This spring, Toronto endocrinologist Dr. Daniel Drucker was awarded the prestigious Breakthrough Prize in Life Sciences — the “Oscars of science” — for a discovery he made nearly four decades ago. While working in a Boston lab in the 1980s, Drucker helped unravel the therapeutic potential of GLP-1, a gut hormone involved in blood sugar regulation. Ten years later, he built on that research by demonstrating how this naturally occurring peptide could also suppress appetite, laying the groundwork for a class of drugs that are now reshaping weight management and obesity treatment.
Originally developed to treat Type 2 diabetes, GLP-1 receptor agonists or GLP-1 RAs — better known by such brand names as Ozempic, Wegovy and Mounjaro — have become widely known for their use in weight loss. In 2023 alone, 7.1 million prescriptions were dispensed in Canada. However, while GLP-1 RAs are a powerful tool, they’re not meant to be taken in isolation. In 2020, Obesity Canada and the Canadian Association of Bariatric Physicians and Surgeons developed a set of patient-centred, experience-based best practices designed to guide health-care providers in delivering obesity care. These guidelines emphasize that effective obesity treatment should include medical nutrition therapy (essentially, a personalized dietary plan created by a registered dietitian), physical activity, psychological interventions and other behavioural adaptations. Yet the reality of obesity care, and health care in general, presents challenges that leave many patients without adequate support.
“Patients come to see us for the medication. And the issue is, as doctors, we don’t have the time — or expertise, necessarily — to talk about everything else,” says Dr. Dimitre Ranev, a family physician who practices in both Ottawa and Gatineau. Fewer than five per cent of U.S. patients on GLP-1 RAs receive any kind of behavioural or lifestyle therapy, and this lack of support undermines treatment: A 2024 study by Blue Cross Blue Shield found that 30 per cent of patients who were prescribed GLP-1 RAs stopped taking them within the first month, and only 42 per cent were still on the medications at the 12-week mark.
“We still struggle with the delivery of basic care around obesity,” says Dr. Puneet Seth, the Toronto physician and entrepreneur behind Nymble, an AI-powered support platform trained on a proprietary knowledge base. Launched last year, Nymble provides structured ongoing support via text-based messaging.
The tool helps patients anticipate and manage side effects including nausea, constipation and fatigue — a major barrier to adherence — by offering timely tips about what to expect, dose adjustment guidance and check-in messages, says Seth. It also helps users integrate behavioural changes, such as adjusting meal sizes and building consistent movement into their routines, as well as prepare questions for followup appointments. Nymble even scans social media platforms to assess what comments influencers are making about obesity management, with the aim of helping dispel misinformation.
Ranev has used Nymble in his practice for a few months. While the tool is not a replacement for an actual therapist or a doctor, he says, it provides in-between support that’s “available all the time. And that’s important.” Nymble is already expanding beyond Canadian clinics through a new partnership with Shoppers Drug Mart and an evidence-based obesity management practice in Ireland, suggesting broadening interest in patient-centred support that meets people where they are.
Obesity care has also been hindered by an overreliance on body-mass index as a diagnostic tool. Originally established in 1832 by a Belgian astronomer, BMI was introduced to the mainstream in the 1970s by an American physiologist as a convenient metric for studying weight at a population level. But when it comes to evaluating an individual’s health, it’s far too crude a measure, according to Dr. Jean-Pierre Després, a leading researcher with Université Laval who has been studying metabolic health since the ’80s.
One of the biggest shortcomings of BMI is that it doesn’t account for fat distribution, which is often a stronger predictor of health risks than overall body weight. Critically, BMI fails to measure visceral adipose tissue (VAT), also known as abdominal obesity, a harmful type of fat that surrounds and infiltrates internal organs. According to Statistics Canada, 43 per cent of Canadians have VAT. “This ‘hidden fat’ is a lot more dangerous to your health than excess body weight,” explains Després. Subcutaneous fat (the kind that sits just beneath the skin) is largely inert. VAT, on the other hand, is metabolically active, and releases hormones and substances that can wreak havoc on the body’s internal systems, promoting systemic inflammation and insulin resistance, damaging blood vessels, contributing to the buildup of artery-clogging plaque and increasing the risk of heart attacks and strokes.
Although GLP-1 RAs can be effective in reducing VAT, they’re prescribed primarily based on BMI thresholds — which means someone with elevated VAT whose BMI falls in the “normal” range won’t qualify for pharmacological intervention, despite facing potential metabolic risks. (Conversely, someone with a high BMI but low VAT may not have any metabolic issues at all.) This disconnect is especially baffling given that GLP-1 RAs have long been used to treat and reduce the risk of Type 2 diabetes and cardiovascular disease. Després believes there’s likely a link between those clinical benefits and a reduction in patients’ VAT. “But we don’t have that evidence because, as of now, the only end point reported in the clinical trials is weight loss,” he says.
This highlights a fundamental problem in the conventional framing of obesity treatment: weight loss, rather than metabolic improvement, is presented as the goal. Physicians are also conditioned to see the number on the scale as the outcome, overlooking the more meaningful markers — insulin sensitivity, inflammation levels and cardiovascular function — which more accurately reflect a person’s risk of chronic diseases such as Type 2 diabetes and heart disease.
Understanding GLP-1 RAs as metabolic health tools rather than diet drugs could help shift the focus. Nymble tries to avoid focusing solely on weight by integrating various domains, including behavioural therapy, nutrition and physical activity, the science of appetite and how therapeutics work. “We won’t see the net benefit of these medications until we address obesity as a complex chronic disease,” says Seth.
Dr. Dan Drucker and Dr. Puneet Seth are speaking at the MaRS Impact Health conference on May 7 & 8. Check out the full program here.
Caitlin Walsh Miller writes about technology for MaRS. Torstar, the parent company of the Toronto Star, has partnered with MaRS to highlight innovation in Canadian companies.
