Colloquy

Why We're Obese—and What We Can Do about It

Episode Summary

Sara Bleich, PhD '07, former director of nutrition security for the Biden administration, on the obesity crisis and what policymakers, communities, and individuals can do to fight it

Episode Notes

Obesity in the United States has reached epidemic proportions, affecting millions of Americans and costing the healthcare system billions of dollars each year. As is so often the case with disease in this country, communities of color suffer disproportionately.

Public health expert Sara Bleich, PhD ’07, says it’s time to deal with obesity as the urgent crisis that it is. A professor of public health policy at the Harvard T.H. Chan School of Public Health and former director of nutrition security for the Biden administration, Bleich says the disease is largely preventable but to make progress, the country must deal with persistent inequities in the healthcare system—and the structural racism that underlies them. Join us this time for a conversation about obesity, public health, and race.

Episode Transcription

This extended transcript has been edited for clarity and correctness.

In preparing for our conversation, I read a bit about your background and I wonder if you could tell your story of growing up in Baltimore and spending your allowance at the corner store. What did you notice about the food and drinks they sold there, and how can it help us understand obesity in the United States today? 

That's a great question. So I was raised in inner-city Baltimore. My parents still live in the very same house that I grew up in. And I had a really interesting family growing up. My parents were both public school teachers, very concerned about health, so our family was the one eating tofu ice cream when no one else thought it was cool. 

And we would get an allowance, and that was all the money that we had to spend for the week. And when I was probably about the age of my daughter, so around 12, my allowance was seventy-five cents. And a block away, there was a corner store. 

And I loved potato chips. And I also used to love a candy called Now and Laters. So I would always go to the corner store and buy a bag of red hot potato chips for fifty cents, and then I'd buy some packs of Now and Laters. 

I was doing that one summer and I noticed that when I put on my school uniform at the end of the summer, it didn't fit. So I asked my mom about it, and she said because you ate so many potato chips. 

That same time, I went to the dentist and found out I had a number of cavities. And so that was like the first indication for me that what you eat matters for your health. And, again, the family that I grew up in—no soda, sweets were very limited. Like, it was a big shift in my diet. 

One thing that I have really taken away from that experience growing up and have incorporated that into my research career is that environments matter a lot. In Baltimore and Philly—and pick your urban city—there are tons of corner stores. And corner stores tend to have a very small footprint but they are chock-full of processed foods and sugary beverages. And that's because it's very attractive to consumers, and it's very low cost. 

What we know, if you sort of step back and say, well, what is happening to the country when it comes to obesity? We generally know that it is being driven by an overconsumption of calories, particularly among adults. And that the type of calorie matters. Ultra-processed foods are worse for us. 

There are three major things that drive what we eat—price, convenience, and taste. When I was 12 and I was taking my seventy-five cents to the corner store, my selections were a perfect example of that strong preference that we have. And it is helping us to understand why as a country we have gotten so heavy. 

You mentioned overconsumption of calories. That was one of the conclusions in the 2008 article that you co-authored for the Annual Review of Public Health, "Why is the Developed World Obese?" Can you describe the landscape of obesity in the US today? How prevalent is it? How has it progressed or evolved in the fifteen years since the article? And how does the landscape change for communities of color and low-income folks? 

Well, first off, for folks who are not familiar with how to determine if a person is obese or not, or if a person has obesity, it's your weight in kilograms over your height in meters squared. So take a person who's five feet, four inches tall. That person has obesity if they weigh about 174 pounds or more. 

So my first dissertation paper is the one you just mentioned answering the question why is the developed world obese? It's a simple, straightforward question. It took me two and a half years to write that paper because it involved pulling together lots of different data sources. 

And the punchline is that the reason the developed world is getting bigger—and as this paper focused on adults—is because we're eating too many calories. We did a subsequent paper among children and found that it's more of a mixed bag. In some cases, it's too many calories, and in other cases, it's too little physical activity. But part of your question is, what is the state of the world right now?

So if you look across the country, 42 percent of adults have obesity; 20 percent of children have obesity. These are extremely high numbers. If you look back fifteen years, it was about 30 percent of adults. It has gone up almost 10 percentage points. And for children, it was 17 percent. If you pan back even further, when we started seeing really big increases in this country was in 1980. And over the period from 1980 until now, it has tripled among adults and quadrupled among children. It is a significant health problem. 

The other piece of this is while obesity affects many, many people in our population, it does not do so equally. So Black and brown populations are disproportionately impacted. For example, if you look at Black adults, it's 50 percent of that population; for children, it's 25 percent. And so you can just look at those numbers, and they're much, much higher among certain groups. 

