Obesity in adults: a clinical practice guideline

The CMAJ and its peer reviewers concluded an article written by over 50 authors many sponsored by the pharmaceutical industry with over 80 recommendations would be of practical use to primary health care providers .
Having a BMI over 25 or over is labelled as having the “disease” of obesity . Yet a 2013 study by Health Canada (1) found at age 20 the life expectancy for females[males] with BMI 18.5 to 24.9 (”normal” )was 62.9[57.2] years , who had a BMI 25 to 30 “overweight” was a further 66.5[ 61.0] years and for a BMI 30 to 35, otherwise known as Class 1 obesity, 64.6 [59.1] years . Both “overweight” males and females had a significantly longer life expectancy than those with normal weight . Those with Class 1 obesity still had a longer life expectancy than those with “normal” weight .
A 2018 study (2) of populations in England, Finland, France and Finland between ages 50 and 75 found negligible if any differences in life expectancy between individuals with normal weight ( BMI 18.5- 24.9) overweight ( BMI 25-29.9 ) and class 1 obesity ( BMI 30 to 34.9)
One of the CMAJ recommendations states pharmacotherapy should be considered for individuals with a BMI over over 30 . For the reasons above this would suggest the guideline recommendations for pharmacotherapy are based more on cosmetic considerations rather than health indications.
Stigmatizing those who are “overweight” or have class 1 obesity by calling their condition a disease is not based on medical evidence . Perhaps it is no different than the American Psychiatrtic Association previously calling homosexuality a disease .

Wharton et al. provide a comprehensive resource for effective and ethical obesity management, across many populations and patient circumstances[1]. The specific focus on adult women living with obesity is welcomed, especially as pregnancy, preconception and postpartum are some of the most critical life-course timepoints for the prevention of non-communicable diseases across multiple generations[2]. The authors outline that where possible, adults living with obesity, which includes women of reproductive age, should have access to a registered dietitian for individualized medical nutrition therapy[1]. This is an excellent recommendation, and we also consider it important to advocate that all healthcare providers who see women with obesity, have an opportunity to promote healthy weight and nutrition[3,4]. Due to the growing prevalence of obesity and the associated demand on dietetic services, other healthcare professionals must capitalize on their contact with women and promote healthy behaviour change. It is important that nutrition is seen as a collective global responsibility and is embedded into multi-disciplinary health services, systems and policies[3,4]. The authors recommend that primary care physicians encourage and support pregnant women with obesity to consume a healthy dietary pattern[1]. Advice on how physicians can implement this into their practice, however, is lacking in this review. During pregnancy, women with obesity should be advised to follow a diet that not only manages gestational weight gain but also meets their complex and dynamic nutritional needs for fetal growth and development[4]. The use of checklists in clinical practice has been encouraged by medical organisations[5]. The FIGO Nutrition Checklist is a purposively designed and brief nutritional questionnaire for women before or during pregnancy. It includes questions on personal dietary requirements or practices (e.g. vegan diet), body mass index, diet quality and micronutrients. It can therefore support clinicians who lack dietetic training to implement some of the recommendations outlined by the authors including the provision of dietary advice that is personalized, nutritionally adequate and culturally acceptable. To date, the FIGO Nutrition Checklist has been used in three separate countries in Europe and Asia and adapted to local requirements[2].

We would welcome if Canada would consider use of the FIGO nutrition checklist in supporting healthcare professionals address nutrition and weight at each contact.

I applaud the herculean effort of Wharton et al. to produce timely and comprehensive guidelines on the management of obesity [1], and offer the following comments:

First, despite the wide array of topics covered I am surprised and disappointed that guidelines related to the prevention of obesity are conspicuously absent. With billions of dollars spent annually in Canada towards dietary, pharmacologic, surgical and psychological strategies to treat obesity and its many complications, it is unfortunate that so little attention and resources are dedicated to preventing obesity in children, adolescents and young adults. Perhaps a companion guideline focusing on primary prevention is in the works.

Second, the guideline recommendation format, though well-intentioned, seems unwieldy and, at times, confusing [2]. For example, under pharmacotherapy in obesity management, there are three recommendations, all categorized as having the same level of evidence (Level 2a, Grade B), yet these separate recommendations state that pharmacotherapy “can be used”, “may be used”, and is “recommended”. For clinicians looking for guidance on ‘what to do’, these statements appear ambiguous and inconsistent with the evidence. Rather than adopting a guideline recommendation scheme that is rather outdated [2], there are newer and simpler schemes that provide a more practical approach to treatment recommendations: ‘do it’, or ‘OK to do it or not do it’ [3].

As a third (minor) point, the authors refer to the “first evidence-based Canadian practice guideline on the prevention and treatment of obesity”, published in 2007 [4]. In fact, the Canadian Task Force for Preventive Health Care published such evidence-based guidelines in 1999 [5]; the Task Force has been for decades a highly-respected but under-funded vehicle of practice standards for clinicians in Canada and abroad.

Wharton et al. provide an excellent overview of the complexity of obesity and multiple biological, behavioural, and environmental contributors. While the resulting clinical practice guideline (CPG) provides a launching pad to abandon the flawed notion of obesity as a self-inflicted condition and redefine the clinical approach to obesity treatment and management in Canada, the critical role of retail food environments and affordability of healthy food was regrettably overlooked. While it is appreciated that CPG provide guidance for individual-level strategies, individual efforts without parallel efforts at a community or population-level may limit overall success in improving obesity-related outcomes among patients. Increasing evidence supports a role of retail food environments in body mass index (BMI) (1); however, inconsistent findings are likely due to variability in food environment measurements as well as lack of consideration of inter-individual differences in food cue reactivity. Indeed, recent research supports an argument for inter-individual differences in responsivity to food cues in the retail food environment, including advertising exposures such as in-store food displays (2). While additional research in this area is anticipated, the role of socio-economic status in obesity is more conclusive. Low socio-economic status is consistently associated with obesity, to an extent that an investigation of gene-obesogenic environment interactions in the UK Biobank concluded that low socio-economic position accentuated genetic susceptibility to obesity and best captured the relevant environmental factors (3). Indeed, affordability of healthy food is a recognized barrier to healthy eating and may be a particularly relevant target for obesity intervention. Given this relationship, additional efforts like Geisinger’s Fresh Food Farmacy, which is providing healthy food to people living with diabetes and facing food insecurity, are needed to demonstrate the possible benefit of community intervention at a potential root cause: food affordability. Participants in the Farmacy initiative are prescribed fresh food each week and fill the prescription (pick-up food) at the Farmacy clinic, alleviating financial barriers and retail exposures that pose challenges to healthy eating. Preliminary results from the Geisinger initiative have demonstrated a staggering 2-point reduction in HbA1c levels among participants, along with reductions in low-density lipoproteins, triglycerides, blood pressure, and BMI (4). Wharton et al. have illuminated the urgent need for access to appropriate and holistic obesity care in Canada and provide an excellent CPG to immediately improve the clinical approach. However, in order to more precisely address root causes and fully disrupt conventional approaches to obesity treatment and management, strategies for improving community and population-level factors need attention, investigation, and action.