Two figures serve to concentrate the mind of public health policy makers when planning to address Obesity- $3trn, the projected annual economic cost of obesity globally by 2030 (both medical and lost productivity costs) and $100-200bn, the IQVIA forecast range for the value of the sales of modern Anti-Obesity Medications globally by 2030¹.

It is clear that both the economic costs of obesity, and the costs of the serious health consequences for people living with obesity for healthcare systems and economies are unsustainable, even as healthcare payers struggle to plan budgets for the unquestionably effective new Anti-Obesity Medications (AOMs) which are not only showing unprecedented performance in weight loss, but also, increasingly, clinically proven benefits in obesity related conditions such as cardiovascular disease risk, chronic kidney disease, obstructive sleep apnoea, and non-alcoholic fatty liver disease.

The best possible Real World Evidence and insight is the critical ingredient for healthcare providers, healthcare systems and policymakers to chart a path balancing accessing the health and economic benefits of health system investment in the new AOMs with limited budgets and competing priorities. This blog looks at the case for investing in the collection of Real World Data at the start of planning for public health provision of AOMs and the value that registries can provide in delivering this strategy.

Why use of Anti-Obesity Medications needs Real World Data, and why Registries can power optimal insight development

Obesity is a global issue affecting all countries, and it is growing in prevalence at a frightening rate. Already, 1bn people worldwide live with a Body Mass Index (BMI) of 30 or greater, and that number is forecast to grow, unless there is high impact intervention, to 2bn by 2035². Public health initiatives to prevent obesity, focusing on diet, exercise and taxing or restricting unhealthy foods have been implemented for decades, and whilst undoubtedly having value they have been unable to turn the growing tide of obesity. AOMs offer the possibility of a new and potentially powerful tool, but healthcare providers must understand how to use it.

The current wave of anti-obesity medications is still relatively new. Wegovy, or semaglutide for obesity, was first approved in 2021 and tirzepatide, known as Mounjaro or Zepbound for obesity, in 2023. These are the first truly effective prescription obesity treatments capable of driving weight loss close to bariatric surgery, the previous gold standard treatment.

Often, policy makers in health systems have not recognised obesity as a chronic, serious but treatable disease, but this is changing, with the Lancet Commission on Obesity definition of clinical obesity³, and the American Society of Metabolic and Bariatric Surgery⁴ consensus statement. The Lancet Global Commission published findings at the beginning of this year after five years of work⁵. Global clinical experts in obesity stated two things: obesity is a chronic, treatable disease with serious health consequences. They distinguish between preclinical obesity (weight) and obesity as standalone diseases with comorbidities.

The direction of travel for healthcare policy is to treat obesity as a serious and chronic condition for which effective pharmacotherapy should be considered a treatment option, and the measurement of which should evolve to more complex collection of measures often currently unrecorded.

In the US, health insurance plans, Medicare and Medicaid cover AOMs to a variable extent and with caveats, but extensive coverage has been achieved. Outside the US, there’s growing moves towards reimbursing AOMs. As of mid-2025 the UK, Israel, Japan, and Switzerland reimburse them, and other European countries might follow suit soon. Patients aren't waiting; they're paying out-of-pocket for these medications. In the UK, for example, 1.5 million people, and hundreds of thousands across the Germany, the Nordics and elsewhere are paying for prescriptions themselves as of mid-2025.

As obesity becomes a treatable area, it also grows more complex. There are patient segmentations driven based on comorbidities and needs. Moving insights beyond clinical data is crucial, as clinical trials, though large, don't necessarily reflect real-world populations, especially outside the U.S.. Clinical trials can't capture long-term obesity treatment, which requires tracking patients over years, necessitating registries and real-world data. Most patients with a BMI over 30, the threshold for obesity, have one or more comorbidities, which increase rapidly with higher BMI. The Lancet Commission recommended moving beyond BMI, which is under-collected in many healthcare systems, to more complex definitions like waist to height ratio (although it should be noted, the US regulator, the FDA, still focuses on BMI) and organ dysfunction, more complex measures most collectible in depth via registries.

