Get the Right Care
Community Involvement
Obesity in a Changing Medical Landscape
Obesity has long been recognized as a major contributor to over 200 chronic diseases spanning nearly every organ system such as type 2 diabetes and prediabetes, and heart disease. What is changing, however, is both how obesity is defined and how effectively it can now be treated. This shift has public health implications, but its most direct impact is on people living with obesity.
For many years, people experiencing obesity have been diagnosed primarily using body mass index (BMI), a simple calculation based on a person’s height and weight. While BMI is easy to use, it does not directly measure body fat or show where fat is distributed in the body, details that are closely linked to health risks. For example, excess abdominal fat can contribute to cardiometabolic risk even in someone without a high BMI.
In January 2025, an international commission of medical experts published recommendations in The Lancet Diabetes & Endocrinology. The medical experts proposed distinguishing obesity and clinical obesity. According to this new suggested terminology, obesity means having excess adiposity, rather than just increased BMI, and clinical obesity is a chronic disease in which increased adiposity impairs health. Under this approach, additional measures such as waist circumference or waist-to-height ratio are used to help assess people at risk.
The framework also distinguishes clinical obesity from preclinical obesity, in which excess adiposity is present but organ function is preserved and there are no meaningful physical limitations in daily life. This distinction gives healthcare professionals a more complete understanding of how increased adiposity impacts an individual's health and functioning, and can inform more appropriate obesity care and prevention strategies.
When these broader criteria are applied, obesity becomes far more common than when BMI is used alone to measure obesity. A large study of 301,026 US adults published in JAMA Network Open found that 42.9% of participants met traditional BMI-based definitions of obesity. When the newer criteria for excess adiposity were used, that figure rose to 68.6% of individuals who were found to be obese.
Many individuals newly classified as having obesity had adipose tissue deposition patterns associated with higher cardiometabolic risk, despite not meeting the traditional BMI definition. Participants with anthropometric-only obesity (meaning obesity defined solely on the basis of anthropometric measures such as BMI or waist circumference) had higher odds of organ dysfunction and elevated risks of diabetes, cardiovascular events and all-cause mortality compared with participants without obesity. These findings show associations and do not prove causation.
Separate research by Ahmed and colleagues involved 471,228 adults across 91 countries. The analysis revealed that 21.7% of participants with a normal BMI had abdominal obesity. These patients with increased adiposity had a higher chance of having hypertension, diabetes and adverse metabolic findings. This evidence reinforces the limitations of using BMI alone.
While obesity is being more widely recognized, treatment options have advanced significantly. Medications known as GLP-1 receptor agonists, particularly semaglutide, have demonstrated substantial and sustained weight loss during active treatment in large clinical trials.
In the STEP 1 trial, part of the Semaglutide Treatment Effect in People with Obesity program, adults without diabetes lost an average of about 15% of their starting body weight when treated with once-weekly semaglutide 2.4 mg alongside lifestyle counselling for 68 weeks. The placebo group lost an average of 2.4%. These results were once considered achievable mainly through bariatric surgery.
Medication is not suitable for every patient, and results vary. Medical assessment and ongoing support are essential to ensure that treatment is appropriate. Bariatric surgery remains an established option for eligible patients, particularly when obesity is severe or associated with significant health complications.
Together, these changes mark a turning point. More people may now be recognized as having obesity, but obesity is also becoming increasingly treatable. Much like high blood pressure, it is emerging as a common, measurable condition for which effective long-term therapies are available.
Clinique Michel Gagner in Montreal, Canada, provides individualized obesity management, including specialist consultations, nutrition consultations with dietitians and GLP-1 treatment when clinically appropriate. The clinic also offers bariatric and endoscopic weight-loss procedures for eligible patients.
Choosing between these options can be challenging. The focus of a clinical assessment is to determine which treatments warrant consideration based on the individual’s health, expected benefits and potential risks. Prospective patients can review the clinic’s treatment fees or complete the patient questionnaire to begin the assessment process.
1. Lancet Diabetes & Endocrinology Commission. Definition and diagnostic criteria for clinical obesity. The Lancet Diabetes & Endocrinology, 2025.
2. Ahmed, K. Y., et al. Cardiometabolic outcomes among adults with abdominal obesity and normal body mass index. JAMA Network Open, 2025.
3. Wilding, J. P. H., et al. Once‑weekly semaglutide in adults with overweight or obesity. New England Journal of Medicine, 2021.
