Steve Levitt is my Freakonomics friend and coauthor. He stands about 5-foot-11 and weighs 160 pounds. So he does not have a weight problem. But he has been thinking about our collective weight problem—but not thinking about it in a way that most people think about it. In fact, not even close.
Steve LEVITT: What we’ve learned over time, which is one of the most surprising things about obesity, is that the body has a very strong homeostasis device, which makes it both hard to gain weight and hard to lose weight. So, the calculation I did was a simple one. I eat probably 2,800 calories a day, and I like eating. So let’s just say I decided I wanted to go up to 3,300 calories a day, an extra 500 calories a day, and I wanted to do that for the rest of my life. Now you might think, well if you did that, that I would, my weight would essentially go to infinity, that that extra 500 calories would pile up and pile up and pile up. And the rough rule of thumb people use is that every maybe 3,500 calories turns into a pound. And so you would think my god you’re going to gain a pound a week for the rest of your life. It turns out I wouldn’t. Because of the way the body works, I would only gain 40 pounds.
LEVITT: So if I started this when I was a little younger, when I was 20, then I could have basically instead of being 160 pounds my whole life, I could have been 200 pounds my whole life and I could have had an extra 8.7 million calories over the course of my life. Now the experts agree that if I weighed 200 pounds instead of 160 at my height, it might cost me a year or two of life expectancy. And when you do all of the multiplication and the value of life calculations, it turns out that roughly every extra thousand calories I consume shorten my life enough that I would pay about a dollar. That’s the price. So it turns out to eat, you know, an extra, or maybe, so every extra Coke that I drink, can of Coke, is about 15 cents in shortened life.
Today on Freakonomics Radio: things you did not know about obesity — and what to do about it.
* * *
On today’s episode, we’re talking about obesity. Now, obesity is a problem that is at once terrible and wonderful. Wonderful because it represents our ability to produce delicious, safe, affordable food for billions of people, something that, not so long ago, doomsayers were saying was impossible. And it’s a terrible problem because, well, collectively we eat too much of that delicious, affordable food, much of which in fact is not at all good for us. Chris Economos, who studies obesity and childhood nutrition at Tufts University, says that more than one in three children and adolescents in the U.S. are overweight or obese.
Chris ECONOMOS: The obesity rates for children have tripled in the United States over the last 40 years. And there are dramatic health and societal consequences that result from that. Some are immediate and some are long-term particularly because childhood obesity leads to adult obesity.
Stephen DUBNER: And persuade me one step further that adult obesity in addition to being uncomfortable and, you know, unappealing for a lot of people for a lot of reasons, talk about the actual dangers of that in terms of morbidity, mortality, social costs, so on.
ECONOMOS: Sure, 66 percent of adults in the US are overweight and obese. And the health consequences are enormous. And they include the development of Type 2 diabetes, orthopedic problems, cardiovascular disease, a shorter lifespan and lost productivity. And there are serious social consequences as well. There’s isolation, mental health issues that develop as a result of first minor and then major depression. So it really is catastrophic when you put it together.
Catastrophic – and expensive, too. Obesity-related healthcare makes up roughly 20 percent of our total healthcare spending – which, in turn, represents nearly 20 percent of our GDP. So there are all kinds of reasons – financial, political, moral reasons – to address obesity. And there are all kinds of ideas, too. Today, we wanted to bring you some different ideas. Steve Levitt, whom you heard from earlier, tends to have a lot of different ideas. He’s an economist, at the University of Chicago. He also started a consulting firm, called the Greatest Good, which takes on regular consulting business but also, once in awhile, gets hired by a philanthropist or a foundation to tackle a problem like obesity. That’s what happened recently. The Robert Wood Johnson Foundation, whose mission is to, quote, “improve the health and healthcare of all Americans,” asked the Greatest Good to put together a one-day think tank on childhood obesity. We gathered up about a dozen people — nutrition experts and academics and some other interested folks — for a brainstorm. We should say here that the viewpoints that you’ll hear do not necessarily reflect the opinion of the Robert Wood Johnson Foundation.
Mary STORY: I’m Mary Story, I’m at the School of Public Health at the University of Minnesota.
Daniel KAHNEMAN: I’m Daniel Kahneman, I’m a psychologist. I know essentially nothing about this particular topic.
