Freakonomics: on the obesity epidemic

August 22, 2007, 11:29 am

Freakonomics Quorum: What is the Right Way to Think About the Obesity ‘Epidemic’?

By Stephen J. Dubner

If you rely on nothing but the media for your information, you might think that obesity is the new Black Plague, laying to waste huge swaths of the population. But is it?

We’ve blogged more than a few times about the spike in American obesity. These posts have included: economists’ attempts to identify the causes of this spike; a post wondering if high gas prices might lead to skinnier Americans; and an attempt to generally get a grip on what obesity is and how much it matters.

With the public and media still fixated on obesity, I thought it might be worthwhile to take a step back and put an incredibly basic question to a variety of people who spend a lot of time thinking about the subject:

What is the right way to think about the American obesity “epidemic”?

This round of questioning has come to be known as a Freakonomics Quorum, with recent discussions on street charity and the housing market. Here are the participants for the discussion on obesity:

J. Eric Oliver, a professor of political science at the University of Chicago and author of Fat Politics: The Real Story behind America’s Obesity Epidemic; David Cutler, a former member of the National Economic Council who is now a professor of economics and a dean of social sciences at Harvard; Dr. Darwin Deen, a professor of family medicine at the Albert Einstein College of Medicine and co-author of Nutrition for Life and The Complete Guide to Nutrition in Primary Care; Dr. Lisa Hark, the director of the University of Pennsylvania School of Medicine’s Nutrition Education and Prevention Program, co-author of Nutrition for Life, and former host of TLC’s Honey We’re Killing the Kids; Matt Verbin, founder of the Obesity Forum, an encyclopedic online source of obesity studies and programs; and David Zinczenko, the editor-in-chief of Men’s Health magazine and author of the Abs Diet series.

J. Eric Oliver:

We hear a lot in the media these days about America’s obesity epidemic. A third of Americans, we are told, are “obese,” and two-thirds are “overweight.” Hundreds of thousands purportedly are dying each year from weighing too much, while countless others suffer from scores of “obesity related” diseases. Obesity has been blamed for everything from dragging down the economy to global warming. Most recently, we’ve heard that obesity is “contagious.”

The problem with these assertions is that they are based mostly on arbitrary definitions and fuzzy statistical conjectures. Although Americans have indeed grown heavier over the past three decades (the average American weighs about 8 to 12 pounds more than in 1980), it is not clear that this weight gain is putting them in any imminent danger. The primary reason so many Americans are “overweight” and “obese” is because these terms are defined at unjustifiably low levels of body mass. For example, under our current definitions, George Bush and Michael Jordan are overweight, while Arnold Schwarzenegger and Mel Gibson are obese. These standards were not based on any scientific evidence linking body mass to health, but were created by insurance actuaries and medical professionals with financial ties to the weight loss industry.

Similarly, the idea that obesity is itself a disease or causes disease is based largely on correlations in large epidemiological studies, not on any clear causal link between excess weight and disease. With the exception of a few minor conditions (like osteoarthritis), we don’t have any good evidence that adiposity causes any physical harm. By the same statistical criteria used to call obesity a disease, one could also claim that being male, being overly tall, or even being black is a disease (i.e., all correlate with early mortality and morbidity). The fact that we choose to demonize fatness rather than these other traits illustrates how concerns about obesity are rooted far more in political and cultural standards than scientific ones.

In short, the biggest problem with all the hype about the obesity epidemic is that it assumes that:

A) weight is a good barometer of health (it isn’t);
B) being thin is the same as being healthy (it’s not);
C) anyone can be thin if they want to (which is not true).

In the absence of any safe or effective weight-loss mechanisms, telling Americans they need to be thinner only encourages them to embrace unhealthy and unworkable diet plans. Arguably, prejudice and discrimination against fatness cause far more adverse health outcomes than the fat itself. Rather than worry about how fat our country is, we should be asking ourselves why we are so judgmental about how much other people weigh.

David Cutler:

As I write this in my office, a soda machine is not more than 20 steps away. Candy is practically within reach. In less than two minutes, I can walk to pizza, hamburgers, ice cream, muffins, bagels, cookies, and tacos (all in separate stores). Technology has brought us a wealth of good things; the computer on which I write this was undreamed of a generation ago. But easy access is one downside of progress. It takes all my energy not to eat chocolate continuously. And I love ice cream.

Some of us develop rules. I don’t drink caffeinated drinks — no obvious reason why, but that’s the rule. Chocolate is never eaten before lunch. I don’t get ice cream at work. Through these measures, I manage to keep my weight in check. But the rules are hard to keep. Technology is what allows us to be fat. The inability to discipline ourselves is why we let it happen.

