Obesity, Food Deserts, and a Paradox

Robin Hanson had a post citing research that there was no relationship between poverty and obesity.  That surprised me.

This CDC report shows a strong relationship between ethnicity and obesity--blacks and Hispanics tend to be more obese than whites.

Between 1988-1994 and 2007-2008 the prevalence of obesity increased (Figure 2):

• From 11.6% to 16.7% among non-Hispanic white boys.

• From 10.7% to 19.8% among non-Hispanic black boys.

• From 14.1% to 26.8% among Mexican-American boys.

And a search for "obesity, income" on CDC comes up with this:

• Among men, obesity prevalence is generally similar at all income levels, however, among non-Hispanic black and Mexican-American men those with higher income are more likely to be obese than those with low income.
• Higher income women are less likely to be obese than low income women, but most obese women are not low income.
• There is no significant trend between obesity and education among men. Among women, however, there is a trend, those with college degrees are less likely to be obese compared with less educated women.
• Between 1988–1994 and 2007–2008 the prevalence of obesity increased in adults at all income and education levels.

 and

Among men, obesity prevalence is generally similar at all income levels, with a tendency to be slightly higher at higher income levels.

The Paradox Identified

So Hanson looks to be partially right, at least with regards to the U.S. And I didn't get into the research to know how well it distinguishes among the variables: ethnicity versus income.  But what's interesting to me is the difference between men and women, particularly for blacks and Mexican-Americans.  Why are rich black men thin and poor black women fat (using oversimple language to make the point) and vice versa? That doesn't seem to me to support the concept of "food deserts". Indeed, it seems to confound any general theory:  genetics, income, environment, etc.