Table 1:

Recommendations on management of obesity in adults^*

	Recommendations	Category of evidence and strength of recommendation^†
Reducing weight bias in obesity management, practice and policy
1	Health care providers should assess their own attitudes and beliefs regarding obesity and consider how their attitudes and beliefs may influence care delivery.	Level 1a, grade A
2	Health care providers may recognize that internalized weight bias (bias toward oneself) in people living with obesity can affect behavioural and health outcomes.	Level 2a, grade B
3	Health care providers should avoid using judgmental words (level 1a, grade A), images (level 2b, grade B) and practices (level 2a, grade B) when working with patients living with obesity.	See recommendation
4	We recommend that health care providers avoid making assumptions that an ailment or complaint a patient presents with is related to their body weight.	Level 3, grade C
Epidemiology of adult obesity
5	Health care providers can recognize and treat obesity as a chronic disease, caused by abnormal or excess body fat accumulation (adiposity), which impairs health, with increased risk of premature morbidity and mortality.	Level 2b, grade B
6	The development of evidence-informed strategies at the health system and policy levels can be directed at managing obesity in adults.	Level 2b, grade B
7	Continued longitudinal national and regional surveillance of obesity that includes self-reported and measured data (i.e., height, weight, waist circumference) may be collected on a regular basis.	Level 2b, grade B
Enabling participation in activities of daily living for people living with obesity
8	We recommend that health care providers ask people living with obesity if they have concerns about managing self-care activities, such as bathing, getting dressed, bowel and bladder management, skin and wound care, and foot care.	Level 3, grade C
9	We recommend that health care providers assess fall risk in people living with obesity, as this could interfere with their ability and interest in participating in physical activity.	Level 3, grade C
Assessment of people living with obesity
10	We suggest that health care providers involved in screening, assessing and managing people living with obesity use the 5As framework (see Appendix 2^‡) to initiate the discussion by asking for their permission and assessing their readiness to begin treatment.	Level 4, grade D (consensus)
11	Health care providers can measure height, weight and calculate the BMI in all adults (level 2a, grade B), and measure waist circumference in individuals with a BMI 25–35 kg/m² (level 2b, grade B).	See recommendation
12	We suggest that a comprehensive history to identify root causes of weight gain as well as complications of obesity and potential barriers to treatment be included in the assessment.	Level 4, grade D
13	We recommend measuring blood pressure in both arms, fasting glucose or glycated hemoglobin and lipid profile to determine cardiometabolic risk and, where appropriate, ALT to screen for nonalcoholic fatty liver disease in people living with obesity.	Level 3, grade D
14	We suggest that health care providers consider using the Edmonton Obesity Staging System (see Appendix 1)^§ to determine the severity of obesity and guide clinical decision-making.	Level 4, grade D
The role of mental health in obesity management
15	We recommend regular monitoring of weight, glucose and lipid profile in people with a mental health diagnosis and who are taking medications associated with weight gain.	Level 3, grade C
16	Health care providers may consider both efficacy and effects on body weight when choosing psychiatric medications.	Level 2a, grade B
17	Metformin and psychological treatment such as cognitive behavioural therapy should be considered for prevention of weight gain in people with severe mental illness who are treated with antipsychotic medications associated with weight gain.	Level 1a, grade A
18	Health care providers should consider lisdexamfetamine and topiramate as an adjunct to psychological treatment to reduce eating pathology and weight in people with overweight or obesity and binge-eating disorder.	Level 1a, grade A
Medical nutrition therapy in obesity management
19	We suggest that nutrition recommendations for adults of all body sizes be personalized to meet individual values, preferences and treatment goals to support a dietary approach that is safe, effective, nutritionally adequate, culturally acceptable and affordable for long-term adherence.	Level 4, grade D
20	Adults living with obesity should receive individualized medical nutrition therapy provided by a registered dietitian (when available) to improve weight outcomes (body weight, BMI), waist circumference, glycemic control, established lipid, and blood pressure targets.	Level 1a, grade A
21	Adults living with obesity and impaired glucose tolerance (prediabetes) or type 2 diabetes may receive medical nutrition therapy provided by a registered dietitian (when available) to reduce body weight and waist circumference and improve glycemic control and blood pressure.	Level 2a, grade B
