Diet, exercise can’t cure obesity, doctors say

“Exercise and diet” — that’s the advice doctors have given patients living with obesity for far too long, says Dr. Sean Wharton, an internist in Burlington, Ontario, who treats people living with obesity.

Wharton is one of the authors of new clinical guidelines, two years in the making, for treating obesity in Canada. It is the first major update to obesity treatment guidelines since 2007.

The Canadian Adult Obesity Clinical Practice Guidelines ( CPGS) were developed by Obesity Canada and the Canadian Association of Bariatric Physicians and Surgeons, and authored by more than 60 Canadian health professionals, researchers and individuals living with obesity. The recommendations were published in the Canadian Medical Association Journal (CMAJ).

The authors assessed over 500,000 published peer- reviewed articles on obesity.

In essence, the guidelines recommend that the condition be treated as a chronic illness, not something cured by simple diet and exercise. This should also help end the stigma around obesity.

“Science tells us the drivers of weight gain are complicated and unique to the individual, and also that the human body is hard- wired against weight loss. Historically, we have told people whose weight affects their health merely to eat less and move more, which on its own is ineffective and even dangerously simplistic advice,” said Dr. Arya M. Sharma, scientific director of Obesity Canada.

“The CPGS represent a turning point in the way Canada needs to approach the treatment of obesity, and that is to acknowledge obesity as a complex chronic disease requiring lifelong support, as we do for diabetes, heart disease and others — this is the best evidence to date on how to do that,” said Sharma.

“We’re definitely hoping physicians and people work on their own biases,” said Wharton.

“Our fixation on diet has been failing us for 50 years,” Wharton added. “Going on a diet guarantees you’re going to lose a little bit of weight but you’ll gain a significant amount back.”

Instead, Wharton said obesity needs to be treated as a neurobiological issue, driven by hormones that influence people’s eating habits and behaviours. To that end, patients need approaches to managing how those hormones react in their bodies.

This can be achieved through bariatric surgery, which reduces the size of the stomach, but also affects hormones and gut bacteria that affect hunger. Medications such as glucagon- like peptide 1 ( GLP- 1) agonists can also increase the levels of hormones that make people feel full after eating, while antidepressant/anti-addictive medications can also manage cravings and hunger pangs.

Wharton would also like to see the language around obesity change. Instead of diets, “medical nutrition therapy” can help bring about changes to eating patterns. This means eating to solve a condition without obsessing about calories. He says if a person makes sensible nutritional choices, the “lower calories will come.”

A new approach to obesity is especially important during the pandemic, as the illness is seen as a major risk factor for diabetes and COVID- 19. Research has shown that the adipose tissue of people who live with obesity can lead to inflammation that complicates these conditions and can lead to more severe symptoms.