What do Canada’s obesity guidelines say about BMI, waist size and medicines?
The Canadian guideline’s definition of obesity, its BMI and waist cut-offs, the lower thresholds for Asian adults, the Edmonton staging system, and where medicines come in.
Written for Canada. Other country versions are coming.
Obesity Canada’s guideline calls obesity a chronic disease, judged by its effect on health, not by BMI alone. It discusses medicines at a BMI of 30 or more, or 27 or more with weight-related health problems, using lower cut-offs for some groups. For South, Southeast and East Asian adults, overweight starts at a BMI of 23.
Key takeaways
- Obesity Canada defines obesity as a chronic, relapsing disease in which excess body fat impairs health, and says screening should use both BMI and waist size.1
- The guideline says medicines should be offered at a BMI of 30 or more, or 27 or more with weight-related health problems, using ethnicity-specific cut-offs where they apply.2
- For adults of South, Southeast or East Asian ethnicity, the guideline puts the start of overweight at a BMI of 23, not 25.1
- In Canada, a waist of 102 cm (40.2 in) or more in men or 88 cm (34.6 in) in women signals higher risk; Asian cut-offs are 85 cm and 75 cm.1
- The guideline says weight-loss medicines bring weight back and health benefits fade when they are stopped, so they are meant for long-term use.2
On this page
- What is Canada’s obesity guideline?
- How does the guideline use BMI?
- What waist size does the guideline use?
- Why are the cut-offs lower for Asian adults?
- What is the Edmonton Obesity Staging System?
- When does the guideline discuss medicines?
- Do public drug plans use the same thresholds?
- Questions people ask
- How we researched this
What is Canada’s obesity guideline?
It’s the Canadian Adult Obesity Clinical Practice Guideline, published by Obesity Canada as a “living document” whose chapters are updated one at a time.2
- GLP‑1 medicines are prescription-only in Canada.3
- Guideline thresholds are points for a conversation with a prescriber. They don’t mean anyone qualifies for, or should take, a medicine.
- Every risk of these medicines is in Guide 5: Side effects and risks.
- Assessment chapter (version 1, August 2020): how to measure and stage obesity.1
- Medicines chapter (version 3, 11 August 2025): when medicines are offered, and which ones.2
How it defines obesity. “A chronic, progressive and relapsing disease, characterized by the presence of abnormal or excess adiposity that impairs health and social wellbeing.” Adiposity means body fat.1
The medicines chapter says the goal is better health, “not solely weight reduction”, including outcomes that matter to the person.2
How does the guideline use BMI?
As a quick first screen only. A BMI of 30 or more identifies obesity in most adults, and Health Canada recommends that obesity not be diagnosed by BMI alone.1
BMI (body mass index) is your weight in kilograms divided by your height in metres, squared.1 For someone 1.70 m (5 ft 7 in) tall who weighs 90 kg (198 lb), that’s 90 ÷ (1.70 × 1.70) = 31.1. This is our arithmetic.
| Category | Most adults | South, Southeast or East Asian adults |
|---|---|---|
| Healthy weight | 18.5–24.9 | 18.5–22.9 |
| Overweight | 25–29.9 | 23–24.9 (at risk); 25–29.9 (moderate risk) |
| Obesity, or highest risk | 30 or more (classes 1 to 5) | 30 or more (“severe risk”) |
Obesity Canada assessment chapter, Table 1, checked 12 Oct 2026.1
Where BMI misleads. The guideline lists its limits:1
- It doesn’t measure body fat, heart risk or health directly.
- It overestimates fat in muscular people and underestimates it after muscle loss.
- It over- or underestimates fat in some groups, “such as Indigenous Peoples, South Asians, Chinese and other populations”.
What waist size does the guideline use?
In Canada, 102 cm (40.2 in) or more for men and 88 cm (34.6 in) or more for women signals higher risk. For South, Southeast or East Asian adults the cut-offs are 85 cm (33.5 in) and 75 cm (29.5 in).1
Waist size is a stand-in for fat around the organs (visceral fat), which is linked to heart and metabolic disease.1 The guideline suggests measuring it in adults with a BMI of 25 to 35.1
The 2025 medicines chapter goes further. It asks prescribers to use waist size, waist-to-hip or waist-to-height ratio alongside ethnicity-specific BMI or weight-related health problems when deciding about medicines.2 The inch figures are our conversions.
Uses the Canadian cut-offs, including the Asian ones. Nothing is stored. No sign-up.
Why are the cut-offs lower for Asian adults?
