Obesity is not defined by one’s weight or size, but by whether a person’s body fat impairs their health, according to new clinical guidelines for managing the condition.
The guidelines, developed by the Obesity Canada and the Canadian Association of Bariatric Physicians and Surgeons, describe obesity as a complex chronic disease, one that cannot simply be resolved by eating less and exercising more. And while obesity is traditionally defined as having a body mass index, or BMI, of 30 or more, the authors offer a new definition.
“It’s not about the amount of body fat, it’s not about where the body fat is. It’s not about the type of body fat,” said Arya Sharma, scientific director of Obesity Canada and one of the more than 60 authors. “It’s just a very, very simple question. And that is: Does this person’s body fat or excess body fat affect their health? If it does, we’ve got obesity. If it doesn’t, we just have a large person with a lot of body fat.”
The guidelines, summarized in a paper published in the Canadian Medical Association Journal on Tuesday, reflect a paradigm shift in approaching obesity, with a focus on improving patients’ health rather than merely on weight loss.
Traditionally, doctors and other health experts have regarded obesity as a risk factor for other health conditions, such as diabetes, cardiovascular disease and sleep apnea. While this still holds true, in recent years, a growing number experts have also come to recognize that obesity itself is a chronic disease, one that is caused by myriad genetic, metabolic, behavioural and environmental factors, Dr. Sharma explained.
“It’s not as simple as to say that people are getting fat because they’re eating junk food. No, it’s a lot more complex than that,” he said, explaining people’s bodies resist losing weight and regain it as soon as they quit adhering to any kind of diet or weight-loss strategy. “That’s what makes this a chronic condition. … You’re always going to be fighting this pretty much for the rest of your life.”
All of this has implications for how doctors should assess, treat and manage obesity, the authors said, drawing on more than 500,000 published peer-reviewed scientific articles.
Doctors should still measure patients’ weight, height, waist circumference and BMI as part of routine physical exams, they said, but noted physicians should dig deeper to identify the root causes of weight gain. They recommended taking additional measurements, such as blood pressure, fasting glucose and a lipid panel, as well as other exams and tests, depending on the doctors’ clinical judgment.
Adults with obesity should receive individualized care that makes sense for them over the long term, said Dr. Sharma, whose organization connects members of the public affected by obesity, researchers, health professionals and others with an interest in the health concern.
In addition to managing nutrition and physical activity, this can involve a combination of psychological and behavioural interventions, such as cognitive therapy, as well as medications and bariatric surgery.
The guidelines also emphasize the need to address bias and discrimination against individuals based on their weight. Misconceptions that people with obesity lack willpower or motivation persist among health care professionals, and even among patients themselves, which can be a barrier to effective treatment, Dr. Sharma said.
“There’s this idea that if you’re using medication or using surgery, then you’re somehow cheating,” he said.
Yet he noted no one would think someone is cheating or “taking the easy way out” if they took insulin for diabetes or received a kidney transplant if they had chronic kidney disease.
Ian Patton, one of the authors and the director of advocacy and public engagement at Obesity Canada, has encountered his fair share of weight discrimination.
Despite excelling in sports, he was bullied for his size while growing up. Obesity did not become a health issue for him until he approached his 30s and struggled with hypertension and severe sleep apnea. He lacked energy, had constant pain and was always out of breath.
Dr. Patton, who is a registered kinesiologist and exercise physiologist, tried countless diets and supplements and turned to various dietitians and doctors, but found no real help until he was referred to a bariatric program.
Part of the problem, he explained, is that health professionals often instantly judge people with obesity as “stupid and lazy and not worthy of equal care.” In addition, most doctors in Canada receive very little training in obesity management, and those who specialize in obesity medicine are few, he said.
As a result, “the advice that we get, in general, tends to be the same crap that you hear from everyone else” – that is, to eat less and move more, he said.
Mehran Anvari, a professor of surgery at McMaster University in Hamilton and chair of the Ontario Bariatric Network, who was not one of the authors, said guidelines such as this are needed, since obesity remains poorly understood and poorly treated in Canada. Access to bariatric programs varies across the country, he said, noting he hoped to see more medical, surgical and dietary services for obesity in areas where patients are inadequately served.
Sasha High, an internal medicine specialist and medical director of the High Metabolic Clinic in Mississauga, who also was not involved in the guidelines, added that provincial health plans do not cover medications for treating obesity, which can be cost prohibitive.
Many insurance companies also do not cover them because they do not consider a obesity to be a chronic disease, she said. Yet medications can play an important role in treating the underlying biology, including brain and hormonal changes, behind disrupted weight regulation.
Dr. High also said it is important to focus on preventing obesity in the first place. “Once we’ve gained the weight, it’s actually harder to lose it,” she said.
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