22	Adults living with obesity can consider any of multiple medical nutrition therapies to improve health-related outcomes, choosing the dietary patterns and food-based approaches that support their best long-term adherence. (Full recommendation and category and level of evidence available in the chapter titled “Medical nutrition therapy in obesity management.”)	See recommendation
23	Adults living with obesity and impaired glucose tolerance (prediabetes) should consider intensive behavioural interventions that target a 5%–7% weight loss, to improve glycemic control, blood pressure and blood lipid targets (level 1a, grade A) and reduce the incidence of type 2 diabetes (level 1a, grade A), microvascular complications (retinopathy, nephropathy and neuropathy) (level 1a, grade B), and cardiovascular and all-cause mortality (level 1a, grade B).	See recommendation
24	Adults living with obesity and type 2 diabetes should consider intensive lifestyle interventions that target a 7%–15% weight loss, to increase the remission of type 2 diabetes and reduce the incidence of nephropathy, obstructive sleep apnea and depression.	Level 1a, grade A
25	We recommend a nondieting approach to improve quality of life, psychological outcomes (general well-being, body image perceptions), cardiovascular outcomes, body weight, physical activity, cognitive restraint and eating behaviours.	Level 3, grade C
Physical activity in obesity management
26	Aerobic physical activity (30–60 minutes of moderate to vigorous intensity most days of the week) can be considered for adults who want to: Achieve small amounts of body weight and fat loss (level 2a, grade B) Achieve reduction in abdominal visceral fat (level 1a, grade A) and ectopic fat, such as liver and heart fat (level 1a, grade A), even in the absence of weight loss Favour weight maintenance after weight loss (level 2a, grade B) Favour the maintenance of fat-free mass during weight loss (level 2a, grade B) Increase cardiorespiratory fitness (level 2a, grade B) and mobility (level 2a, grade B).	See recommendation
27	For adults living with overweight or obesity, resistance training may promote weight maintenance or modest increases in muscle mass or fat-free mass and mobility.	Level 2a, grade B
28	Increasing exercise intensity, including high-intensity interval training, can achieve greater increases in cardiorespiratory fitness and reduce the amount of time required to achieve benefits similar to those from moderate-intensity aerobic activity.	Level 2a, grade B
29	Regular physical activity, with and without weight loss, can improve many cardiometabolic risk factors in adults who have overweight or obesity, including hyperglycemia and insulin sensitivity (level 2b, grade B), high blood pressure (level 1a, grade B) and dyslipidemia (level 2a, grade B).	See recommendation
30	Regular physical activity can improve health-related quality of life, mood disorders (i.e., depression, anxiety) and body image in adults living with overweight or obesity.	Level 2b, grade B
Effective psychological and behavioural interventions in obesity management
31	Multicomponent psychological interventions (combining behaviour modification [goal-setting, self-monitoring, problem-solving], cognitive therapy [reframing] and values-based strategies to alter diet and activity) should be incorporated into care plans for weight loss, and improved health status and quality of life (level 1a, grade A) in a manner that promotes adherence, confidence and intrinsic motivation (level 1b, grade A).	See recommendation
32	Health care providers should provide longitudinal care with consistent messaging to people living with obesity in order to support the development of confidence in overcoming barriers (self-efficacy) and intrinsic motivation (personal, meaningful reasons to change), to encourage the patient to set and sequence health goals that are realistic and achievable, to self-monitor behaviour and to analyze setbacks using problem-solving and adaptive thinking (cognitive reframing), including clarifying and reflecting on values-based behaviours.	Level 1a, grade A
33	Health care providers should ask people living with obesity for permission to educate them that success in obesity management is related to improved health, function and quality of life resulting from achievable behavioural goals and not on the amount of weight loss.	Level 1a, grade A
34	Health care providers should provide follow-up sessions consistent with repetition and relevance to support the development of self-efficacy and intrinsic motivation. (Full recommendation is available in the chapter titled “Effective psychological and behavioural interventions in obesity management.”)	Level 1a, grade A
Pharmacotherapy in obesity management
