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Published on November 8, 2022 | http://doi.org/10.5867/medwave.2022.10.2649
Obesity in adults: Clinical practice guideline adapted for Chile
Obesidad en adultos: guía de práctica clínica adaptada para Chile
Introduction The Chilean Society of Bariatric and Metabolic Surgery, together with other scientific societies, led a process for adapting the Canadian clinical practice guideline for obesity in adults for Chile. The aim of the Canadian guideline, among its main objectives, was to propose changes in obesity management using a chronic disease framework and focusing on improving patient-centered health outcomes, rather than focusing on weight loss alone.
Methods A group of 58 healthcare professionals applied the GRADE-Adolopment method to analyze and adapt the original recommendations and to create de novo recommendations. New recommendations were developed through a systematic review of the evidence using the Epistemonikos database and based on the GRADE-Evidence to Decision (EtD) framework.
Results Seventy-six (76) of the 80 original recommendations were adopted, one recommendation was adapted, and 12 new recommendations were created.
Conclusions The adaptation process reduced the time needed to develop a Chilean clinical practice guideline for the management of obesity in adults. The change in obesity management approaches towards non-stigmatizing and patient-centered strategies focused on improving health outcomes and not solely on weight reduction is universal and it is possible to apply this approach in different countries and contexts.
- Obesity is a chronic, prevalent, multifactorial, progressive, and relapsing disease characterized by an abnormal or excessive accumulation of dysfunctional body fat that impairs health.
- People living with obesity face prejudice and stigma that contribute to increased morbidity and mortality, regardless of weight or body mass index.
- This update reflects substantial advances in the epidemiology, causes, pathophysiology, assessment, prevention, and treatment of obesity and shifts the focus of therapy toward improving patient-centered health outcomes rather than weight loss as the sole goal.
- The Edmonton Obesity Staging System guides clinical decisions based on assessing people living with obesity independent of body mass index or waist circumference and is a better predictor of all-cause mortality. However, no studies validate this system in the Chilean population.
- This guideline is oriented toward health professionals, especially in primary care, and people living with obesity, their families, and decision-makers involved in managing and administering resources for obesity care.
- This guideline also focuses on adult obesity and aims to be an updated document on inter- and multidisciplinary management, free of stigmatization, including treatments that have proven effective and safe according to available evidence.
Obesity is a complex, multifactorial, chronic disease in which excess adipose tissue or accumulation of dysfunctional adipose tissue has negative health consequences, increasing the risk of long-term medical complications by its association with multiple diseases. Also, obesity leads to impaired quality of life and reduced life expectancy . Epidemiological studies define obesity by calculating the body mass index (BMI: weight divided by the square of height in meters), which allows stratifying obesity-related health risks at a population level. Operationally, it is diagnosed in patients with a body mass index equal to or greater than 30 kilograms per square meter and is subclassified into class one (equal to or greater than 30 to 34.9 kilograms per square meter), class two (equal to or greater than 35 to 39.9 kilograms per square meter) and class three (equal to or greater than 40 kilograms per square meter). At a population level, health complications from excess body fat increase as the body mass index increases . At an individual level, complications are caused by a complex interaction between excess adiposity, its location and distribution, and many other factors, such as environmental, genetic, biological, and socioeconomic factors  (Table 1).
During the last three decades, the prevalence of obesity has steadily increased worldwide [1,2]. Currently, Chile leads the world rankings of obesity, presenting one of the highest prevalences . According to data from the latest National Health Survey (2016 and 2017), the population over 15 years of age with obesity reached 34.4%, while overweight reached 40%. On the other hand, the prevalence of overweight has increased by 6% since the 1980s , up to 74.2% according to data from the latest National Health Survey .