Because health risks rise at a lower BMI. In an Ontario study, South Asian adults had the diabetes risk of a white BMI of 30 at a BMI of 24.4
The study followed 59,824 Ontario adults aged 30 and over who didn’t have diabetes at the start, for up to 12.8 years.4 A McMaster University study of 1,078 people in four Canadian regions found the obesity cut-off, judged by blood sugar and blood fats, was about 6 BMI points lower in South Asian, Chinese and Aboriginal adults than in Europeans.5
Our post on South Asian Canadians and GLP‑1s goes deeper. The weight and health guide walks through measuring your waist.
What is the Edmonton Obesity Staging System?
It grades obesity from stage 0 to 4 by its effect on health, not by size. The guideline suggests using it to judge severity and guide treatment.1
- Stage 0: no weight-related risk factors, symptoms or limits on daily life.1
- Stage 1: early risk factors, such as borderline blood pressure or blood sugar, or mild symptoms.1
- Stage 2: an established weight-related disease, such as high blood pressure, type 2 diabetes or sleep apnea.1
- Stage 3: established organ damage, such as a heart attack or heart failure.1
- Stage 4: severe, potentially end-stage disability from weight-related disease.1
The guideline says that in population studies the staging predicted death from any cause better than BMI or waist size alone.1
When does the guideline discuss medicines?
At a BMI of 30 or more, or 27 or more with weight-related health problems, adjusted for ethnicity, and always alongside changes to eating and activity.2
The guideline names six medicines approved in Canada for long-term weight management: liraglutide (Saxenda), naltrexone/bupropion (Contrave), orlistat (Xenical), semaglutide (Wegovy), tirzepatide (Zepbound) and setmelanotide (Imcivree).2 It says the choice should fit the person’s values, goals and costs.2
The labels say much the same. Wegovy and Zepbound are approved for adults with a BMI of 30 or more, or 27 or more with a weight-related condition.6,7 Saxenda’s label adds, for the 27 to 30 group, that a previous weight-management attempt has failed.8 Ozempic and Mounjaro are approved for type 2 diabetes, not weight loss.9,10
Long term. The guideline says trials “consistently demonstrate weight regain and regression of health improvements when treatment is stopped”.2 It has no fixed 5% stopping rule, because health can improve with modest weight loss.2
- Stomach effects are the most common. On the Wegovy label, 44 in 100 people felt sick (nausea), against 16 in 100 on a dummy injection.6
- Dehydration from vomiting or diarrhea can harm the kidneys, the Zepbound label warns.7
- Inflamed pancreas (pancreatitis): severe stomach pain that won’t go away needs medical help straight away.6
- Gallstones: 1.6 in 100 people on Wegovy, against 0.7 in 100 on a dummy injection.6
- Not for everyone: not with a personal or family history of medullary thyroid cancer or MEN 2 (a rare inherited condition), and stopped at least 2 months before a planned pregnancy.6
Do public drug plans use the same thresholds?
No, they’re narrower. Canada’s Drug Agency recommended public funding of Wegovy only for adults with a BMI of 27 or more and established heart disease.11
- Wegovy: renewal after the first year would need at least a 5% drop in BMI or body weight.11 Price talks ended without agreement in December 2025, and BC lists it as a non-benefit.12
- Zepbound: the agency recommended funding for adults with a BMI of 27 or more and prediabetes, with conditions, again needing a 5% drop to renew.13
A recommendation isn’t coverage: each province decides. Our post on why no province covers Wegovy or Zepbound explains the steps.
Questions people ask
What BMI is obese in Canada?
Obesity Canada’s table puts obesity at a BMI of 30 or more for most adults, with lower risk cut-offs for South, Southeast and East Asian adults.1
What BMI do you need for Wegovy in Canada?
The Canadian label covers adults with a BMI of 30 or more, or 27 or more with a weight-related condition.6 A prescriber decides; public plans don’t cover it for weight.12
What waist size is too big in Canada?
The guideline uses 102 cm (40.2 in) for men and 88 cm (34.6 in) for women, or 85 cm and 75 cm for South, Southeast and East Asian adults.1
Does the guideline say to stop if you lose less than 5%?
No fixed rule. It says health can improve regardless of how much weight is lost.2 Public funding recommendations do use a 5% test at one year.11,13
Is obesity a disease in Canada’s guideline?
Yes. It calls obesity a chronic, progressive and relapsing disease in which excess body fat impairs health.1
How we researched this
On 12 Oct 2026 we read Obesity Canada’s assessment chapter (2020) and medicines chapter (2025 update), the Canadian labels (product monographs) for Wegovy, Zepbound, Saxenda, Ozempic and Mounjaro, two Canada’s Drug Agency funding recommendations, BC’s Wegovy decision, and two Canadian studies on ethnicity and BMI.