Now, if current trends continue, what would obesity look like? And there's a series of papers in the New England Journal of Medicine that were led by Zach Ward, who's a faculty member at the School of Public Health, and the first one focused on children. And it asked the question: What would childhood obesity look like for 2-year-olds today when they turn 35 if present trends continue? 

What it found is that 57 percent of today's 2-year-old children would have obesity by the time they turn 35. And, not surprisingly, it would be higher among Black and brown kids once they became adults versus white kids. 

The second paper that he did looked at adults. And it looked at the predicted probability of obesity by 2030. And what he found is that half of US adults-—right now, we're at 42 percent. He predicted that half of US adults are expected to have obesity by 2030. 

And that, at that same time, severe obesity—which is carrying about an extra 100 pounds—would be the/most common category for Black adults. Again, it’s a very significant public health problem but disproportionately impacting certain parts of the population. And what we see among racial ethnic groups is the same thing that we see by income. Lower-income populations tend to have higher risk for obesity. 

So why did we see that spike beginning in the 1980s? Was it—did food companies get better at making cheap, high-calorie, tasty foods?

A major thing that happened is that food was able to be preserved on shelves in ways that weren't possible before. It was very inexpensive and to do it has gotten easier and easier over time. 

So, when I was little, if I wanted chocolate chip cookies, my mom or my dad would go in the kitchen and make them. And that would take several hours. Now, if you want chocolate chip cookies, you can walk down to the vending machine and buy them for a couple of dollars—or, when I was younger, for fifty cents. So the mass production of food and its much longer, stable shelf life has made so many calories available. 

There are all these cues in our environment that make it very easy for us to overconsume, and our lives have become more sedentary. But, again, the primary culprit is we are eating too many calories. 

On any given day, it doesn't take that many calories to tip someone towards obesity. We're talking about a few hundred calories. And it varies based on someone's body weight, but it doesn't take a lot. So if 

you're having an extra can of soda, a few Oreo cookies, an extra handful of pretzels, over time, that can tip someone towards obesity. And if you pan out even further and think about the environment, there's food everywhere. And it wasn't the case when I was growing up. There are many, many more food outlets today and they’re available 24 hours a day. 

I want to talk some more about the role that race plays in the prevalence of obesity. But before that, we know that obesity increases the risk of developing a range of illnesses—heart disease, hypertension, some kinds of cancers. Obesity was also one of the leading risk factors for severe COVID-19 outcomes. What’s the scope of the condition’s impact on public health in the US? I mean, how much healthier would we be if it was a marginal issue? And how much is it costing the health care system each year? 

Obesity is a serious medical condition. What most people appreciate and know is that if someone has obesity, it impacts their life. And you mentioned things like diabetes, heart disease, and some cancers. So obesity impacts morbidity. But what many people don't appreciate is that obesity also leads to premature death. 

For example, there's a recent study in Lancet that found out that excess weight contributed to more than 1,300 excess [SG6]deaths per day. So that's nearly 500,000 per year. And that was in the United States in 2016. This increase in the total mortality rate of nearly 18 percent resulted in nearly 2.4 years of life expectancy loss. 

The problem of obesity, because of this mortality and morbidity, is also very expensive. The estimates vary, but there is one study that puts the direct medical costs of obesity at $172 billion per year. 

And if you look at poor nutrition more broadly, and you add into that all the lost productivity that is due to poor diets, you can't go to work, you're in extra doctor's appointments. The annual price tag in the US is estimated at $1.1 trillion. 

And you mentioned COVID-19. There was a study during the pandemic that found that nearly two-thirds of hospitalizations for COVID-19 were related to obesity, diabetes, hypertension, and heart failure. There's a relationship there between someone having diet-related conditions and increased susceptibility to COVID-19. 

I've often heard scientists talk about a genetic predisposition to obesity. But is that oversold? Is obesity mostly preventable?

The answer is yes and no. The yes part of it is that we all have a genetic profile, and that genetic profile makes us more or less susceptible to our environment. But I think the stronger answer is no. Genetics cannot explain the rapid rise in obesity that we've seen over the past several decades. It just doesn't change that quickly. And we know that changes in the built environment, which increase opportunities for eating and reduce opportunities for physical activity, are the primary culprit. 

As I mentioned, there is variation in how two individuals who are in the same environment can have different reactions. I think the simplest way people should think about this question about the role of genetics is that obesity is more closely tied to their zip code than it is to their genetic code. 