Following the sustained increase in the prevalence of obesity in our country and its adverse effects on health, in July 2021, Resolution Project No. 1365 was unanimously approved. This resolution requests the President of the Republic to "recognize obesity as a chronic disease whose prevention, diagnosis, treatment, and follow-up should receive financial coverage by the State and Social Security Health Institutions, facilitating the population’s access to adequate healthcare (consultations, examinations, drugs and supplies, surgical procedures, bed days, and controls)" . The unanimous approval of this resolution demonstrates the recognition of obesity as a profound public health problem that must receive effective and timely treatment. The importance of obesity as a public health problem is demonstrated not only by its negative impact on physical and psychological health  but also by the significant increase in healthcare costs [9,10]. Additionally, people with obesity experience widespread weight prejudice and stigma, contributing to increased morbidity and mortality regardless of weight or body mass index .
Obesity is caused by the complex interaction of multiple genetic, metabolic, behavioral, and environmental factors. However, the latter two factors are believed to be the leading cause of the considerable increase in its prevalence [12,13]. During the last decades, a better understanding of its complex etiopathogenesis and biological underpinnings has been achieved . Regarding the genetics of obesity, genome-wide association studies in large epidemiological cohorts have identified more than 140 regions of the genome that influence body mass index. In turn, those possessing significant association with excess weight are the intronic regions of the FTO gene . Studies with monozygotic and dizygotic twins have shown a relatively high degree of heritability and support evidence of heritability of body weight and eating behavior [15,16].
The brain plays a crucial role in energy homeostasis by regulating food intake and caloric expenditure . Decreased food intake and increased physical activity lead to a negative energy balance and trigger adaptive metabolic and neurohormonal mechanisms [18,19]. Targeted therapies to treat these alterations of neurohormonal mechanisms may become effective tools for the long-term treatment of obesity  (Table 2).
Approach to obesity
New approaches have been proposed to diagnose and evaluate people living with obesity in clinical practice [3,12,13,21]. Although body mass index is widely used to assess and classify obesity, it is not an accurate screening tool for adiposity-related complications . Waist circumference has been independently associated with increased cardiovascular risk but is not a good predictor of visceral adipose tissue individually . Integrating body mass index and waist circumference into the clinical assessment may identify the higher risk phenotype of obesity better than each of these parameters alone, especially in those individuals with a lower body mass index [23,24]. In addition to body mass index and waist circumference measurements, a complete medical history to identify the causes of obesity, an adequate physical examination, and relevant laboratory tests will help identify individuals who will benefit from different obesity treatments .
In Canada, for example, the Edmonton Obesity Staging System (EOSS) has been proposed to guide clinical decisions based on the assessment of people living with obesity independently from body mass index [21,26]. This five-stage staging system considers metabolic, physical, and psychological parameters to determine optimal obesity treatment. Population-based studies have shown this scale to be a better predictor of all-cause mortality compared with body mass index or waist circumference measurements alone [27,28]. However, there are still no studies validating this system in the Chilean population.
Obesity treatments should aim at improving health and well-being, not only at losing body weight [28,29]. Multiple studies show that modest weight losses, between 3% and 5% of total weight [30,31,32,33], may be sufficient to improve metabolic parameters in patients living with overweight or obesity. In a pilot lifestyle intervention program among overweight or obese adults at risk for Type 2 diabetes, an approximate 4% weight reduction after four months of intervention achieved significant improvement in fasting glycemia, basal insulinemia, cholesterol, and blood pressure . However, it is now recognized that the treatment approach should be comprehensive and not solely focused on weight. Since the existing literature is mainly based on weight loss outcomes, several recommendations in this guideline focus on this. However, further research is needed to shift the therapeutic focus toward improving health outcomes centered on the patient and their quality of life and not solely on weight loss.
The dominant cultural narrative regarding obesity fuels assumptions about personal irresponsibility, lack of willpower, guilt, and shame . Notably, the stigma of obesity negatively influences the level and quality of care people receive .
Due to the above, we propose using an approach strategy based on five steps to systematize and cover each component of the patient’s history and context to recommend the most suitable treatment.
Step 1: recognizing obesity as a chronic disease and obtaining patient permission
Healthcare professionals should recognize and treat obesity as a chronic disease caused by abnormal or excessive accumulation of body fat (adiposity), which impairs health and is associated with an increased risk of morbidity and premature mortality [1,2,12,37,38,39]. This disease does not present in the same way in all patients and requires individualized treatment and long-term support, just like any other complex chronic disease.
