The Obesity Epidemic

Obesity is bad for public health, bad for the environment. What can be done?

[There was a technical problem with the version of this posted earlier.]

Obesity is an issue that gets sporadic media attention. But it’s a serious problem, and it’s getting worse. An ever-increasing proportion of the population suffers from obesity. If present trends continue, over half the U.S. population will be obese in another twenty years or so. This trend is especially troubling because individual obesity is difficult to reverse.

There is no easy answer to this problem, but we are making some progress in identifying useful policy responses. I’ll start by explaining why the problem is so important, then discuss trends and possible policies, and end with a look at the path forward.

The harmful effects of obesity. Obesity can have serious consequences. As Harvard economist Kenneth Rogoff writes:

“Although it is difficult to gauge the long-run health consequences, there is abundant evidence that obesity contributes significantly to higher rates of type II diabetes, heart attacks, and certain types of cancer. The health costs are staggering, estimated to be close to $200 billion per year in the US alone. And with rising childhood obesity rates worldwide portending significantly greater health problems in the future adult population, the costs are likely to rise considerably.”

There are also environmental consequences. An increasingly obese populations puts more demand on food resources, increasing the environmental footprint of American farmers. The increased pressure on food prices may also encourage conversion of forests or grasslands to agriculture use, not just in the U.S. but elsewhere in the world since grains and soybeans are a global market. And the obese are likely to need larger vehicles, increasing gasoline use.

It’s worth taking a closer look, then, to see what we know about the obesity growing and how to control it.

Obesity’s upward trend. Let’s start with a closer look at the trend. Here some of the relevant numbers from an article in Forbes, based on new CDC findings:

“[N]early 4 in 10 U.S. adults have a body mass index classifying them as obese. Adult obesity rates have continued to increase steadily since the turn of the century, rising from 30.5 percent in 1999-2000 to 39.6 percent in 2015-2016, a record high. Young Americans have also been piling on the pounds and the obesity rate among the country’s youth (aged 2-19 years old) currently stands at 18.5 percent.”

In case you’re wondering, the CDC defines obesity as a body mass index over 30. That’s not an intuitive definition for most of us, so an example may be helpful. For someone who is 5’9”, that means a weight over 200 pounds.

Who and where? Obesity rates vary by states. The states with the most obesity are West Virginia and Mississippi (at 37%); the ones with the least are Colorado, Hawaii, and Massachusetts (at about 22%). Whatever factors produce obesity correlate with those that produced Trump voters: all of the top 17 voted for Trump, but only four of the bottom 17. Most states have roughly the same upward trend as the national average: low obesity states started low and have stayed at the bottom despite more or less following the national trend. California is an odd exception – it was more or less in the middle of the pack until around the turn of the century, but the obesity rate seems to have more or less stabilized since then.

In terms of other demographic factors, obesity rates in whites are somewhat lower than among Hispanics and blacks, but Asians have a much lower rate than any of these groups. People who live in large urban areas are substantially less likely to be obese than other groups, with the highest rate being among rural populations. There are some oddities, however, as the Atlantic observed a few years ago:

“Poorer women are the most likely to be obese among all ethnicities. But there are a few counter-intuitive surprises here. The richest men were, overall, more likely to be obese than the poorest groups. The groups with the lowest rates of obesity were rich white women and poor black men. Obesity rises with income for black and Hispanic men, but it falls with income for black and Hispanic women.”

Thus, as the Atlantic said, the “relationship is clearly more complicated than “a disease for poor people in a rich country.”

There’s also some recent research suggesting that obesity is “contagious” in the sense that being around obese people increases the odds that an individual will become obese. This may create a snowball effect that can be difficult to combat.

Policy interventions. As I mentioned before, California’s obesity rates seem have stabilized. This is also true for childhood obesity. California also has a lot of policies aimed at promoting exercise and better eating habits, but it’s not necessarily clear which are effective – or indeed, whether something unusual is happening in California unrelated to policy. Childhood obesity rates have leveled off nationally more recently, which will help reduce future adult obesity rates. A CDC report concluded five years ago that “little is known about policy approaches that are most effective,” at least in terms of rigorous empirical evidence. One priority is more empirical research to find out what works and what doesn’t.

In the meantime, as Rogoff says, “a growing body of evidence suggests that a culture emphasizing processed food and a generally sedentary lifestyle lies at the center of the problem.” To address the problem, he recommends improved nutritional education, regulation of food advertising to children, and a tax on processed foods. In a similar vein, my colleague Steve Sugarman has proposed an incentive scheme that rewards soft drink companies or decreasing in obesity in a community’s schools.

Attempts to address the issue of sedentary lifestyles may also be promising; one reason that people in cities tend to be less obese may be that they end up walking more. There’s some evidence that increases in mass transit can help reduce obesity. A 2017 study in Preventive Medicine indicates that “a one percent increase in county population usage of public transit is associated with a 0.221 percent decrease in county population obesity prevalence at the α = 0.01 statistical significance level.”

What next? We can’t expect the Trump Administration to take action on the obesity problem. Rather, the Administration is already trying to rollback the federal government’s efforts to improve nutrition. In April, the FDA delayed rules requiring calorie counts on restaurant menus. A week later, the Ag Department loosened nutritional rules for school lunches. In June, the Administration indefinitely delayed food labels that would have provided more information about sugar and calorie counts. Also, Trump’s budget proposal for 2018 cuts mass transit funding by half, while the House’s proposed cut is almost 30%.

Obesity is another area like climate change, then, where states and cities are going to have to take the initiative. There’s no reason for this to be a partisan issue. Back when he was governor of Arkansas, Mike Huckabee embarked on an anti-obesity crusade. The Times summarized his initiatives back then:

“Many of his policies include incentives like exercise breaks for state employees. He has expanded state insurance coverage to cover obesity treatment. He advocated restricting access to vending machines for high school students and replacing the sugary sodas in them with juice and water. Arkansas is one of a handful of states where the nutritional guidelines for school lunches are stricter than the federal requirements.”

If Mike Huckabee can do it, why not other Governors?

Climate Change, diet, public health