Does poverty make people obese, or is it the other way around?

The state of the universe.
Sept. 28 2009 2:47 PM

Give Me Your Tired, Your Poor, Your Big Fat Asses …

Does poverty make people obese, or is it the other way around?

Read more of Daniel Engber's columns on obesity and health care reform.

Illustration by Mark Alan Stamaty. Click image to expand.

In my last column ("Let Them Drink Water!"), I suggested that a tax on sweetened soft drinks would move the nation toward an apartheid of pleasure in which the poor must drink from the faucet while the rich enjoy superpremium fruit juice. I also argued that the soda tax discriminates on economic grounds, since rates of soft drink consumption tend to be highest in poor, nonwhite communities. But supporters of the measure counter that these very communities would benefit most from drinking less soda and that revenue from a regressive fat tax could be spent on laudable progressive goals—like universal health care.

Daniel Engber Daniel Engber

Daniel Engber is a columnist for Slate

The relationship between poverty and obesity keeps turning up in the debate over health care reform. Among the 46 million people in America who lack medical insurance, about two-thirds earn less than twice the poverty level (PDF). Advocates for universal coverage say that we can pay for all these new patients by cutting back on obesity rates, since excess fat accounts for 9 percent of the country's spending on medical care.   (During the campaign, then-Sen. Obama claimed this might save the Medicare system $1 trillion.) Some even suggest that a reform package should include special taxes or higher premiums for fat people. That idea starts to seem misguided, though, when you consider that poverty and obesity tend to overlap in some complicated ways.

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As a matter of public health, it might be more important to help poor people than fat people. According to epidemiologist Peter Muennig, the relative risk of mortality for being obese is between 1 and 2. That means that, controlling for other factors, someone who's really fat is up to twice as likely to die early as someone whose body mass index is in the normal range. But if you compare people from the top and bottom of the wage scale (with everything else held constant), the risk ratio goes up to about 3.5. In other words, it's much better for your health to be rich and fat than poor and thin.

Those in greatest need, furthermore, tend to be both poor and fat. We know, for instance, that the lower your income, the more likely you are to inhabit an "obesogenic" environment. Food options in poor neighborhoods are severely limited: It's a lot easier to find quarter waters and pork rinds on the corner than fresh fruit and vegetables. Low-income workers may also have less time to cook their own meals, less money to join sports clubs, and less opportunity to exercise outdoors.

If poverty can be fattening, so, too, can fat be impoverishing. Paul Ernsberger, a professor of nutrition at Case Western Reserve University, lays out this argument in an essay from The Fat Studies Reader, due out in November. Women who are two standard deviations overweight (that's 64 pounds above normal) make 9 percent less money (PDF), which equates to having 1.5 fewer years of education or three fewer years of work experience. Obese women are also half as likely to attend college as their peers (PDF) and 20 percent less likely to get married. (Marriage seems to help alleviate poverty.)

When it comes to public health, the relationship between poverty and obesity gets more convoluted. Being fat can make you poor, and being poor can make you sick, which means that being fat can make you sick irrespective of any weight-related diseases. Fatness (or the lifestyle associated with obesity) also creates its own health problems, regardless of how much money you have—and health problems tend to make people poor, through hospital bills and missed days of work. So fat can be impoverishing irrespective of any weight-related discrimination.

The point here is that sickness, poverty, and obesity are spun together in a dense web of reciprocal causality. Anyone who's fat is more likely to be poor and sick. Anyone who's poor is more likely to be fat and sick.  And anyone who's sick is more likely to be poor and fat.

Sociologists describe these patterns in terms of social gradients. The "health-wealth gradient" refers to the fact that, as a general rule, the richer you are, the healthier you are. This applies across different countries and across the full range of social classes within the same country. (It's not just that the very poorest people are sick.) No one knows exactly what causes the health-wealth gradient or why it's so resilient. It may be that rich people have access to better health care. Or, as we've seen, it could be that being sick costs you money. Then there's the possibility that poor people have a greater incentive to behave in unhealthy ways: Since they don't have as much money to spend on happiness, they "spend" their health instead. (The pleasures of smoking and eating, for example, are easy on the wallet and hard on the body.)

Related to the health-wealth gradient is what we might call the "girth-wealth" gradient. In 1989, a pair of researchers named Albert Stunkard and Jeffery Sobal pored over several decades' worth of data on obesity rates and concluded that socioeconomic status and body size were inversely related among women in developed countries. A recent review by Lindsay McLaren found that the pattern of poor women being fatter than rich ones has begun to spread into the developing world. (For men, the girth-wealth gradient tends to go in the opposite direction, and the health effects of obesity are somewhat diminished.)

Both gradients appear to be deeply entrenched in modern life, and we shouldn't count on universal health coverage to erase either one. International surveys suggest that the development of free medical care—through the National Health Service in the United Kingdom, for example—doesn't much alter the fundamental relationship between health and wealth. It's also not clear that expanded health coverage is likely to make the poor any less fat. A study published over the summer even suggests that the opposite might be true—a public option could end up increasing obesity rates among the newly insured.

The mere existence of these gradients does suggest that if we spread around the wealth a little better, poor people would end up healthier—and thinner—than they were before. According to British economists Richard Wilkinson and Kate Pickett, this benefit wouldn't necessarily come at the expense of the rich. Their new book, The Spirit Level: Why Greater Equality Makes Societies Stronger, uses data from the World Bank, the World Health Organization, and the U.S. Census to argue that disparities in income produce a wide range of social ills—like obesity, teen pregnancy, mental illness, murder, and infant mortality—that could be addressed by shrinking the gap between the haves and the have-nots. Indeed, the United Kingdom's Labor government has taken up this charge in recent years, with a series of measures to reduce inequality in the name of public health

The United States could try to do the same, by raising the minimum wage or increasing earned-income tax credits. In 2001, Princeton economist Angus Deaton considered the implications of a Robin Hood health policy. (His thoughtful and accessible paper on the topic is well worth reading.) Deaton concluded that a direct redistribution of wealth might be an efficient way to improve the health of the poorest Americans. But he warned that equality shouldn't be treated as an end in itself. A fancy new treatment, for example, might steepen the health-wealth gradient when it's first introduced, since only the rich can afford it. But that doesn't mean we should avoid medical breakthroughs for the sake of public health. According to Deaton, a saner approach would be to invest in education, since better schooling seems to improve your health and raise your income, too.  

You don't hear anyone suggesting that better schools could pay for health care reform, though. Instead, we've pegged our hopes on a national weight-loss regime—a redistribution of girth instead of wealth. If being poor can make you fat and vice versa, then we can't solve one health problem while ignoring the other. Yet we act as though the war on obesity can be separated out from the war on poverty: Consider the soda tax—an anti-obesity measure that shifts money away from the poor.

Why are we so fixated on body size? Another social gradient might be playing out in this policy debate: It turns out that the richer you are, the more likely you are to be on a diet. (Among fat people, more wealth correlates with lower self-esteem.) So it's only natural that we'd be hung up on the issue of obesity—we're projecting. In my next column, I'll look at how this tendency might itself be a risk to public health.

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