Body weight bias in healthcare can reduce the quality of care for people with obesity . One of the keys to reducing weight-related bias, stigma, and discrimination in healthcare settings is for healthcare professionals to be aware of their own attitudes and behaviors toward people living with obesity .
Healthcare professionals should not assume that all patients are ready to initiate obesity treatment. To assess this, they should ask the patient’s permission to discuss obesity and, if obtained, can begin to discuss relevant assessment and treatment possibilities [41,42].
Step 2: Assessment
A holistic approach focused on healthy behaviors should be promoted, and the underlying causes of weight gain should be addressed, avoiding stigmatizing and overly simplistic narratives.
Direct measurement of height, weight, waist circumference, and calculation of body mass index should be included in the routine physical examination of all adults. Although the body mass index has its limitations, it remains a valuable tool for screening purposes and assessing population health . For individuals with a high body mass index (25 to 34.9 kilograms per square meter), waist circumference should be measured regularly to identify individuals with increased visceral adiposity and related health risks .
The root causes of obesity include biological factors such as genetics, epigenetics, neurohormonal mechanisms, associated chronic diseases, and medications that cause increased adipose tissue and body weight; sociocultural practices and beliefs; social determinants of health; the built environment, individual life experiences such as adverse childhood experiences; and psychological factors such as mood, anxiety, binge eating disorder, attention-deficit/hyperactivity disorder, self-esteem, and identity . Working with individuals to understand their context and culture, and integrating their causes, allows the development of personalized intervention plans. These plans can be integrated into long-term therapeutic relationships for follow-up of obesity and related comorbidities, including addressing the causes of obesity. A complete medical history is recommended to identify these causes and physical, mental, and psychosocial barriers to possible treatments. Physical examination, laboratory, imaging, and other investigations should be performed according to clinical judgment. We also recommend measuring blood pressure in both arms and obtaining fasting glycemia or glycosylated hemoglobin values, a lipid panel to determine cardiometabolic risk, and, when indicated, transaminase levels in conjunction with abdominal ultrasound to detect nonalcoholic fatty liver disease.
Step 3: Discussion of treatment options
People living with obesity should receive individualized care plans that address the root causes and support behavioral change (e.g., nutrition, physical activity) and complementary therapies, which may include psychological, pharmacological, and surgical interventions.
Regardless of body size or composition, all individuals would benefit from adopting a healthy, balanced nutritional plan and regular physical activity. Aerobic activity (30 to 60 minutes) on most days of the week can lead to small weight and fat loss, cardiometabolic parameters improvement, and weight loss maintenance . Weight loss and its maintenance require a long-term reduction in caloric intake. Adherence to a long-term healthy eating pattern personalized to meet individual values, preferences, nutritional needs, and treatment goals is essential in managing health and weight. Nutritional therapy is the basis for treating chronic diseases [46,47]. However, it should not be used without other strategies, as maintaining weight loss can be problematic in the long term. Compensatory mechanisms increase hunger, promote positive caloric intake, and, consequently, weight gain [48,49]. Nutritional therapy, in combination with other interventions (i.e., psychological, pharmacological, surgical), should be tailored to the individual’s health or weight-related outcomes [46,50]. The magnitude of weight loss varies substantially among individuals, depending on biological and psychosocial factors and not simply on individual effort. The weight at which the body stabilizes when engaging in healthy behaviors may be referred to as "optimal” weight and may not be an "ideal" weight on the body mass index scale. Reaching an "ideal" body mass index can be challenging. If weight loss is needed to improve health and well-being beyond what can be achieved with behavioral modification, more intense pharmacologic and surgical therapeutic options may be considered.
All interventions, such as healthy eating and physical activity strategies, medication adherence, or approaches to preparing for and adapting to surgery, are based on behavioral change . Psychological and behavioral interventions are the "how" of change, as they allow the physician to guide the patient toward recommended behaviors that can be maintained over the long term .