35	Pharmacotherapy for weight loss can be used for persons with BMI ≥ 30 kg/m² or BMI ≥ 27 kg/m² with adiposity-related complications, in conjunction with medical nutrition therapy, physical activity and psychological interventions (liraglutide 3.0 mg, naltrexone-bupropion combination, orlistat).	Level 2a, grade B
36	Pharmacotherapy may be used to maintain weight loss that has been achieved by health behaviour changes, and to prevent weight regain (liraglutide 3.0 mg or orlistat).	Level 2a, grade B
37	For people living with type 2 diabetes and a BMI ≥ 27 kg/m², pharmacotherapy can be used in conjunction with health behaviour changes for weight loss and improvement in glycemic control: liraglutide 3.0 mg (level 1a, grade A), naltrexone-bupropion combination (level 2a, grade B), orlistat (level 2a, grade B).	See recommendation
38	We recommend pharmacotherapy in conjunction with health behaviour changes for people living with prediabetes and overweight or obesity (BMI ≥ 27 kg/m²) to delay or prevent type 2 diabetes (liraglutide 3.0 mg; orlistat).	Level 2a, grade B
39	We do not suggest the use of prescription or over-the-counter medications other than those approved for weight management.	Level 4, grade D (consensus)
40	For people living with overweight or obesity who require pharmacotherapy for other health conditions, we suggest choosing drugs that are not associated with weight gain.	Level 4, grade D (consensus)
Bariatric surgery: selection and preoperative workup
41	We suggest that a comprehensive medical and nutritional evaluation be completed and nutrient deficiencies corrected in candidates for bariatric surgery.	Level 4, grade D
42	Preoperative smoking cessation can minimize perioperative and postoperative complications.	Level 2a, grade B
43	We suggest screening for and treatment of obstructive sleep apnea in people seeking bariatric surgery.	Level 4, grade D
Bariatric surgery: surgical options and outcomes
44	Bariatric surgery can be considered for people with BMI ≥ 40 kg/m² or BMI ≥ 35 kg/m² with at least 1 adiposity-related disease (level 4, grade D, consensus) to: Reduce long-term overall mortality (level 2b, grade B) Induce significantly better long-term weight loss compared with medical management alone (level 1a, grade A) Induce control and remission of type 2 diabetes, in combination with best medical management, over best medical management alone (level 2a, grade B) Significantly improve quality of life (level 3, grade C) Induce long-term remission of most adiposity-related diseases, including dyslipidemia (level 3, grade C), hypertension (level 3, grade C), liver steatosis and nonalcoholic steatohepatitis (level 3, grade C).	See recommendation
45	Bariatric surgery should be considered in patients with poorly controlled type 2 diabetes and class I obesity (BMI between 30 and 35 kg/m²) despite optimal medical management.	Level 1a, grade A
46	Bariatric surgery may be considered for weight loss and/or to control adiposity-related diseases in persons with class 1 obesity, in whom optimal medical and behavioural management has been insufficient to produce significant weight loss.	Level 2a, grade B
47	We suggest that the choice of bariatric procedure (sleeve gastrectomy, gastric bypass or duodenal switch) be decided according to the patient’s need, in collaboration with an experienced interprofessional team.	Level 4, grade D (consensus)
48	We suggest that adjustable gastric banding not be offered owing to unacceptable complications and long-term failure.	Level 4, grade D
49	We suggest that single anastomosis gastric bypass not be routinely offered, owing to long-term complications in comparison with Roux-en-Y gastric bypass.	Level 4, grade D
Bariatric surgery: postoperative management
50	Health care providers can encourage persons who have undergone bariatric surgery to participate in and maximize their access to behavioural interventions and allied health services at a bariatric surgical centre.	Level 2a, grade B
51	We suggest that bariatric surgical centres communicate a comprehensive care plan to primary care providers for patients who are discharged, including bariatric procedure, emergency contact numbers, annual blood tests required, long-term vitamin and minerals supplements, medications and behavioural interventions, as well as when to refer back.	Level 4, grade D (consensus)
52	We suggest that after a patient has been discharged from the bariatric surgical centre, primary care providers conduct annual review of the following: weight, nutritional intake, activity, adherence to multivitamin and mineral supplements, assessment of comorbidities and laboratory tests to assess and treat for nutritional deficiencies as required.	Level 4, grade D (consensus)
53	We suggest that primary care providers consider referral back to the bariatric surgical centre or to a local specialist for technical or gastrointestinal symptoms, nutritional issues, pregnancy, psychological support, weight regain or other medical issues related to bariatric surgery, as described in the chapter titled “Bariatric surgery: postoperative management.	Level 4, grade D (consensus)