Although the private market for obesity agents has grown faster than the public market, governments will inevitably have to include these agents in public coverage where health systems have public coverage of reimbursed medications. Healthcare policy makers must grapple with the need for real world data and registries to address key policy issues related to obesity. Healthcare systems use of AOMs requires innovative thinking about investment, infrastructure and delivery, addressing very rapid evolution, necessitating a public health approach to obesity management informed by real-world data and obesity registries. There may also be a role for both Real World data collection and Registries within patient funded prescription AOM use, both because this is where the majority of real world use currently is and also because this will continue to be the case, with use of innovative channels for delivery which could have interest and lessons for publicly funded prescription AOM provision.

Real-world data studies have shown the exciting potential of obesity agents in reducing risk factors across various serious comorbidities. Here's an example of a large U.S. real-world study on veterans. This observational study on U.S. veterans with diabetes, skewed towards older white males, involved 2 million people, with 200,000 diabetics on GLP for diabetes. GLPs are also used for obesity treatment. Veterans on GLP had reduced risks in 42 conditions, including heart disease, renal disease, Alzheimer's, psychotic disorders, certain cancers, and substance abuse disorders. There was increased risk in GI disorders, syncope, and joint pain. This suggests broad health benefits of these agents, reducing risks of serious conditions that burden healthcare systems and have economic impacts. Understanding this in broader populations requires real-world data and registries.

In a blog published by IQVIA⁶, we compared obesity clinical trial populations for the seven largest, by patient numbers, clinical trials so far published in obesity, each of which included at least 1,000 subjects, to the U.S. real obese population. Despite being the largest market, most trials don't reflect the U.S. obese population. Of the seven largest obesity clinical trials for current market agents, only one reflects the gender balance of the U.S. obese population. Others overrepresented men or women. Three trials had average ages much higher than the true U.S. obese population, sometimes by almost 20 years. African Americans were underrepresented, while Asian Americans were overrepresented compared to their true representation in the U.S. obese population.

This is just the U.S., in European countries, differences between real obese populations and trial populations are likely larger. This highlights the need for real-world data across all countries.

In making the case for the importance of real-world data generation in obesity, we also need to move beyond the constraints of existing data collection. Key measures of obesity levels in populations include BMI, and more recently waist to height ratio, but the collection of both varies considerably between and within countries. A retrospective study of 989, 955 patients aged ≥18 years who visited their GP in 2023 using data from the IQVIA Disease Analyzer database in Germany found that BMI documentation was recorded for only 10.8% of the patients⁷.

Whilst BMI records are better in other countries than this German example, the assessment of individuals living with obesity is evolving. Increasingly, more advanced methods than BMI alone are being used to determine appropriate pharmacological treatments and to evaluate their effectiveness. Data collection needs to improve both on the basics while evolving rapidly.

The cost-benefit equation, with obesity costs at $3trn globally by 2030 versus obesity agent spending at 100-200 billion globally, argues for bold investment. However, payers will ask how to target obesity spending, the time horizon for impact, where savings can be realized, and how to make the case for investment. Real-world data and registries will play a critical role.

We've seen significant use of these agents in the private sphere, but this is inequitable as it benefits wealthier individuals who can afford them. Policymakers will face pressure to ensure equitable access to these agents, and real-world data will drive equitable access.

Additionally, there are over 170 obesity agents in the pipeline, from phase one to clinical trials. Soon, we'll have oral obesity agents (from 2026) and non-GLP obesity agents. Healthcare providers will need to make decisions in a complex pharmacotherapy environment over the next decade, informed by the best data, to build a sustainable approach to accessing the best obesity pharmacotherapy and using it cost-effectively with the highest return on investment.

What are registries and how can they be used in the Obesity field?

