being able to blame rising obesity rates solely on rising sugar consumption. There’s likely dozens or even hundreds of other variables at play including other dietary consideration and physical activity. The one thing that does seem certain about sugar consumption from these simple charts is that the US has a significant problem with sugar over-consumption.
Sugar Consumption: Gapminder Foundation
BMI: Gapminder Foundation
Obesity by Country: World Health Organization