54	We suggest that bariatric surgical centres provide follow-up and appropriate laboratory tests at regular intervals postsurgery with access to appropriate health care professionals (dietitian, nurse, social worker, bariatric physician, surgeon, psychologist or psychiatrist) until discharge is deemed appropriate for the patient.	Level 4, grade D (consensus)
Primary care and primary health care in obesity management
55	We recommend that primary care clinicians identify people with overweight and obesity, and initiate patient-centred, health-focused conversations with them.	Level 3, grade C
56	We recommend that health care providers ensure they ask people for their permission before discussing weight or taking anthropometric measurements.	Level 3, grade C
57	Primary care interventions should be used to increase health literacy in individuals’ knowledge and skill about weight management as an effective intervention to manage weight.	Level 1a, grade A
58	Primary care clinicians should refer persons with overweight or obesity to primary care multicomponent programs with personalized obesity management strategies as an effective way to support obesity management.	Level 1b, grade B
59	Primary care clinicians can use collaborative deliberation with motivational interviewing to tailor action plans to individuals’ life context in a way that is manageable and sustainable to support improved physical and emotional health, and weight management.	Level 2b, grade C
60	Interventions that target a specific ethnic group should consider the diversity of psychological and social practices with regard to excess weight, food and physical activity, as well as socioeconomic circumstances, as they may differ across and within different ethnic groups.	Level 1b, grade B
61	Longitudinal primary care interventions should focus on incremental, personalized, small behaviour changes (the “small change approach”) to be effective in supporting people to manage their weight.	Level 1b, grade B
62	Primary care multicomponent programs should consider personalized obesity management strategies as an effective way to support people living with obesity.	Level 1b, grade B
63	Primary care interventions that are behaviour based (nutrition, exercise, lifestyle), alone or in combination with pharmacotherapy, should be used to manage overweight and obesity.	Level 1a, grade A
64	Group-based diet and physical activity sessions informed by the Diabetes Prevention Program and the Look AHEAD (Action for Health in Diabetes) programs should be used as an effective management option for adults with overweight and obesity.	Level 1b, grade A
65	Interventions that use technology to increase reach to larger numbers of people asynchronously should be a potentially viable lower cost intervention in a community-based setting.	Level 1b, grade B
66	Educators of undergraduate, graduate and continuing education programs for primary health care professionals should provide courses and clinical experiences to address the gaps in skills, knowledge of the evidence, and attitudes necessary to confidently and effectively support people living with obesity.	Level 1a, grade A
Commercial products and programs in obesity management
67	For adults living with overweight or obesity, the following commercial programs should achieve mild to moderate weight loss in the short or medium term, compared with usual care or education: WW (formerly Weight Watchers) (level 1a, grade A) Optifast (level 1b, grade B) Jenny Craig (level 1b, grade B) Nutrisystem (level 1b, grade B)	See recommendation
68	Optifast, Jenny Craig, WW (formerly Weight Watchers) and Nutrisystem should achieve a mild reduction of glycated hemoglobin values over a short-term period compared with usual counselling in adults with obesity and type 2 diabetes.	Level 1b, grade B
69	We do not recommend the use of over-the-counter commercial weight-loss products for obesity management, owing to lack of evidence.	Level 4, grade D
70	We do not suggest that commercial weight-loss programs be used for improvement in blood pressure and lipid control in adults living with obesity.	Level 4, grade D
Emerging technologies and virtual medicine in obesity management
71	Implementation of management strategies can be delivered through Web-based platforms (e.g., online education on medical nutrition therapy and physical activity) or mobile devices (e.g., daily weight reporting through a smartphone application) in the management of obesity.	Level 2a, grade B
72	We suggest that health care providers incorporate individualized feedback and follow-up (e.g., personalized coaching or feedback via phone or email) into technology-based management strategies to improve weight-loss outcomes.	Level 4, grade D
73	The use of wearable activity tracking technology should be part of a comprehensive strategy for weight management.	Level 1a, grade A
Weight management over the reproductive years for adult women living with obesity