And so if it's not genetics, then what is driving this rapid increase that we're seeing? And this, again, goes back to the issue of imbalance. So you're either eating too much or exercising too little. And that is causing the weight to either go up or go down. And, again, among adults it's primarily food. And among children, it seems to be a little bit of both. But to go back to where you started, I strongly believe that much of obesity is preventable. 

Before we talk about health outcomes in Black and brown communities, can you say a bit about how you define structural racism?

The important thing to know about structural racism is it is not simply the result of an individual having a private prejudice. It is something that is produced and reproduced by laws and rules and practices that are sanctioned, and even implemented, by various levels of government and potentially embedded in the economy and social norms. 

A concrete example is redlining. And what that refers to is discriminatory government-sanctioned practices that put services, like financial services, out of reach for Black people. A good example is mortgages to buy a home. 

Redlining has officially been over for decades, but its impact is still seen today in most American cities in the form of broad social disinvestment, especially in neighborhood infrastructure like green space or roads, and in services such as schools. 

The key thing to know about structural racism is that it is real. It reaches back to the beginnings of US history. It stretches across our institutions and our economy. The second key thing to know about structural racism is that it harms health by increasing disease risk and by reducing opportunities for a healthy life. 

You mentioned redlining right there. You've also written about how the institution of slavery and then following that, under Jim Crow segregation and the ongoing crisis of mass incarceration, are all historical examples of policies and practices that have created and maintained structural racism in the United States. I wonder if you can talk about any of the other factors that have contributed to the racial disparities in obesity today or, if you like, health inequities in general.

The important thing to know is that health disparities are not by chance—they are by design. They are the direct result of intentional policies that limit things, like access to care, or create social circumstances that increase the risk of disease. You mentioned slavery, which in this country is our original sin. And the legacies of slavery still impact just about every aspect of American life. 

If we hone in specifically on disparities in obesity and other diet-related diseases, those are associated with decades of structural limitations to retail food outlets that sell healthier foods. If you just drive through various neighborhoods, you can easily see the differences in the types of grocery stores that are available. 

If you're in high-income neighborhoods versus low-income neighborhoods, or historical—or neighborhoods—start again. Or if you’re in neighborhoods that have a high representation of historically

underserved populations versus white neighborhoods. The same is true if you look at the spread of playgrounds and green spaces for folks to go and be physically active. 

What else do we know about historically underserved populations? We know that food companies directly target Black and brown populations with marketing for unhealthy food. We know that chronic stress due to experiencing racial discrimination can increase the severity of obesity. 

We know that children with obesity are likely to become adults with obesity, and that obesity is higher, as we already talked about, among Black and brown children. We know that it's harder to access care if you're from a historically underserved group. And we know that there is real and perceived systemic racism when care is sought. 

How do biological and behavioral mechanisms like inflammation, immune response, co-morbidities, and preventive behaviors interact with structural racism to create a vicious cycle of obesity and poor health outcomes for people of color?

We can look at COVID-19 as a way to understand how various mechanisms are interrelated. As I mentioned, when a person experiences racial discrimination, it can contribute to chronic stress. That has been linked to obesity risk. 

We also know that discrimination is linked to higher levels of inflammation among Black adults. So chronic stress can make someone more vulnerable to infection from COVID-19 because it can lower your body's ability to fight off an infection. 

Now, we get to the more uplifting part of the conversation, where we can talk about some potential solutions. You've proposed some that can address the root causes of public health problems and promote health equity. One of them is expanding health insurance coverage, especially for low-income and uninsured populations. So how would this help reduce the burden of obesity among people of color? 

At the risk of stating the obvious, people without health insurance have less access to healthcare. And uninsurance and underinsurance are higher among historically underserved populations. Now, the delivery of obesity treatment is imperfect, and there are varying qualities depending on factors like provider training. 

But research strongly supports the use of lifestyle modifications. These are things like intensive behavioral therapy. It also supports weight loss medications and surgery when it makes sense given a person's weight profile. But these options are cost-prohibitive for many people without insurance. And among those with insurance, coverage for interventions can vary dramatically. 

Medicaid provides health insurance to about eighty million individuals who have low income each year. It is federally funded and state administered. Despite strong evidence about effective obesity treatments, as well as endorsements by major professional associations, only a handful of Medicaid state agencies cover all the components of obesity treatment, and only some cover bariatric surgery. Medicaid agencies

are required to cover nearly all medications approved by the Food and Drug Administration. But anti-obesity medications have been excluded from this requirement. And, as a result, coverage remains optional and sporadic. 