The fascinating thing about progress is that it can be both good and bad. The discovery of nuclear fusion allows for cheaper, more environmentally friendly forms of energy. But it also allows for nuclear weapons. A generation ago, women spent an average of two hours per day cooking and cleaning; today, the cooking and cleaning is handled by a restaurant or food company. Weight gain is the consequence.

One of two measures will be needed to end the obesity epidemic. Technology might progress to where we can mass produce non-fat food as readily as fat food. Today’s cookies taste better than those of a few decades ago; apples are the same. Maybe a new kind of apple will be invented that has us rushing to the fruit store. Alternatively, we will have to discover the willpower to allow us to use technology only in moderation. I sometimes toy with a solution — maybe I should set aside $10 every week, which I get back at the end of the week if I don’t eat anything bad for me. We do this with saving (think Christmas clubs). Can widespread use of such a strategy for eating be far behind?

Or maybe progress will march along, and we will continue to get fat. In that case, we’ll develop and expand medical technology that treats the consequences of obesity — drugs for diabetes and high cholesterol; hip and knee replacements; new arthritis medications. All of those are expensive, but maybe the tradeoff for ice cream is worth it.

Dr. Darwin Deen:

An “epidemic” is defined by epidemiologists (who specialize in the health of populations), as a disease occurring at a greater frequency than expected. While the definition that we use for obesity has changed and our ability to measure body fat has become more sophisticated, there is no doubt that we are heavier than we were 20 or 30 years ago, and that this change will have the most dramatic health impact on our children.

It is alright to gain some weight as you get older (in fact, in middle age it is probably healthier to be overweight than to be thin), but people who are 50-100 pounds above the average weight for their height are at greater risk for diabetes, heart disease, and cancer. I am avoiding talking about BMI (body mass index) even though it is the way that physicians and researchers classify weight, as it is not that helpful when assessing an individual. What is more important for adults is belly fat.

The reasons for this increase in the number of people who are overweight are debatable, but one need only review the increases in typical portion sizes (I am 50 years old and still remember small glass Coke bottles and 3 oz. McDonald’s fries) to understand that we are eating more than we ever did. While exercise is an important part of staying healthy, the obesity epidemic has developed at a time when we have not started exercising any less (reductions in caloric expenditure — the calories that we burn through activity — are less now than they were 100 years ago, when everyone worked with their hands, but not less than they were 30 years ago, when the interstate and the office job were already the norm). So the right way to think about the obesity epidemic is that, in order to make sure you don’t suffer the medical consequences of obesity, you should eat a healthy diet (fruits, vegetables, whole grains, low fat dairy products), avoid “excess” calories (cakes, cookies, large portions, feeling “stuffed” except for occasionally), and get regular exercise.

If any of this is confusion to you, there are plenty of articles and books on the subject (I’ve written two myself); and, while most doctors have very little nutrition training, your doctor is absolutely the best person to tell you if your weight or lifestyle presents a hazard to your health.

Dr. Lisa Hark:

When I think about the obesity epidemic in America, I become very concerned with the current and future health of our entire society. America is known as the cradle of liberty, a place where people who work hard can succeed, make something of themselves, and live their dream life. But now, Americans are gaining worldwide notoriety for being the fattest country on Earth, home to more than 65 million overweight people. And it’s not just a cozy, “more of you to love” situation. Obesity and the conditions it causes — heart disease and diabetes, to name two — are responsible for almost 1 million deaths every year. And now our kids are experiencing the side effects. Rates of obesity in children are at an all-time high. For the first time in history, this generation of children is not expected to live longer than their parents. Rich, industrialized America is poised to experience a drop in life expectancy, all because we’re eating too much and we aren’t active enough.

So what’s the answer and the right way to think about obesity in America? My focus is on the family, and helping parents and kids. As parents, we need to step up and take responsibility for making sure our kids get the foundation that they need to lead healthy and active lives, now and in the future. Unfortunately, we have become a society obsessed with TV, and kids are learning this at a very young age. Experts now agree that screen time of all types needs to be limited for children and teenagers to less than two hours per day. I believe the less TV our kids watch, the healthier they will be. Studies show that the more children are exposed to TV ads for junk food and sweetened drinks, the more likely they are to consume large amounts of unhealthy food. We need to avoid putting TVs in our children’s bedrooms and start monitoring how much and what they are watching. This also includes computer and video game time. Children spend most of the school day sitting, so get them outside for some play time after school, and use weekends for active family bonding outings.

