For the haters, I link you to this study from the OECD (there are thousands of studies, but this one is pretty recent). You’ll see that, among developed nations, that there is a large correlation between years of education and BMI. This factor is amplified among women (for example, there is a difference of 4 BMI points between those with 8 years of education and those with 18 in England). These women are representative of their cohorts; educated men and women are, in general, fitter than their less-educated peers. To what degree this is causal is up for debate, but the correlation remains.