Peter ATTIA: I’m Peter Attia, I’m a cofounder and run a nonprofit organization in San Diego called the Nutrition Science Initiative.
Jim MARKS: I’m Jim Marks, senior vice president at the foundation.
Steve GORTMAKER: Steve Gortmaker of the Harvard School of Public Health.
Geoff CANADA: Geoff Canada of Harlem Children’s Zone.
Brian MULLANEY: Brian Mullaney, co-founder of Smile Traim.
Kelly BROWNELL: I’m Kelly Brownell from Yale, and I run a place called the Rudd Center for Food Policy & Obesity.
Chris ECONOMOS: Good morning. I’m Chris Economos, I’m at the Friedman School of Nutrition at Tufts University.
Eric OLIVER: I’m Eric Oliver, I’m a political scientist at the University of Chicago. I guess I’m here as a skeptic.
Bill DIETZ: I’m Bill Dietz, until June I was the director of the Division of Nutrition, Physical Activity and Obesity at the Centers for Disease Control. Now I’m an active citizen.
David LAIBSON: I’m David Laibson from Harvard. I’m a behavioral economist. My specialty is self-regulation and behavior change, getting people to save more.
We met down in Princeton, at the Foundation’s headquarters. I moderated the discussion. The only rule was that no idea was off-limits — no matter how absurd or politically incorrect or repugnant it might seem. This podcast is meant to give you a seat at the table. We begin with a question that Steve Levitt asked the group. The answer, as you’ll hear, shows just how insidious the obesity problem is.
LEVITT: Is there anyone in this room that thinks under the age of one we have a problem with nutrition for babies?
GROUP: Probably. Yes. Yeah.
ATTIA: And I would go one step further Steve, I would say that in utero we have some pretty good evidence to suggest that maternal diabetes, and I don’t even mean frank diabetes, I mean hyperglycemia, hyperinsulinemia during the critical period of development of fetal pancreas may play an enormous role in obesity, because there’s only I believe about a six-week window where the fetus’ pancreas is developing. If the pancreas develops in a high glucose environment versus a low glucose environment it develops more beta cells. So all of a sudden the child is born more predisposed. They’re not born insulin resistant, but now they’re more predisposed to being insulin resistant. And then when you look at…I do this, it drives my wife bananas when I’m in the grocery store I get so angry, I take photos of baby food. I turn it over and I’m like interesting that in baby formula number one ingredient, number one, high fructose corn syrup, ingredient number two modified corn starch, ingredient number three hydrolyzed…And it’s like well gee that’s interesting.
That was Peter Attia. He used to be a surgeon, now he runs a non-profit called the Nutrition Science Initiative. His hypothesis is that, of all the contributing factors to obesity, by far the greatest may be the prevalence of sugar in the modern diet—sugar in all its many, many forms. Some of these sugars are disguised, a lot of carbohydrates like bread and pasta, for instance, which most people don’t think of as sugary at all. And some couldn’t be any more obvious, like soda. Over the past few decades, the average American kid doubled his intake of soda. Overall, he eats and drinks about 180 more calories a day, which is at least a 10 percent increase, although lately, the data seem to show, that increase has plateaued. Most of these extra calories come from snacks. So say what you will about how kids are less active today than they used to be, how screen time has risen, the fact is that calories drive weight, especially the calories that don’t have any nutrition attached to them, which, by the way, tend to be the cheapest calories. So given all the empty, extra calories that kids are consuming, we probably shouldn’t be so surprised that a third of them are obese.
DUBNER: I’m curious whether anybody knows about children’s awareness of obesity as an issue among themselves, and how recent that is, and what the magnitude is?
ECONOMOS: I know a little bit. We just had a paper accepted, it’s in press, it was a national survey of children asking them what do you think about obesity? How aware are you about it? What do you think happens when a child is overweight and obese? And it’s all about how it’s not fun to be a heavy kid, stigmatized, isolation, bullying, all the things you’d expect. Pretty high awareness when you stratify by kids who self-classify as being overweight, they worry about everything more, not only being overweight, but their grades, getting in a car accident, not having money.