Registries, used to collect a range of data on a group of patients often with a particular condition, are used in many types research and quality improvement programs. Their application to the field of obesity is promising for a number of reasons:

• Existing databases which contain data about people living with obesity are often siloed and don’t represent the full spectrum of populations with obesity
• The multisystem impact of obesity, both clinically and economically, means that the full breadth and depth of different data types is often not present at a single site, or site network, and often requires capture of data from people living with obesity themselves
• Real World Evidence in this field will require longitudinal tracking and monitoring of outcomes across a range of care settings and Healthcare Professional specialties - including interactions with non-traditional healthcare settings and digital / remote providers
• Given the impact of living with obesity on people’s life and life experiences, and the need to address the needs of the individual holistically, as discussed in IQVIA’s recent indepth patient insight study⁸, we need to collect patient experience data using validated ePROs and surveys. Registries are an ideal way to collect this important data.

When we use the term 'registry,' it can have narrow or broad definition, covering various use cases, from product-centric research on specific obesity populations, to large-scale population health or public health surveillance programs. Registries can be created and used by many different stakeholders to collect Real World data and evidence for a range of uses, including:

• By healthcare providers and healthcare professionals to enable implementation of treatment recommendations and development and quality improvement of programmes,
• Governments and public health agencies to make and evaluate obesity prevention and treatment policy
• Life science and Med-tech innovators to understand natural history of disease, outcomes for pharmacotherapies and medical devices

Registries can, therefore, be used for a range of different medical purposes, from diagnosis, treatment and monitoring of a condition and the outcomes of treatment of that condition, to development of healthcare policies, as well as the planning and evaluation of healthcare services. All are relevant to health system planning for the fast-developing field of obesity. We're seeing both new organizations and existing ones take an interest in obesity due to its broader complications and intersections with a broad range of disease areas, some covered by existing registries. Health authorities, and policy makers are interested in sustainable healthcare models, adapting care pathways, impact modelling, and getting value for money in obesity. They're keen on data collection initiatives to support these programs.

Obesity registries have been created across multiple countries since the early 2000s . Many examples, like the Swedish Childhood Obesity Treatment Registry and the Electronic Registry for the Management of Childhood Obesity in Greece, or the National Collaborative on Childhood Obesity Research in the U.S., are focused on childhood or adolescent obesity, an important area of obesity management research and data recording, but there remains a paucity of obesity registries which address adult populations, and perhaps one which reflect the very rapid changes in the nature of the treated population of people living with obesity and reflects their lived experience of the management of their weight loss, and the range of data collectable from resources which could include wearable devices and digital support programmes.

As IQVIA depth patient insight research shows, people living with obesity have complex journeys towards engagement with healthcare systems and treatment, ones which have been all too often characterised in the past by disconnection and denial of care¹⁰. Obesity patients touch various health system aspects across primary, secondary, and tertiary care, with numerous comorbidities and downstream outcomes. Data collection is challenging, requiring expertise and diverse tools, but the technologies which underpin data collection are rapidly evolving, as is the interoperability landscape, and access to advanced analytic and AI-based tools for data processing and use, which can make registries more cost and time efficient to implement and run.¹¹

Therefore, ensuring that a planned obesity registry adopts the right technology based on the circumstances is a critical first step. Registry solutions can be optimized for care management and fully integrated into care delivery systems. Other approaches can be designed for lightweight, lower complexity, remote, and direct-to-patient data collection. Ultimately, the goal is to bring the right technology and partnerships for the goals of a given registry.

Real World Data collection, and Obesity Registries have the potential to play a critically important role in the development of policy, evaluation and impact for this new phase in the evolution of obesity prevention and treatment. Healthcare policy makers, providers, both public and private and payers should consider how to plan for Real World Data collection and consider the use of Registries to facilitate this in their policy planning for the next phase of this very fast moving area. The time to plan is now.

To find out more about IQVIA’s registry experience and capabilities visit our dedicated webpage: https://www.iqvia.com/solutions/real-world-evidence/study-design/patient-registries