Obesity in Adults—Clinician FAQ

The CTFPHC released the “Recommendations for prevention of weight gain and use of behavioural and pharmacologic interventions to manage overweight and obesity in adults in primary care” in 2015.

The task force recognizes that this guideline is currently out-of-date and has made a decision to “sunset” (archive) these recommendations. This was based on a review of the current evidence following the https://canadiantaskforce.ca/methods/updating-reaffirmation-and-sunsetting-clinical-practice-guidelines-methods-from-the-canadian-task-force-on-preventive-health-care/ methodology.

The decision to sunset the guideline was due to the following changes:

  • The evolving concept of obesity as a health issue (e.g., risk factor vs chronic disease or disorder) and resultant impact on selecting appropriate health outcomes
  • Substantial development in obesity treatment including pharmaceutical and surgical interventions that are beyond the scope of the Task Force mandate on preventive health care
  • Availability of a comprehensive Canadian guideline on obesity in adults

The task force acknowledges the importance of this topic to the health and wellbeing of Canadians. During future topic selection, we may re-evaluate aspects of this topic that are better suited to the Task Force mandate.


  1. What are the CTFPHC’s recommendations for preventing weight gain?
    • We do not recommend offering programs aimed at preventing weight gain for healthy adults with a Body Mass Index (BMI) between 18.5 and 24.9, as evidence for such programs is limited.
  2. How do I implement this recommendation?
    • This is a weak recommendation, so clinicians should use their judgment in determining whether a particular patient might benefit from being offered or referred to a program.
    • For example, if an individual expresses concerns about weight gain or is motivated to make lifestyle changes, the clinician should consider referral to a program consistent with the person’s values and preferences.

    Structured behavioural interventions: programs focused on behaviour modification that involve several sessions over weeks to months.


  1. What are the CTFPHC’s recommendations for managing weight gain?
    • We strongly recommend that patients who are obese (30 ≤ BMI < 40) and who are at high risk of type 2 diabetes be referred to a formal diabetes prevention program.
    • Such programs can reduce the risk of diabetes for some people who make lifestyle changes (modified diet and increased physical activity).
    • We also recommend offering overweight and obese patients referral to programs aimed at weight loss. This is a weak recommendation.
    • We don’t recommend offering pharmacological therapies, such as orlistat or metformin, to overweight or obese patients for the purpose of weight loss. This is a weak recommendation.
  2. How do I implement the weak recommendations?
    • A weak recommendation implies that many overweight and obese individuals may benefit from formal diabetes prevention programs, but others may not (e.g., individuals who do not value the short-term benefits of these programs).
    • Similarly, pharmacological therapy may not be appropriate for most individuals, but it may be suitable for some (e.g., individuals who are less concerned about the harms of medication).
    • Management decisions should be consistent with patients’ values and preferences.
  3. Which features should I look for when selecting a commercial or community program?
    • Commercial programs are largely unregulated, unless they include supplements that fall under Health Canada’s Natural Products Act. The most effective interventions vary substantially, and availability of programs may vary from province to province. Therefore, physicians should seek out local expertise to find reputable programs.
    • According to our review, the most effective programs included the following elements:
      • were over 12 months in duration
      • focused on diet, physical activity, and lifestyle changes and were tailored to meet individual needs
      • included combinations of goal-setting and/or active use of self-monitoring
      • used multiple modes of delivery, such as a combination of group and individual sessions or a combination of individual sessions and technology-based components
  4. What are realistic weight loss goals for overweight or obese patients?
    • On the basis of the evidence review, we found an average weight loss of 3 kg over 12 months in mixed-weight populations.


  1. To whom do these recommendations apply?
    • These recommendations apply to adults ≥ 18 years of age.
    • They do not apply to pregnant women and people with health conditions where weight loss is inappropriate.
    • They do not apply to people with BMI ≥ 40, who will benefit from specialized bariatric programs.


  1. Why does the CTFPHC recommend calculating BMI?
    • We recommend routinely measuring height and weight and then calculating BMI at appropriate primary care visits.
    • Calculation of BMI is feasible, and there is evidence showing that it is the body composition measure most strongly associated with mortality.
    • BMI can be used as a basis for weight management but should be considered in the context of a patient’s overall health to inform clinical decision-making; it should not be used in isolation.
    • For some patients, measurement of waist circumference will also be required as part of risk assessment for diabetes and/or cardiovascular risk.
  2. Are there different BMI cut-points for different racial or ethnic groups?
    • Currently, there is no strong evidence to support using different BMI cut-points for different groups.