BROWNELL: Yeah, the way this plays out is that kids even at a small degree of overweight or a body that doesn’t look like everybody else’s are the subject to incredible teasing and bullying. I mean, the heartbreaking stories are just amazing. So I think Steve’s right, I think all of these things are a significant cost to society and to the individuals as well. And I would perceive it as two lines that cross, that in childhood the social costs are way higher than the medical costs. And then that changes over time. And then the medical costs would go in the opposite direction; they would be less significant in childhood, greater as age grows older. So these lines would cross. Now that doesn’t mean that the stigma’s not important to adults for wage penalties, marriage penalties, all these sort of things are very significant to people. But in childhood it’s especially extreme.
LAIBSON: Can I add just a twist to that which is I think kids are very, very aware of weight, obesity, and there’s all of that social stigma. But where I think they don’t perhaps have the sophistication of a 35-year-old adult is in understanding the mapping from what they’re eating to how over the next four or five years they’re going to become obese and how their exercise also maps into that. So even if they think obesity is terrible, I don’t want to be heavy, my peers who are obese are getting teased, they still need to understand how millions of actions translate into that outcome, and that is subtle. And I think it’s particularly problematic because of the delay between the action and the outcome. We know that organisms learn, humans other animals, learn really well when you do something and instantly you get feedback that’s clear; and learn terribly…when we talk about lots of animal studies where if the feedback comes four minutes later, the animal never learns.
OLIVER: David, can I push you on that question, because one thing you said that struck me is that children need to be…Sorry if I’m misquoting, but that children need to be able to sort of see the consequences of their behaviors, the way a 35-year-old adult could, and I think part of the difficulty with obesity, at least as it’s been framed, is that that 35-year-olds don’t do a very good job relative to their own sort of decision making framework. So I’m wondering if that’s even a reasonable standard to hold up with respect to kids in terms of their own capacity for making decisions that we might want them to make?
LAIBSON: I completely endorse that. It’s hard for a 35-year-old adult and I think it’s worse for the eight-year-old kid.
KAHNEMAN: I just want to reinforce David’s implied point. I saw the meeting in terms of behavioral change as how do you change parental behavior.
KAHNEMAN: Changing child behavior, forget it. But parental behavior is going to be really difficult.
ECONOMOS: I just wanted to insert something just a little bit different to think about. I just finished a study on new immigrants. And you know many of them arrive here from an environment where food is limited, it’s highly ritualized, there’s no snacking, and you watch them navigate this obesogenic environment in a short amount of time and you see obesity manifest very quickly. And one of the underlying things that we’re looking at carefully is time tradeoffs and time use, which leads to behaviors that cause obesity. So as we think about this problem, I’m not an expert on time tradeoffs, but there’s a whole literature on it, and we’re studying it. And I think it’s important because it leads people directly to the foods that we’re describing and the overconsumption that results. So I don’t know how to factor it in, but I think it’s extremely important, and to watch it unfold in a short amount of time is fascinating. It’s basically what many of us experience over decades.
That was, in order of appearance, Chris Economos, Kelly Brownell, David Laibson, Eric Oliver, and Daniel Kahneman. Geoffrey Canada runs a non-profit in New York City called Harlem Children’s Zone. In the beginning, it focused on education
and drug prevention. But over time, Canada says, obesity became a big deal.
CANADA: Well, you know, it started out being a small aspect of our work until we realized that about 40 percent of our kids are obese. It is a huge epidemic in our community, and so while we’re preparing kids for college, we want these kids to become productive members of society. You know, one of the things that happen in a place like Harlem is that it’s almost like a black hole of taxes. All of the tax dollars come in, we’re paying for prisons, and jails, and reform schools, and emergency visits to the hospital, and special education services. And so few folk are able to work, and work long periods of time, that you don’t get folks actually contributing back to society. If my kids who are going to college, which they will, all end up getting sick in their thirties and forties, and their health care costs simply skyrocket, again we’ve not solved that equation. So we felt that it was very much part of our job to not just get these kids in college, but to get them in college healthy so they can come out and have full, productive lives. And we can really make sure that they can contribute to society.
Fighting obesity, Geoff Canada told the group, is in some ways harder than fighting drugs, or school dropouts.
