The growing crisis of obesity in the US

This transcript has been lightly edited for clarity

Rhonda Stewart: Welcome to Global Health Insights, a podcast from IHME, the Institute for Health Metrics and Evaluation. I’m Rhonda Stewart. In this episode, we’ll hear from IHME Affiliate Associate Professor Marie Ng as she discusses the most comprehensive national-level study of obesity and overweight in the United States.

Across all states and age groups, researchers found startling increases that require immediate action given both current and future trends for adults, adolescents, and children. The study looks at what’s driving rising rates of obesity and overweight in adults and young people, how new GLP-1 weight loss drugs may have an impact, and what it will take to address these trends.

The total number of US children and adolescents with overweight and obesity is expected to reach 43.1 million by 2050, and the number of overweight or obese adults will climb to 213 million.
Some states are impacted more than others, but as Professor Ng notes, every state is facing this challenge to some degree and obesity is at a crisis point throughout the US. The research is part of a new series on health and health policy in the US that will be published in The Lancet.

The results of the study are quite striking. You and the other researchers note that without immediate action in the US, 213 million adults over the age of 25 and more than 43 million children and adolescents between the ages of 5 and 24 are expected to have overweight or obesity by 2050.
These changes will bring significant health, social, and economic consequences, of course. Let’s talk about the health consequences first. What are some of the health conditions that that can be triggered by overweight and obesity?

Marie Ng: At the individual level, overweight and obesity increase the risk of diabetes, cardiovascular diseases, and certain cancers. We are also seeing shortening of life expectancy – US life expectancy is actually trailing behind its high-income counterparts. If you recall, during COVID, patients with obesity also were disproportionately affected, with higher mortality rates. The health consequences are pretty profound. It’s not just non-communicable diseases like the ones that we typically mention, like heart disease, but it also can affect infectious disease as well.

Rhonda Stewart: The paper also details geographic differences in overweight and obesity and differences between men and women as well. Tell us about some of those findings.

Marie Ng: So basically, one of the key messages is that no state is spared from this obesity crisis. So we see southern states such as Oklahoma, Alabama, Arkansas, Mississippi, Texas – they continue to have relatively higher levels of overweight and obesity. For example, we see over half of the older adolescent boys in Texas and nearly two-thirds of older adolescent girls in Mississippi are living with overweight and obesity. And this trend is continuing to 2050, and similarly in adults: adult overweight and obesity are also higher in southern states. But we want to emphasize that even for states, for example Colorado, where obesity and overweight prevalence is lower, we still see substantial increase over the past 30 years, and it’s going to continue to increase in the next 30 years.

Rhonda Stewart: And what about some of the differences between men and women?

Marie Ng: We saw women, particularly children and adolescent girls tend to have higher obesity and overweight prevalence, and this is likely due to some of the physiological differences. But this trend continues into adulthood. In adulthood we do see a slight reverse, where men tend to experience higher rates of overweight and obesity than females, which is pretty common in high-income countries.

Rhonda Stewart: The study traces how rates of obesity have changed over time, with women, for example, experiencing the onset of obesity at earlier ages. What accounts for some of those types of changes?

Marie Ng: Adolescent girls tend to experience puberty fat mass differences compared to boys, where essentially adolescent girls will have fat deposits. You can think of it as in preparation for future pregnancy – this is a physiological difference. On the other hand, there are also studies that mention that early sexual maturation is associated with obesity as well. This might be due to the changes in current modern diets and also differences in physical activities in modern days. So we do observe that early onset in girls in adolescence.

Rhonda Stewart: The study does paint a stark picture of obesity and overweight for young people. So tell us a little bit more about some of the drivers for children and adolescents. You mentioned puberty, for example. What are some of the other factors contributing to overweight and obesity in children and adolescents?

Marie Ng: Lifestyle factors definitely play a huge role. So for example, high calorie intake and low physical activity. And some of these lifestyle changes are actually driven by structural factors. So for example, children these days don’t walk to school as much, and so they have lower physical activity. And also in terms of this very, very aggressive marketing of unhealthy food by the food industry. And so in general, it is not just about the individual lifestyle, but also structural factors that are prohibiting the adoption of a healthy lifestyle.

Rhonda Stewart: What are some of the social and economic impacts of obesity and overweight? We’ve been talking about the health impacts. What are some of the social and economic impacts of obesity and overweight?

Marie Ng: The management and treatment of obesity will put substantial pressure on the existing health care system, which is already strained, and the economic impact is very profound. At a societal level, the treatment and management of obesity is going to put substantial pressure on the existing health care system. The economic impact is also very profound. The Joint Economic Committee report earlier this year predicted that in the next 10 years the health care costs related to obesity are going to rise to $9.1 trillion. This is not a small number, of course, in terms of the social impact. There’s also the consideration of perception of obesity and stigma. These are some of the social factors that that need to be considered as we are talking about obesity.

Rhonda Stewart: There’s also been quite a bit of discussion recently about GLP-1 weight loss drugs. How do those fit into the picture?

Marie Ng: I think GLP-1 and all the anti-obesity medications or therapeutic treatments will still be an important part to tackle this obesity crisis. However, there are substantial uncertainties. For example, our understanding of the long-term effects of GLP-1 is still quite limited, and most of these drugs are not approved for children and adolescents yet. Not to mention the cost – the current cost of GLP-1 is very expensive, although the market exclusivity is coming to an end. So it depends on the negotiation. Unless prices come down substantially, this is unlikely going to be a widespread intervention.

Rhonda Stewart: And speaking of interventions, let’s talk about those. What role does policy action play in addressing rising rates of obesity and overweight?

Marie Ng: Yeah, policy is going to play a substantial role because a lot of the obesity crisis is driven by structural drivers such as aggressive food marketing by the food industry. We’re talking about urban planning that does not take into consideration safe space for physical activities. So those will need to come at the policy level. But it will be very important to emphasize that any policy interventions need to be guided by science and driven by data – it’ll be very important for policymakers to take into consideration the latest scientific evidence as they are designing policy and interventions.

Rhonda Stewart: And what’s the main thing that people should take away from this study? Certainly we’ve been hearing for many years in the US in particular about the rise of obesity and overweight.
So what is the most important thing that people should keep in mind with this new research?

Marie Ng: It is very important to be aware of the rising crisis and still be very conscious of this risk. At the individual level, there are lifestyle and behavioral changes that one can adopt. But understanding that there are also a lot of environmental structural factors that makes it difficult. So really at the governmental level, government at the state, local, and federal levels really needs to step up in terms of strengthening policy and really providing the support to enable individuals to adopt healthy lifestyles.

Rhonda Stewart: Great. Thanks so much.

Marie Ng: Thanks.

Rhonda Stewart: Details on the new obesity study can be found at www.healthdata.org.