We also need to get back to basics and eat meals together as a family as many nights as we can. We must incorporate fruits and vegetables into all meals and snacks, offer water and low-fat milk instead of sweetened drinks, and get out and be active with our kids in fun and inviting ways. After school is a great time to get children to eat vegetables because they are so hungry. Try baby carrots, cut up cucumbers, peppers, tomatoes, or celery with low-fat ranch or French dressing. Offer fresh and canned fruit to satisfy cravings for desserts and sweets. Don’t rely on school lunch options. Pack a healthy lunch at least 3 times a week, along with a water bottle and fresh fruit.

Being healthy role models for our children is critical if we expect them to eat healthy and be active. And remember, it’s OK to say “no” to children when it comes to TV and unhealthy foods and drinks. If we aren’t firm in this area, advertising, peer pressure, and a plain old sweet tooth will override all of our good intentions.

Matt Verbin:

Obesity is a multi-faceted disease fueled by Americans’ poor eating habits, complacency and sedentary lifestyles. While the physical and emotional impact of obesity on a growing number of Americans is glaring, what truly makes obesity an epidemic is the economic impact it has on all of us.

People underestimate the economic effect obesity has on our society. The Center for Disease Control has concluded that illnesses associated with obesity cost the United States $93 billion a year in health care costs. Eric Finkelstein, a health economist at the nonprofit RTI Institute, wrote, “about half of the total cost of obesity-related health care is paid by the government through its Medicare program. For every American citizen, the out-of-pocket tax cost is an average $180.” This dwarfs the $13 billion businesses lose each year from obesity-related medical fees, absenteeism, and decreased productivity (as reported by the National Business Group on Health). Many of these obesity-related business costs are passed down to consumers in the form of more expensive goods and services.

Obesity, like many diseases, has no simple cure that alleviates its negative consequences. The government’s increased involvement and spending on health education, research and obesity programs, combined with our desire as a society to lead a healthier lifestyle, are the driving factors towards finding a solution. The question is, do we invest a lot of time and money fighting obesity now, or pay an even higher price down the road?

David Zinczenko:

A lot of people blame the obesity epidemic on lack of physical exercise, but I’m just not sold. The real rise in obesity started in the 1960s and 70s, and life wasn’t radically different between 1950 and 1970 — it’s not as though we were all working as farmers in 1950 and suddenly became sedentary in the seventies. (In fact, you can argue that we walked/cycled/ran/skied far less in 1950 than we do today, since the growth of the fitness industry.) Our lifestyles might be somewhat different now, but one thing is radically different: our food.

Starting in the 70s, manufacturers began to pump sugars into their packaged products, and the advent of high fructose corn syrup (HFCS) has only exacerbated our collective sweet tooth. HFCS has proven so irresistible to manufacturers because: a) it’s highly subsidized by legislation like the farm bill, which makes it cheap; and b) it’s a highly refined, stable liquid, which means it has a longer shelf life than table sugar and can blend seamlessly into products you wouldn’t associate with sugar — ketchup, for example, or marinara sauce. It’s no surprise, then, that we now consume 200 calories a day more than we did in 1970, and most of that comes from added sugars. By some accounts, we now consume up to 75 pounds of HFCS a year, and you’re likely to find it listed in the top three ingredients on the nutrition labels of products that simply were never intended to be sweetened — wheat bread, salad dressing, and crackers, for example.

As far as hydrogenated oils go, the sad irony is that they were created to replace the evil saturated fat, yet the trans-fats that came as a result seems to be far worse. Sure, some food manufacturers have taken strides to change (McDonald’s, Wendy’s, Subway, Frito Lay, and Nabisco, for example), but others aren’t even attempting to make the switch: each Keebler cookie has two grams of trans fats, while a chicken pot pie at KFC has a punishing 14 grams of the stuff. This, in turn, is wreaking havoc on our waistlines, and our tickers.

Another way to look at it is that our bellies are growing in direct relation to the both the size of the ingredient lists on our packages (it’s rare to come across one that doesn’t require a degree in chemistry to understand), and to the increase in restaurant and fast food portion sizes. Studies have shown that the average size of a dinner plate has grown 36% since 1960, while over the same period, the impact of your average-size McDonald’s french fries order has swollen from 200 calories to 600 calories. All of this — the unpronounceable ingredients, the behemoth portions, the stealth additives — works to confound our expectations about what our food will ultimately do to our bodies, which explains why we’ve become so clueless about estimating our caloric intakes. Two studies are particularly illustrative:

1) A University of Arkansas study found that people underestimated the number of calories in restaurant meals by as much as 600 calories.
2) And at Cornell, 85 grad students and nutrition scientists underestimated their ice cream servings by as much as 40 percent.

If experts can’t gauge what they’re putting in their bodies, how can the average American be expected to?