The Geography of Obesity

Obesity has reached epidemic proportions in America. More than 72 million American adults are obese, according to estimates from the National Center for Health Statistics. But obesity varies greatly by state. The map below, from the Centers from Disease Control (CDC), shows the obesity rate for the 50 states, measured as the share of people with a Body Mass Index (BMI) over 30 which the CDC classifies as "obese."

A week or so ago, I looked at the relationship between smoking and a variety of economic, social, and health factors. With a helpful analytical hand from Charlotta Mellander, we found that smoking was significantly correlated with obesity as well as being correlated with education levels, class structure, and other factors. So, we decided to take a quick look at the state-level factors that might be associated with obesity. We ran some simple correlations and scatter-plots between state obesity rates and these factors. As usual, we point out that correlation does not imply causality, but simply points to associations between variables. Still, a number of interesting things stand out.

It should come as little surprise that states with higher levels of obesity have significantly higher rates of death from cancer, heart disease, and cerebrovascular diseases like hypertension. There is a significant correlation between obesity and death rates from cancer (.7), heart disease (.7), and cerebrovascular disease (.7).

It might be, however, that states with greater percentages of obesity are those where people pay less attention to their health generally or are more likely to engage in risky behavior. And that's what we find at least in the case of smoking which correlates highly with state levels of obesity (.8).

Might obesity be related to states' broader social and psychological climates? To get at this, we looked at the relationship between obesity and a commonly used measure of subjective well-being or happiness developed by the Gallup Organization. Obesity is negatively associated with state happiness (with a correlation of -.6). Since these correlations only reflect associations between variables and not causality, it's hard to say whether this reflects the fact that happier people eat less, are healthier, or are less prone to obesity, or if unhappier people eat more, are unhealthier, or are somehow more prone to obesity, or if both obesity and happiness levels reflect something else. To get at this, we look at the associations between state obesity rates and social and demographic factors below.

Common sense would suggest that more affluent people would have lower levels of obesity and poorer ones higher, and we find such an association. Obesity is correlated with income levels (-.6) and more moderately so with economic output, measured as gross state product per capita (-.4).

One would think that states with greater concentrations of more highly educated people have lower levels of obesity, and that is what we find. States with higher levels of human capital, measured as the percentage of adults with a college degree, have lower levels of obesity (the correlation being -.8).

To what extent does obesity reflect the kind of work people do? We examine the relationships between obesity and three classes of jobs - creative/professional/knowledge jobs, blue-collar working class jobs, and standardized service class jobs like those in food processing and home health care. Obesity is strongly associated with the share of working class jobs (with a correlation of .7). Obesity is negatively correlated with the share of creative class jobs (-.6). Obesity is also negatively correlated with the share of service class jobs (-.4), though more moderately so.

Obesity is lower in states with higher concentrations of artists, musicians, and entertainers (with a correlation of-.6), those with larger concentrations of gays and lesbians (-.5), and immigrants (-.5). This likely reflects broader structural characteristics of those states, as more highly educated states also tend to be more tolerant and open to diversity.