I mentioned that a typical Medicaid enrollment is about eighty million people per year. This number ballooned to about ninety million during the COVID pandemic due to factors such as declining income as people lost their jobs and key flexibilities that made it easier for folks to stay enrolled. And this was known as continuous Medicaid enrollment. That continuous enrollment ended in March 2023. This means that people will not automatically remain enrolled and will have to go through a renewal process. According to government projections, about fifteen million people are expected to lose coverage. This has implications for federal nutrition assistance programs, which serve one in four Americans over the course of a year. And that's because millions enroll through Medicaid. 

So the punch line here is that health insurance is an important frontline defense to help people who have obesity get the treatment that they need. But that insurance is not available to all low-income and historically underserved populations. 

Another solution that you suggest is increasing access to healthy foods, especially in areas where there are limited or no options for affordable and nutritious food. So how would we implement this on the governmental, community, and individual levels? 

This is a great question. I have spent a lot of time thinking about this, both in terms of research and in my time in the Biden administration. 

So let's start on the federal side. The US Department of Agriculture runs a suite of fifteen nutrition

assistance programs. As I mentioned, together, they serve one in four Americans over the course of a year. And the largest one is called SNAP. That stands for Supplemental Nutrition Assistance Program. It used to be called food stamps. That program helps forty-one million Americans buy food each month. 

Another large one is the National School Lunch Program, which feeds about thirty million children each day. And then a third one is the Special Supplemental Nutrition Program for women, infants, and children, which is known as WIC. And that serves over six million pregnant and postpartum women and infants up to the age of 5, including about half of the infants born in the United States. 

There have been a number of historic changes during the first few years of the Biden administration to help drive towards better nutrition, which as a byproduct should help improve obesity. Let's focus on SNAP first since that is the largest population—again, forty-one million Americans each month. 

There is something called the Thrifty Food Plan, which is basically the calculator for figuring out how big the monthly SNAP benefit should be. That was recalculated in October of 2021. As a result, monthly SNAP benefits increased by 21 percent, or thirty-six dollars per person per month. This was the first permanent increase to the purchasing power of SNAP benefits in more than four decades. Each year,

SNAP is designed to adjust for food inflation, and food prices obviously have been going up in recent years. In October 2022, the SNAP program experienced one of the largest inflationary increases in its history. It was 12.5 percent. As a result, a family of four that qualifies for the maximum snap payment received $939 per month in FY23. 

Another key change to the SNAP program is something called SNAP Online. Prior to the pandemic, there were only five states in which participants in the program could use their benefits to shop online. As of earlier this year, SNAP online is now available in all fifty states and the District of Columbia. So if you combine these two things—increasing the size of the benefit and the ability to purchase food online—this combination is really putting healthy food within reach. 

Another thing to bear in mind is that there were all these flexibilities put in place during COVID-19 to help people access food, like health insurance, among many other things. This was part of the public health emergency. These policies have been sunset. One of them is the SNAP emergency allotments, which ended in March of 2023. And those started in early 2020. That means that households are receiving about ninety dollars less per month. And this is even as food prices continue to increase. 

Essentially, those allotments were allowing all SNAP households to receive an additional ninety-five dollars in monthly benefits, or an additional benefit up to the maximum benefit for their household size. So that's the SNAP program. 

In the pipeline, there are proposed changes to some of the nutrition assistance programs that could increase people’s access to healthy food. For example, the Department of Agriculture has proposed rules to better align school meal standards and the WIC food packages with the latest dietary guidelines for Americans. What’s really significant here is that for the very first time, the proposed rule around school meal standards considers reducing added sugar. And you can think of the WIC food packages essentially as a prescription program to help people eat healthier. 

There's also a brand-new nutrition assistance program that's going to begin in the summer of 2024, and it's called the summer electronic benefit transfer program. It's going to provide resources for families whose children receive free or reduced-price meals during the school year so they can receive food during the summer. This program is expected to give more than twenty-nine million children about forty dollars per month in benefits. 

So that's a bit about federal actions. Let me mention one key state action, which is Healthy School Meals for All. This is a policy that aims to reorient the school meal program from being an ancillary service to an integral component of the school day, like how we think about books and desks and computers. 

Currently, there are eight states that have permanent programs providing Healthy School Meals for All. And then one state has launched a two-year effort that began last year. The thing to know about school meals is that they are the healthiest meal of the day for many children. And they have been linked to reduced obesity rates among children living in low-income households. 

Now, the problem of obesity, which we have been talking about, is a whole-of-country problem and so we have to look to whole-of-country solutions. We cannot just look to the federal government and state government to solve this. For example, the private sector can help by reducing the marketing of unhealthy foods, especially to Black and brown populations. Supermarkets can be helpful by prominently displaying healthy foods and offering price discounts. And the list goes on and on and on. But there is a need for the private sector, for philanthropy, to step up and think about what we can do in this space. How can we reformulate healthier foods? What can we do to help address this ever-ballooning problem of obesity? 