We left out the guideline’s waist table by ethnic group, because the published PDF’s columns didn’t extract cleanly. Inch and pound figures are our conversions.
Before you move on
- BMI is a first screen; the guideline wants waist size and health checked too.
- Asian cut-offs start overweight at a BMI of 23 and use smaller waist sizes.
- Medicines are discussed at a BMI of 30, or 27 with weight-related problems.
- Public plans use narrower rules than the guideline.
More from the Canada blog
The monthly Canada update
An independent guide to GLP‑1 medicines. We don't sell medicines, take drug-company money or earn clinic commissions. Once a month: coverage changes, approvals, safety notices and recalls. How we write
Sources
- Rueda-Clausen CF, Poddar M, Lear SA, Poirier P, Sharma AM. Canadian Adult Obesity Clinical Practice Guidelines: Assessment of People Living with Obesity. Obesity Canada, version 1, 4 August 2020 (Table 1, waist cut-offs, Edmonton Obesity Staging System). obesitycanada.ca (PDF)
- Pedersen SD, Manjoo P, Dash S, Jain A, Pearce N, Poddar M. Canadian Adult Obesity Clinical Practice Guideline: Pharmacotherapy for Obesity Management in Adults, 2025 update. Obesity Canada, version 3, 11 August 2025 (recommendations 1–13; STEP 1 extension, STEP 4, SURMOUNT-4, SELECT, ESSENCE and SURMOUNT-OSA summaries). obesitycanada.ca (PDF)
- Health Canada. Drug Product Database: product records and status for semaglutide, tirzepatide and liraglutide products (all on the prescription schedule; generic semaglutide products from Dr. Reddy’s and Apotex marketed in May 2026; Sevmia, Aspen and Sandoz products approved but not marketed). Searched 12 October 2026. health-products.canada.ca
- Chiu M, Austin PC, Manuel DG, Shah BR, Tu JV. Deriving ethnic-specific BMI cutoff points for assessing diabetes risk. Diabetes Care 2011;34(8):1741–8. Institute for Clinical Evaluative Sciences, Ontario. DOI · PMC3142051
- Razak F, Anand SS, Shannon H et al. Defining obesity cut points in a multiethnic population. Circulation 2007;115(16):2111–8. McMaster University, Hamilton. DOI · PMID 17420343
- Novo Nordisk Canada. Wegovy (semaglutide injection) product monograph, date of authorization 2 October 2026. Sections 1, 2, 4.4, 4.5, 7, 8, 10, 11, 14 and patient information. pdf.hres.ca
- Eli Lilly Canada. Zepbound (tirzepatide injection) product monograph, date of authorization 11 June 2026. Sections 1, 4.4, 4.5, 8, 11, 14. pdf.hres.ca
- Novo Nordisk Canada. Saxenda (liraglutide injection) product monograph, date of authorization 10 September 2025. Sections 1 and 11. pdf.hres.ca
- Novo Nordisk Canada. Ozempic (semaglutide injection) product monograph (the Canadian label), date of authorization 13 July 2026. Sections 1, 4.4, 4.5, 11 and patient information. pdf.hres.ca
- Eli Lilly Canada. Mounjaro (tirzepatide injection) product monograph, date of authorization 23 June 2026. Sections 1 and 11. pdf.hres.ca
- Canada’s Drug Agency (CDA-AMC). Semaglutide (Wegovy) reimbursement recommendation SR0841, July 2025 (“Reimburse with conditions” for adults with BMI 27 or more and established cardiovascular disease; renewal needs at least a 5% reduction; about $5,066 a year). canjhealthtechnol.ca
- BC PharmaCare. Drug coverage decision: semaglutide (Wegovy), “Non-benefit”, 18 December 2025 (pCPA talks ended without agreement on 1 December 2025). gov.bc.ca (PDF)
- Canada’s Drug Agency (CDA-AMC). Tirzepatide (Zepbound) reimbursement recommendation SR0920 (reimburse with conditions for adults with BMI 27 or more and prediabetes; renewal needs at least a 5% reduction in body weight). Expert committee meeting 24 June 2026. canjhealthtechnol.ca
Last checked 12 Oct 2026 · Next review due 12 Oct 2027 · Report an error
How this post was made. Written by the GLP Guidebook team from the sources above. It's general information, not medical, legal or tax advice. Talk to a qualified doctor, nurse practitioner or pharmacist before starting, stopping or changing any medicine. How we write