5 Ways the US Obesity Landscape Strays From the Global Picture

As obesity prevalence continues to rise, the US remains a leader in clinical research and drug development, yet it stands apart in key ways from its global counterparts.

Novotech’s “Obesity: Global Clinical Trial Landscape (2025)” report detailed how the US is a leading country in adult overweight and obesity prevalence, and how its landscape diverges from international trends in 5 important areas, from disease burden to investment patterns.¹ Since the World Health Organization (WHO) declared it a global epidemic in 1997, obesity has been on the rise. Global prevalence has doubled among adults and quadrupled among adolescents, with 1 in 8 people living with obesity in 2022.

“Obesity, once a concern primarily for high-income countries, now significantly impacts middle-income nations,” the report said. “It has surpassed the prevalence of underweight individuals across all regions except South-East Asia, driving a sharp increase in chronic diseases such as heart disease, stroke, and diabetes. Addressing obesity is now a global public health priority.”

Here are 5 ways the US obesity landscape differs from other parts of the world.

1. US Has a Higher Obesity Burden Than Most Countries

The US has some of the highest adult obesity rates in the world, with about 40% of adults living with obesity and 32% with overweight as of 2022, according to the report. These numbers far exceed those reported in other developed countries, causing the US to rank first out of 21 countries in obesity prevalence and second in overall prevalence, falling behind only Mexico with obesity and overweight rates of about 37% and 38%, respectively. Meanwhile, Germany’s adult obesity rate is 19%, France’s is 17%, and Italy’s is 10%.

It’s important to note that while most data were from 2019 or later, some countries’ prevalence rates were from as far back as 2012, which can skew some of the reports’ findings. For example, the UK’s obesity prevalence is listed as 20% in report, but this was from 2014, and 2023 data suggests this figure is now above 26%.² China, Japan, India, and Vietnam had the only single-digit obesity rates, going as low as 1.7% in 2015.¹

The elevated disease burden in the US has led to public health initiatives such as the CDC’s High Obesity Program, which funds interventions in counties where more than 40% of adults live with obesity to improve access to healthy food options and safe physical activity.

The long-term outlook is equally concerning. In a separate study, experts estimated that more than 250 million Americans could have overweight or obesity in the next 25 years.³ With the US population expected to reach 389 million by 2050, this would mean approximately 64% of Americans will fall into one of these categories, underscoring the urgency of effective prevention and treatment strategies.

2. US Leads in Early-Stage Drug Development

The US holds the global lead in early-stage obesity trials, with 258 industry-initiated obesity trials since 2019, including 109 phase 1 studies.¹ It is closely followed by Mainland China with 173 trials, 88 being phase 1, with a gap between these 2 countries and all others included in the analysis.

The global obesity clinical trial landscape has expanded rapidly in just a few years, growing from 74 unique trials in 2019 to 218 in 2024, reflecting a compound annual growth rate (CAGR) of 19.7%. Asia-Pacific and North America led this surge with CAGRs of 24.8% and 23.6%, respectively, while Europe and the rest of the world grew more modestly at 12.2% and 18.7%.

Asia-Pacific has also captured 43% of global obesity trials, outpacing North America (30%) and Europe (20%), with Mainland China and the US emerging as dominant contributors within their regions. This growth highlights a global commitment to addressing obesity through accelerated therapeutic innovation and regional diversification of trial activity.

3. US Trial Saturation Is High

Trial density, or the number of recruiting sites per million urban residents, was 6.9 in the US compared with 3.1 in Europe and 1.0 in Asia-Pacific. This suggests a more saturated and competitive research environment in the US, which can lead to longer recruitment timelines, higher site costs, and challenges in patient enrollment compared with emerging markets.

“Due to its large population and lower volume of studies, the Asia-Pacific region has lower competing trial risk with a trial density about seven times lower than that of the United States and about three times lower than that of Europe,” the report said. “This indicates a comparatively lower volume of clinical trial activity in the Asia-Pacific region signaling potential for increased research engagement.”

4. US Investment in Obesity Research and Development Outpaces Rest of the World

Between 2019 and 2024, US-based companies secured $3.4 billion in venture capital funding for obesity therapies—nearly 7 times more than China, which raised $500 million. Funding was concentrated in early-stage programs, reflecting investor confidence in long-term pipeline growth. Together, this financial backing has fueled a global pipeline of 80 drugs in preclinical development, 78 in active clinical phases, and 16 on the market.

There is also a strong focus on early– and mid-stage innovation, particularly around glucagon-like peptide-1 (GLP-1) receptor agonists. According to the report, 60% of phase 3 trials are centered on GLP-1–based therapies, while gastric inhibitory polypeptide receptor and calcitonin receptor-targeting drugs account for 10% and 7%, respectively. The remaining 23% include emerging targets, highlighting the growing diversity in therapeutic approaches to obesity management.

5. US Has More Acute Access and Affordability Challenges

Despite leading in obesity drug innovation and early-phase trial activity, the US also faces persistent challenges with access and affordability. The report noted that high treatment costs and inconsistent insurance coverage are major obstacles to widespread uptake of obesity therapies. GLP-1 receptor agonists like semaglutide and tirzepatide can cost over $1000 a month in the US, and many health plans do not include them in formularies unless patients also have diabetes.⁴

The report highlighted economic and insurance barriers as a global threat, but these challenges are especially clear in the US where out-of-pocket costs can put treatment out of reach. Without policy changes, the gap between innovation and patient access will likely continue to widen.

References

1. Obesity: global clinical trial landscape (2025). Novotech, report. April 19, 2025. Accessed May 16, 2025. https://novotech-cro.com/reports/obesity-global-clinical-trial-landscape-2025
2. Obesity profile: short statistical commentary May 2024. Office for Health Improvement & Disparities. May 8, 2024. Accessed May 16, 2025. https://www.gov.uk/government/statistics/update-to-the-obesity-profile-on-fingertips/obesity-profile-short-statistical-commentary-may-2024
3. Klein HE. Overweight, obesity to affect 64% of Americans by 2050. AJMC®. November 18, 2024. Accessed May 16, 2025. https://www.ajmc.com/view/overweight-obesity-to-affect-64-of-americans-by-2050
4. Klein HE. Rising costs lead insurers to drop weight loss drug coverage, further increasing patient burden. AJMC. August 6, 2024. Accessed May 16, 2025. https://www.ajmc.com/view/rising-costs-lead-insurers-to-drop-weight-loss-drug-coverage-further-increasing-patient-burden