Emerging research captured in revised chapters summarizing evidence for medical nutrition therapy and pharmacotherapy

EDMONTON, October 21, 2022 – Canadian healthcare professionals who support patients living with obesity now have up-to-date information on the latest evidence for two important obesity treatment paradigms: medical nutrition therapy (MNT) and pharmacotherapy. 

Obesity Canada and the Canadian Association of Bariatric Physicians and Surgeons launched the Canadian Adult Obesity Clinical Practice Guidelines (CPGs) in 2020 after an exhaustive two-year assessment of more than 500,000 peer reviewed papers. A summary of 80 clinical recommendations was published in the Canadian Medical Association Journal in August of 2020, becoming the journal’s top-read paper in the first year of the COVID-19 pandemic. Nineteen supplementary chapters that go into great detail on a wide range of obesity prevention and treatment issues were simultaneously published at www.obesitycanada.ca/guidelines

The core pillars of obesity management in the CPGs include psychological/behavioural interventions, medications and bariatric surgery, for which medical nutrition therapy and physical activity act as adjunctive therapies. The CPGs were created as a living knowledge repository, to be updated when significant new research is published. 

“The literature search and evidence synthesis for the guidelines was a labour-intensive and time-consuming task, and so our original date range for assessing peer-reviewed papers was January 2006 to June 2018,” says Dr. Mary Forhan, Scientific Director for Obesity Canada and Associate Professor and Chair of the Department of Occupational Science and Occupational Therapy at the University of Toronto. “There is heightened interest in obesity research today, and we felt that there were enough new publications in pharmacotherapy – coinciding with the approval of a fourth obesity medication in Canada – and medical nutrition therapy to warrant updates to these chapters.”

Dr. Forhan added that MNT chapter authors updated a literature review between November 2018 and March 2021 to determine if any significant evidence has emerged that would support clinical practice. Two areas were identified as providing updated evidence currently in the MNT chapter recommendations: i) use of partial meal replacements; and ii) intermittent fasting. Neither area provided enough evidence to change the current recommendations, but an updated list of references is available for readers of the chapter. 

The medication chapter updated recommendations to include the fourth medication now approved for obesity management in Canada, semaglutide 2.4mg.  There are new recommendations on the use of pharmacotherapy in combination with health-behaviour changes to i) treat people with obstructive sleep apnea and BMI ≥ 30 kg/m2 for weight loss and associated improvement in apnea-hypopnea index and  ii) treat people living with non-alcoholic steatohepatitis (NASH) and overweight or obesity for weight loss and improvement of NASH parameters. A third new recommendation suggests that 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. New sections include the effect of obesity medications on cravings and quality of life, two aspects of obesity care that are important for many patients. The chapter also discusses the role of emerging medications such as tirzepatide and setmelanotide. 

The methodologies for updating each chapter are on the CPG site. 

“Updates to the CPGs are important to ensure Obesity Canada is providing the most up-to-date evidence for healthcare providers and patients to make shared decisions,” Dr. Forhan added. “We will continue to revisit each recommendation when new research suggests a change to our recommendations is warranted.” 

More information or to arrange interviews: Nicole Pearce, Obesity Canada, pearce@obesitynetwork.ca

About Obesity Canada

Obesity Canada-Obésité Canada is Canada’s authoritative voice on evidence-based approaches for obesity prevention, treatment, and policy. Our mission is to improve the lives of Canadians affected by obesity through the advancement of anti-discrimination, prevention, and treatment efforts. www.obesitycanada.ca