Obesity is a complex problem. It involves a lot of different factors— genetics, behavior, environment, policy. So what are some of the most effective interventions or policies that can prevent or reduce obesity at the individual and population levels? You’ve mentioned federal policies, government policies. You started to talk about some stuff that the private sector can do. Anything else you want to talk about? 

There is a team at the Harvard School of Public Health that is led by Professor Steven Gortmaker. And what they focus on is identifying cost-effective solutions for obesity. Why is that important? Because the number one question from policymakers is not just does it work but also how much does it cost. And so their work has identified a number of cost-effective approaches that can meaningfully move the needle around obesity. And so I want to highlight three. 

One is WIC, which we've already talked about. Essentially, WIC is—you can think of it as a prescription program. It's providing supplemental foods to meet the nutritional needs of pregnant and postpartum women, their infants, and children. And it's been shown, as I mentioned, to reduce rates of childhood obesity. What’s interesting is that the proposed rule right now to further strengthen the WIC food package

is likely to make it even more effective at preventing obesity. And this is something that will have to be evaluated in the future. And just to circle back to a point that I touched on, heavy children tend to become heavy adults. So prevention of obesity in childhood is critical. 

A second intervention, which we've touched on, is school meals. So, again, they reached thirty million children a day. An analysis led by Erica Kenney, who's at the School of Public Health, found that updates to school meal standards prevented hundreds of thousands of cases of obesity, particularly for children living in households below the poverty line. And since these improvements among children in low-income households are concentrated among that group, that is really good evidence for improved health equity. 

And, again, the new proposed rule to strengthen school meal standards to reduce added sugar is very significant. And if that goes into policy, that will happen in the 2024-2025 school year—so in the not-too-distant future. 

A third intervention is beverage taxes. Sugary beverages are a leading source of added sugar in our diet and are strongly associated with weight gain and obesity. They also are disproportionately consumed by historically underserved populations that, as we've talked about, are at higher risk for obesity. Randomized experiments and large longitudinal change studies have shown that reducing intake of sugary beverages reduces weight gain. 

There have been evaluations of taxes that have been implemented in multiple US cities— Berkeley and Oakland and San Francisco in California, Philadelphia in Pennsylvania, and then in Seattle, Washington. And they have indicated effectiveness in both reducing sugary beverage sales and reducing consumption. And cost-effective analyses have indicated that these taxes are cost savings, which means they are inexpensive to implement and they are effective. What makes these taxes even more attractive from an equity standpoint is that in some cases, the revenue is used to improve population health. 

I am intentionally highlighting policies focused on prevention rather than treatment. That is not because treatment is not important, but it is so much harder to lose weight than to keep it off in the first place. And if we want to make inroads around the problem of obesity, we have to focus on prevention. 

One of the ways to help with prevention is through communication. You've been involved in communicating with the public and the media about health and behavior as an educator, as a researcher, and also as a government official. What are some of the best practices or strategies for effective health communication, especially in an age of misinformation, disinformation, and depolarization? 

This is a great question. First, let me say that many folks in graduate training are not receiving communication training. And I would say that if you are interested in helping your research have legs and impact, think about getting it outside the ivory tower. Think about, how do I take this important knowledge that I've created and get it in front of policymakers that can effect change on people whose lives might be impacted by this new information. 

But the number one rule of communication is knowing your audience. You should speak differently to a scientific audience as compared to a group of teachers or students. It's really important to know who you're talking to. 

The second thing is putting your bottom line up front. Often, we bury the lead, and we take a while to get to our point. I call this the BLUF—your Bottom Line Up Front. Start with your main point, provide your supporting evidence, wrap it up with a bow at the end, and then here's the important thing, stop talking. 

So much of our training as researchers is to present an issue and then give all the reasons—in this case, limitations—why we should think about whether or not the results make sense. When you're trying to communicate with policymakers, folks outside of academia, that piece is less important. And so I really encourage you to be concise, to be brief, to give people the wave tops, and then create space for them to ask questions. 

The final thing I would say is that if you're working in an area where there's no consensus or where there's confusion or disagreement, understand what that is and address it head-on. You can say to people, I know this is a space where we don't entirely agree. Here's how I come at this based on my understanding of the literature. And then make it clear that you understand where some of the landmines are. 

The last thing I would say is speak in a conversational tone. Big words are not effective at reaching broad audiences. And the more that you can speak simply and directly, the more reach you will have.