CANADA: I mean we got into this because of the morbidity and mortality issues 10 years ago just looking at what was happening in Harlem, and you could see the end result of people in wheelchairs, missing legs, and feet, and stuff like that. And you know, this is a horror show. What’s causing it? And it all traced backwards to this issue of what’s happening with young people. But it’s become, I think, for me, a lot more complicated because some of this is I think based on what parents and kids do. But I believe a huge percentage of this is based on what commerce does in certain communities. And you know, once I made the statement and I still believe it, I never thought I was going to get rid of drugs in Harlem. I just wanted drugs to be sold in Harlem the way they’re sold in the suburbs, right, quietly, anonymously, that it’s not pervasive like this is the way of life and this is the main commerce of this community. I feel the same way about a lot of what’s happening in the inner cities. It is almost impossible to get healthy things, and it is very easy to get all of these unhealthy things. And so even as we’re thinking about kids, and adults, and families, I’m worried that as the market has depended on these communities to consume more and more of these unhealthy foods and beverages, we’re up against more than just a parental sort of concern because of all of the commercials, the advertising, the accessibility, and so all of that to me suggests that some communities are more vulnerable than others even if you could sort of deal with lots of the challenges that families and individuals have. So that’s one issue. I have become increasingly convinced, and I’m no scientist, that a lot of this is addictive behavior, that the sugar that folks consume, it is an instant feedback, eating a Twinkie. I don’t know, maybe I’m the only one that gets that sort of satisfaction from doing it, but lots of families I think are using food, right, because the rest of their lives are so horrible that this is something that you can enjoy and now Geoff wants to take that from you too.
Coming up on Freakonomics Radio, some palatable and not so palatable ideas to fight childhood obesity.
LAIBSON: Imagine a world where I could consume a parasite that could not reproduce and it would go into my bloodstream and it would basically make the things that I eat ineffective as nutrients and they would flush out of my body.
* * *
Steve Levitt and I recently spent a half-day running a brainstorming session for the Robert Wood Johnson Foundation, on the topic of childhood obesity. One of the only ground rules was that no idea was considered beneath discussion. Did you know, for instance, that quitting smoking – which is plainly good for your health – usually leads to a significant weight gain? So the good news is that the American smoking rate has fallen from 45% in the 1950’s to about 24%. But the bad news… well, here’s Bill Dietz, the former CDC official.
DIETZ: The estimates are that the reduction in tobacco use accounts for maybe 20 percent of existing obesity.
DUBNER: Right, so, you know…
MARKS: Very little in kids.
DUBNER: Very little in kids. Right.
O.K., so no one is going to push for, say, putting cigarette machines in schools to fight obesity. But we did want to hear any other ideas from our participants. So we started a lightning round.
DUBNER: Should we put pressure on? All right. What do you got?
STORY: In grocery stores, unhealthy foods would have to be restricted to certain locations such as the back of the store.
DUBNER: Oh, like the porno department in the video store idea.
ATTIA: Abolish sucrose and high fructose corn syrup. Don’t even…Forget about taxing them; pretend they don’t exist, take them off the face of the earth.
DUBNER: All right.
GORTMAKER: Right now businesses can write off all the money they spend marketing to kids as a business expense. Just eliminate that tax deduction.
CANADA: I would say start a real public health campaign aimed at the big food companies where we should be talking about how many people have been killed by Cokes and Pepsis and whatever. And just make it that they feel the pressure to reform their practice.
MULLANEY: Like a list of shame?
CANADA: Just a big shame, just a big national shame thing with all the big companies.
BROWNELL: In the spirit of completely impractical things, I would want to get rid of marketing of any product to any human being.
DUBNER: No, I can see that’s viable, yeah.
BROWNELL: But what I would do would be to sequester it out there somewhere so that people could voluntarily go find it.
DUBNER: So it’s all opt in marketing?
BROWNELL: It’s opt in marketing, and so billboards and TV commercials and stuff would be forbidden, because it just seems to me that marketing does have some benefits, obviously for the companies, but to the individual it has a small number of benefits, but a huge number of downsides. And of course food, would get caught up with this in a positive way.
DUBNER: Wow, thanks. Chris?
ECONOMOS: So I’m going to focus on parenting and the schools. So the first one is to hold our educational system accountable to deliver nutrition, physical activity, and media literacy by requiring standardized tests to assess it. So measure the baseline, set some benchmarks, and move the entire system along. And treat it as important as some other things. And the second is to change the home environment by incentivizing parents through health insurance, worksite, or welfare benefits to make a commitment to healthy parenting.
