Poor people have higher rates of obesity. There are those who believe that's because the poor lack self-control and discipline, overeating when they should be pulling themselves up by their bootstraps. That hard-core personal responsibility ethic is hard to refute, maybe because it contains a grain of truth, maybe because it lets all us non-poor people off the hook. It's an issue where opinion and personal politics have ruled, because proving that cultural or environmental factors directly influence obesity seems almost impossible. But as Ludwig et al report, it looks as if that's exactly what the supposedly feckless U.S. Department of Housing and Urban Development has done.
Between 1994 and 1998, HUD randomly assigned 4498 women with children living in public housing in high-poverty urban census tracts (in which ≥40% of residents had incomes below the federal poverty threshold) to one of three groups:
- 1788 were assigned to receive housing vouchers, redeemable if they moved to a low-poverty area (where <10% of residents were poor), and advice on moving;
- 1312 received unrestricted traditional vouchers (not requiring moving to a low-poverty area), and no moving advice;
- 1398 were assigned to a control group (no voucher and no counseling).
They were then measured and surveyed on health outcomes from 2008-2010.
Those who moved to a low-poverty area had an absolute 4.6% lower rate of severe obesity (BMI 35+), 3.38% lower rate of BMI 40+, and lower rates of diabetes (hemoglobin A1c > 6.5%) an absolute 4.3% lower, compared to the control group. There were no differences in the rates of these outcomes between the group getting traditional vouchers and those getting no vouchers.
Of course everyone must take personal responsibility for her own health. But remember this article in NEJM in 2007? Obesity appears to be contagious between family, friends and neighbors. Poor people have reduced access to good food and safe exercise opportunities, and higher levels of chronic stress. Think we're each the master of our destinies and waistlines, and environmental influences don't matter? Fat chance!
(I'm not touching the political and ethical implications of randomizing poor people to life- and health-changing interventions as part of these social experiments, which sound uncomfortably like something out of Krushchev or Mao's playbook.)
Ludwig J et al. Neighborhoods, Obesity, and Diabetes — A Randomized Social Experiment. N Engl J Med 2011;365:1509-1519.