DENVER, January 17, 2026 — A new approach to weight management, rolled out across a large health system in Colorado, effectively halted population-wide weight gain—a feat previously considered unattainable—and increased access to weight-related care by 23%.
A System Designed to Tackle Weight Gain at Its Source
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A novel program called PATHWEIGH is changing how primary care physicians address weight, moving beyond simple diet and exercise advice.
- PATHWEIGH, a structured process, focuses directly on weight management within primary care.
- The program, tested across 56 clinics and 274,182 patients, reduced population weight gain by 0.58 kg over 18 months.
- PATHWEIGH streamlines the process for patients to request and receive weight-related care, reducing awkward conversations.
- Experts are now considering PATHWEIGH as a potential standard of care for obesity.
For Leigh Perreault, MD, an endocrinologist, the frustration was palpable. Too often, she found herself prescribing medications to manage the symptoms of conditions like diabetes and high blood pressure, while the underlying issue—weight—remained unaddressed. “There was a moment I put my face in my hands and thought, ‘What am I doing?’” recalls Perreault, a professor of endocrinology, metabolism and diabetes at the University of Colorado Anschutz School of Medicine who practices in Westminster. “None of these people want to be on these medications and I thought if I could just help them with their weight, many of these health concerns would probably go away.”
That realization sparked the creation of PATHWEIGH, a structured system designed to integrate weight management directly into primary care. The program introduces dedicated clinic visits where providers can concentrate specifically on weight-related care, rather than squeezing it into already packed appointments.
With funding from the National Institutes of Health (NIH), PATHWEIGH was implemented across UCHealth’s 56 primary care clinics throughout Colorado. The resulting trial, encompassing 274,182 patients, stands as one of the largest randomized trials ever conducted in this field.
Published results in Nature Medicine revealed that PATHWEIGH reduced population weight gain by 0.58 kg over 18 months and, crucially, shifted the overall trend from steady gain to weight loss—an outcome with significant public health implications. “With PATHWEIGH, we showed that we absolutely eliminated population weight gain across all of our primary care, which has never been done previously,” Perreault states.
Building a ‘Highway’ to Weight Care
Perreault describes PATHWEIGH as a way to align patients and clinicians around a shared plan. “If you think about weight loss medicine or surgery or a weight loss program, those are all vehicles to weight loss,” she explains. “We built a highway that we could put all the vehicles on, so there’s actually a process for people to receive weight related care if they wanted it.”
The process began with a simple step: clinics posted signs informing patients they could request an appointment focused solely on weight management by asking at the front desk. This request automatically triggered a workflow within the electronic health record. Patients received a survey, and their responses were directly integrated into the clinician’s notes, allowing visits to focus on practical next steps rather than gathering background information.
“It made the whole process really efficient, and then effectively turned our note template into a menu of anything that we might do,” Perreault says. “It really made it extremely time efficient and consolidated everything we might do for a patient into one interface.”
Addressing Barriers and Encouraging Open Dialogue
Data collected over 18 months showed that approximately one in four eligible patients received some form of weight-related care during the trial. While lifestyle counseling was the most common intervention, prescriptions for anti-obesity medications doubled during the program’s implementation.
PATHWEIGH distinguishes itself from many one-size-fits-all weight loss programs by allowing for customized treatment plans. It also addresses the discomfort often associated with discussing weight in medical settings. “Most people who want or need weight related care never get it. Either they don’t ask for it or the providers don’t bring it up, and if they do, the patient usually gets told to go home and eat less and exercise more, and then nothing happens,” Perreault says. “The person gets frustrated and they learn to not ask for help anymore, because it’s kind of embarrassing and it doesn’t help. This was a safe space to say, ‘Hey, if you would like medical assistance with your weight, we actually have a process for you to receive that now.’”
Why Even Small Changes Can Have a Big Impact
Experts estimate that rising obesity rates are fueled by an average population weight gain of about 0.5 kg per year. Halting this increase and achieving even modest weight loss could significantly slow the obesity epidemic. “While it’s not a significant difference on an individual patient level, it’s a huge deal on a population and public health level,” Perreault emphasizes.
Researchers also found that patients who received dedicated weight-related care through PATHWEIGH experienced greater weight loss. Even those who didn’t receive direct interventions showed reduced weight gain compared to what would typically be expected.
Looking Ahead: Expanding PATHWEIGH’s Reach
Perreault notes that the program’s success has paved the way for broader adoption. Plans are underway to expand PATHWEIGH beyond Colorado. The Obesity Association, currently developing its first standards of care for obesity, is highlighting the program as a recommended care process. Five health systems across seven states are also evaluating PATHWEIGH, as its creators work toward licensing the model.
“I’m really proud that PATHWEIGH was home-grown and built and tested here in Colorado,” Perreault says. “This is the blueprint that moves us forward.”