DUBNER: Great, Eric.
OLIVER: I think we need to have a paradigm shift and embrace a paradigm shift and really let go of obesity as a target of health remediation and just focus everything on malnutrition. It seems most of discussion here is really about childhood nutrition. Obesity has a lot of cultural baggage associated with it. I think it’s an imprecise marker, even though it’s an available marker. And with Michelle Obama’s campaign, I’m afraid that childhood obesity has become politicized in a partisan way now. And that makes it more difficult as an issue to focus on. And I just wonder if we would do better by making this an issue of malnutrition rather than weight?
LEVITT: Wait, let me tweak this…So I think the word malnutrition actually doesn’t work very well because malnutrition implies hunger. But whenever you say like metabolic…
LEVITT: No, but you have a bigger one than that. What is it?
ATTIA: Metabolic derangement.
LEVITT: Derangement. Yeah, it seems to me…
ATTIA: It’s not going to be a bumper sticker is it?
LEVITT: I don’t know…
ATTIA: Stop metabolic derangement now.
LEVITT: But I like the idea of putting together what you two are both saying, which is that if you could get a fresh start, if you had the right marketing behind the idea that there’s this package of horrendous disease states, which you’re heading towards, and actually the marketing, marketing around…Metabolic syndrome doesn’t do it for me.
DUBNER: You like derangement better than syndrome?
LEVITT: I like derangement better, though I don’t know what it means. But it seems to me that actually marking the concept that there is this one thing, which has 100 bad things with it, just strikes me as a really interesting way of trying to reframe the idea.
DUBNER: But marrying that to where Chris was going with parenting, which I really applaud, because I think parents get off the hook really easy, way too easy. Because most kids will eat what they want to eat when it’s available, right? And we’re the ones that make it available. So what about using…I actually like malnutrition. I think it connotes the fact that yes, we used to have the problem that people were ill because they didn’t get enough to eat. Now they are still ill because they’re just eating too much of the wrong thing. I actually find that paradox appealing. But that’s just me personally. But what if you could marry the concept of malnutrition with shaming. What about shaming the parents? What about this is a crusade that parents…
MULLANEY: Well that’s sexy, if you mailed 100 million homes, so “Is your child suffering from metabolic derangement?” you’re going to read that. “Is your kid fat?” goes right in the trash.
DUBNER: Exactly. Right.
GORTMAKER: Just picking up on this, one of the things we found in our research, and we actually haven’t talked about this yet, is when you focus on obesity in kids, you also have a side effect that you’ll increase eating disorders among kids. And that has big costs also. We found that by just focusing on healthier eating and physical activity, you can reduce obesity in kids and reduce eating disorders at the same time. So I think I agree with don’t focus on fat among kids or obesity as a topic, but focus on the behaviors and the environment that you want to change.
DUBNER: Several of the most intriguing ideas in the lightening round came from one person, Harvard economist David Laibson.
LAIBSON: I very much like the idea of a tax, and I have a feeling that to an economist that’s delicious.
Laibson proposed a grand experiment, where in some places you’d put a tax on unhealthy foods and in other places leave prices the same, to see how consumers would respond and how much it would cost to nudge people away from those cheap, empty calories. Laibson also had an idea for a piece of caloric-monitoring jewelry.
LAIBSON: Imagine you had a bracelet that a kid wore, or an adult wears, if I had this it would affect my behavior. And as I go into a meal it starts registering 200, 700, 900, 1,400 calories. And as it tells me I’m eating more and more in this feeding episode it starts to change it color from green, to yellow, to orange, to red, and then it starts pulsing red, red, red, red once you get way out of range.
STORY: And then squeezing it tighter and tighter.
LAIBSON: There are many aspects of this that may seem effective if the technology could be developed. And we could put that issue of how to develop the implanted probe so that you actually can get this external measurement. Though there are actually increasingly external diabetic measures that can pick stuff up like this. But the reason I mention this is that it goes back to the reinforcement learning point that I made earlier, which is organisms are very good at learning when the stimulus and response are tightly linked in time. And they’re terrible at learning when stimulus and response are separated by, like, 10 minutes, let alone five years. So if we could somehow help people realize what you just ate is doing it now, I think people would feel much more negativity towards overeating.
And David Laibson’s final idea? Let me just say, a few of you might find this a bit distasteful.