74	We recommend that primary care providers discuss weight-management targets specific to the reproductive years with adult women with obesity: preconception weight loss (level 3, grade C); gestational weight gain of 5 kg to 9 kg over the entire pregnancy (level 4, grade D); postpartum weight loss of — at minimum — gestational weight gain (level 3, grade C) to reduce the risk of adverse outcomes in the current or in a future pregnancy.	See recommendation
75	Primary care providers should offer behaviour change interventions including both nutrition and physical activity to adult women with obesity who are considering a pregnancy (level 3, grade C), who are pregnant (level 2a, grade B) and who are postpartum (level 1a, grade A) in order to achieve weight targets.	See recommendation
76	We recommend that primary care providers encourage and support pregnant women with obesity to consume foods consistent with a healthy dietary pattern in order to meet their target gestational weight gain.	Level 3, grade C
77	We recommend that primary care providers encourage and support pregnant women with obesity who do not have contraindications to exercise during pregnancy to engage in at least 150 minutes per week of moderate intensity physical activity, to assist in the management of gestational weight gain.	Level 3, grade C
78	Health care providers should not prescribe metformin for gestational weight gain in pregnant women with obesity (level 1b, grade A). We suggest that weight-management medications not be used during pregnancy or breastfeeding (level 4, grade D).	See recommendation
79	We recommend that women with obesity be offered additional breastfeeding support because of decreased rates of initiation and continuation.	Level 3, grade C
Obesity management and Indigenous Peoples
80	We suggest that health care providers for Indigenous people living with obesity: Engage with the patient’s social realities. Validate the patient’s experiences of stress and systemic disadvantage influencing poor health and obesity, exploring elements of their environment where reduced stress could shift behaviours. Advocate for access to obesity-management resources within publicly funded health care systems, recognizing that resources beyond may be unaffordable and unattainable for many. Help patients recognize that good health is attainable, and they are entitled to it. Negotiate small, attainable steps relevant to the patient’s context. Address resistance, seeming apathy and paralysis in patients and providers. Self-reflect on anti-Indigenous sentiment common within health care systems, exploring patient motivations and mental health (e.g., trauma, grief) as alternative understandings of causes and solutions to their health problems. Explore one’s own potential for bias influenced by systemic racism. Expect patient mistrust in health systems; reposition themselves as a helper to the patient instead of as an expert, which may stir resistance and be a barrier to patients’ wellness. When resistance, seeming apathy and paralysis are encountered, explore patient mental and emotional health needs, which have unique drivers and presentations in many Indigenous contexts. Build complex knowledge by healing relationships. Build patient knowledge and capacity for obesity self-management through longitudinal explorations of co-occurring health, social, environmental and cultural factors. Strive to build relationships that incorporate healing from multigenerational trauma that, owing to residential schools and child welfare system involvement, may more frequently include sexual abuse. Build their own knowledge regarding the health legacy of colonization — including ongoing experiences of anti-Indigenous discrimination within systems and wider society — to facilitate relationships built on mutual understanding. Ensure knowledge provided is congruent with the patient’s perspectives and educational level, and is learner centred, including potential for patient anticipation of racism or unequal treatment. Connect to behaviour, the body and Indigenous ways of knowing, doing and being. Elicit and incorporate the patient’s individual and community-based concepts of health and healthy behaviours in relation to body size, activity and food preferences (e.g., preference for or scarce access to land-based foods and activities). Deeply engage in learning of common values and principles regarding communication and knowledge-sharing in Indigenous contexts (e.g., relationalism, noninterference).	Level 4, grade D (consensus)

Note: ALT = alanine aminotransferase, BMI = body mass index.
↵* A complete description of the recommendations and supporting evidence is available at http://obesitycanada.ca/guidelines/. Table 3 provides definitions for the actionable verbs used in these recommendations.
↵† For the classification scheme for category of evidence and strength of evidence, see Box 3.
↵‡ Appendix 2 is available at www.cmaj.ca/lookup/suppl/doi:10.1503/cmaj.191707/-/DC2.
↵§ See Appendix 1.