Endocrine Society publishes an obesity research roadmap and launches a Center on Obesity

The Endocrine Society released a new Scientific Statement on September 9, 2026, laying out what scientists know and still don't know about obesity in the era of GLP-1 medications. The document, "Obesity Science, Research Gaps, and Opportunities in the New Era of Obesity Medicines," was published online in the society's journal Endocrine Reviews and timed to the launch of the society's new Center on Obesity ^[1][2].

The statement's central argument is that improved health, not weight loss alone, should guide obesity treatment. It highlights benefits beyond the scale, including reduced risk of heart disease, sleep apnea and liver disease ^[1]. Lead author Daniel J. Drucker, MD, of Toronto, said the rapid adoption of highly effective obesity medications "has changed the treatment landscape, but important questions remain about their long-term use, individualized treatment strategies, side effects and the best ways to measure treatment outcomes" ^[1].

Six priority areas

The statement names six research priorities: the pathophysiology of obesity, with a focus on body fat regulation and "defended fat mass"; the heterogeneity of obesity and why people respond differently to treatment; redefining treatment targets beyond percent of total body weight lost; the physiology of the different phases of response to drug treatment; health outcomes with pharmacotherapy; and the safety of pharmacotherapy over the long term ^[2].

Drucker described the document as deliberately not prescriptive. "It's basically raising the key issues and questions that are important and need to be answered," he told Medscape, adding that "the answers, in many cases, have immediate clinical relevance" ^[2]. He also called for "larger, longer and more diverse studies, as well as greater use of real-world data" ^[1].

The statement treats obesity as a chronic disease requiring long-term treatment. It notes that people who stop treatment after reaching a goal weight often regain the weight and see worsening blood pressure, cholesterol and blood sugar. It also notes that studies show people can maintain much of their weight loss when they move to lower-dose therapy or switch to a different medication after the initial treatment period ^[1].

On safety, the statement flags the medications' direct effects, the consequences of rapid weight loss, and areas where long-term risks remain uncertain ^[1]. Specific concerns discussed include effects on muscle and bone, treatment timing around pregnancy, dose adjustment and ongoing monitoring ^[2].

Semaglutide, tirzepatide and other GLP-1-based therapies are now used not only for overweight and obesity but also for related conditions including heart disease, sleep apnea, and kidney and liver disease, and are being investigated for cancer, substance use disorders, arthritis and infertility, the society said ^[1].

Reactions

Obesity Society spokesperson Melissa Shoemaker, MD, of UT Southwestern, called the statement "a companion piece to existing clinical guidance," and said she valued the sections on the limits of BMI and percent weight loss as sole measures of success, the question of an optimal rate of weight loss, and dose adjustment ^[2].

Juliana S. Simonetti, MD, of the University of Utah, called it "a great paper for learning the science behind the physiology" but said she would have liked more specific discussion of racial and ethnic differences, noting that "much lower amounts of fat tissue can lead to much higher rates of obesity-related medical complications" in some populations ^[2].

Drucker has served as a speaker in the past 12 months for Novo Nordisk and Eli Lilly and as a consultant to a long list of drug companies, including AstraZeneca, Amgen, Merck, Pfizer, Roche and Sanofi ^[2].

Why it matters for patients

This is a research agenda, not a set of treatment rules, so nothing about prescribing or coverage changes today. But it signals where the field is heading. If "success" is redefined to include sleep apnea, liver disease and cardiovascular risk rather than a percentage on the scale, future trials, guidelines and possibly insurer criteria may be written around those broader measures.

The statement also puts official weight behind several things patients already experience: that response to these drugs varies a lot from person to person, that weight loss slows and plateaus, and that stopping treatment commonly leads to regain and worsening of blood pressure, cholesterol and blood sugar ^[1][2]. It acknowledges that questions about muscle and bone, pregnancy timing and long-term safety are still open rather than settled ^[2].

What happens next

Amy E. Rothberg, MD, who chaired the task force that developed the Center on Obesity, said the society is updating its clinical practice guideline on obesity medications and expects to publish it in January 2027 ^[2]. That guideline, unlike this statement, is the document that typically shapes day-to-day clinical practice. The society said the Center will curate obesity research from its journals and support advocacy on research funding and access to care ^[2].