LAIBSON: Imagine a world where I could have, you know consume a parasite that could not reproduce and it would go into my bloodstream and it would basically make the things that I eat, you know ineffective as nutrients and they would flush out of my body. And because the parasite doesn’t reproduce I can control how much I want. And if I’m too skinny I don’t take the parasite, and if I’m getting fat, I take the parasite. So what I’m proposing is a world where, hey we love eating, I loved my Reuben sandwich last night, and I could have more of those in principle, up to a limit, if I had an ability to kind of turn off my body’s capacity. My body is so efficient at turning calories and nutrients into more of me, and if I partially incapacitated that in a way that we can control, in a way that was safe, and a way that, you know, wouldn’t it be fantastic? Because then the food companies could sell more food!
LEVITT: Okay, so it’s always been my belief that when there’s one economist in the room you feel like you’re really smart, and when there are two you feel really dumb. So just an example of this, so David talked about his parasite, I spent all afternoon learning about tapeworms yesterday because all economists think exactly alike. And I came to believe that obviously you can do better than the current tapeworm, but there are some pretty good tapeworms out there right now. There are certainly bad tapeworms. There’s a fish tapeworm it turns out which you wouldn’t really want in your body. As far as I can tell, I think it was the beef tapeworm…There’s all sorts of tapeworms that actually are not perfect, but are pretty good already at doing what David wants them to do. And I’m sure if we could domesticate them with the kind of effort that we put into dogs and cows and things, we could make tapeworms some of the most loyal and serviceable pets that would ever be out there.
That was Steve Levitt and, before him, David Laibson. As you can tell, obesity is one of those problems that is so tricky that some of the possible solutions are bound to be outlandish. It’s hard to say how, or if, any of the ideas you heard today will be acted upon. Steve Levitt and I were just the facilitators of this discussion; other people will be the executors. When it was over, Levitt and I held a brief post-mortem…
DUBNER: We closed the proceedings, with an experiment, something you’ve dreamed about, that you’ve talked about for years and years, why don’t you describe that and tell me what effect you think it had?
LEVITT: So one of the issues we didn’t talk a whole lot about during this conference was self-control and the fact that many people who want to lose weight are unable to do so because they, in the moment, end up eating more than they would like to and regretting it later. So there are different solutions to that. One very aggressive and invasive solution is bariatric surgery, which makes it difficult for you to eat a lot. But my father really put the idea in my head many year ago when he suggested that if you really don’t want to gain weight, whenever you start to think you’re hungry you should carry around a little jar of, like a baby food jar, that’s filled with human vomit, and just open it up, take a whiff, and you won’t have any desire to do it. Now, it turns out it’s operationally hard to figure out how to get vomit into a baby food jar. But my friends at www.liquidass.com have actually done that favor for us. So I recently discovered that you can buy in a bottle, a little spray bottle or squeeze bottle the most revolting smelling things in the world, of which all you need to do is take one or two whiffs of them and you think you don’t need to eat for a long time after that. And so we brought it out to show the obesity researchers and to take their pulse on it. So as we passed these bottles around the room and invited people to have a sniff, I noticed that almost all of the outsiders, the economists, the sociologists, the political scientists, many of them took a good deep whiff, but none of the obesity experts went anywhere near. Not one of them wanted to take a whiff of that stuff. I think it tells you something.
DUBNER: What does it tell you?
LEVITT: I’m not sure, but I’m going to have to think about it. But the division in response was notable.
DUBNER: I mean, I realize it’s kind of jokey, but do you think it’s a personal responsibility idea here? In other words, do you think the experts have come to divorce the idea of obesity and personal responsibility to the point where the problem is not really on the end user so much and they don’t need to work so hard?
LEVITT: It is an interesting point you raise that I do believe that the outsiders were much quicker to think about the problem at the individual level about self-control, about why do individuals become obese, whereas the experts in the field think of it much more in environmental terms, and what are the food companies doing, and how are things marketed, and how the individual is not really the actor, they’re the acted upon. It is an interesting difference.
DUBNER: Dwayne from the foundation, I have to say, he stuck his nose deep in each. And he had of course the classic quote. Do you remember exactly what he said?
LEVITT: “Ass and vomit smell different.”
DUBNER: He said something like, they are really not the same.