We recommend adjunctive pharmacologic therapy for weight loss and weight maintenance for individuals with a body mass index equal to or greater than 30 kilograms per square meter or greater than 27 kilograms per square meter with adiposity-related complications to support nutritional therapy, physical activity, and psychological and surgical interventions. The options available in our country include liraglutide 3 milligrams, the combination of naltrexone and bupropion, orlistat, and phentermine. Pharmacotherapy increases the magnitude of weight loss beyond what health behavior changes alone can achieve and prevents weight regain [53,54,55,56,57].
Bariatric surgery may be considered for individuals with a body mass index equal to or greater than 40 kilograms per square meter or equal to or greater than 35 kilograms per square meter with at least one obesity-related disease and between 30 and 35 kilograms per square meter with Type 2 diabetes mellitus with poor metabolic control despite receiving pharmacologic treatment at maximal doses. The decision on the type of surgery should be made in collaboration with a multidisciplinary team, balancing the patient’s expectations, medical condition, and the expected benefits and risks.
Step 4: agreement on the goals of therapy
Because obesity is a chronic disease, its long-term management involves collaboration between the patient and healthcare professionals . The latter should talk with their patients and agree on realistic expectations, person-centered treatments, and sustainable goals for behavior change and health outcomes . Useful actions in primary care practices to mitigate anti-obesity stigma include explicitly acknowledging the multiple determinants of weight, disrupting stereotypes of personal failure or success linked to body composition, focusing on behavioral treatments to improve overall health, and redefining success as healthy behavior change regardless of body size or weight [60,61].
Step 5: follow-up and advocacy for access
There is a need to advocate for more effective care for people living with obesity. This includes improving health professionals' training and lifelong learning to deliver effective, evidence-based care. There is also a need to support the allocation of healthcare resources to improve access to effective behavioral, pharmacological, and surgical therapeutic options.
None of the medications for the management of obesity available in Chile are covered by the National Health Fund (FONASA), nor by social security health institutions, and only some private insurers cover part of their cost under certain circumstances. The same happened with access to bariatric surgery until, as of March 2022, the Diagnostic Payment Coupon (PAD) system was activated, whereby the National Health Fund will co-pay an amount for gastric bypass and vertical gastrectomy surgeries in the following cases:
Patients between 18 to 65 years old.
Patients with a body mass index greater than 40 kilograms per square meter.
Patients with a body mass index of 35 to 40 kilograms per square meter with comorbidities (one major criterion plus one minor criterion or three minor criteria).
Patients with a body mass index of 30 to 35 kilograms per square meter with difficult-to-manage type two diabetes (or two major and one minor criterion).
The target audience for this guide is health professionals (mainly those working in primary care), people living with obesity, and their families. This guide can also be used by policy-makers, legislators, or decision-makers involved in managing and administering resources for obesity care. This guideline focuses on adult obesity and is intended to be an up-to-date document on inter- and multidisciplinary management, free of stigmatization, including effective and safe treatments according to the available evidence. The clinical recommendations are used as a guide for healthcare professionals. Resource limitations and individual patient preferences may make it challenging to implement all the recommendations, but this guide aims to improve the standard and access to care for people with obesity in all regions of Chile.
The Canadian clinical practice guideline for adult obesity was developed by Obesity Canada and the Canadian Association of Bariatric Physicians and Surgeons and published in August 2020. Given the extensive resources used to develop a clinical practice guideline and the high level of interest in some countries, Obesity Canada developed a pilot project designed to adapt and implement the guideline to local contexts in other countries.
Composition of the group participating in the development of the guideline
In Chile, the project was awarded, after a formal application, to the Chilean Society of Bariatric and Metabolic Surgery. Dr. Yudith Preiss Contreras, a specialist in Clinical Nutrition of Adults, and a member of the Chilean Society of Bariatric and Metabolic Surgery, was in charge of the project’s development. In addition, technical guidance was provided by Dr. Ximena Ramos Salas, Director of Research and Policy at Obesity Canada, who coordinated the development of the guide in Canada, and Miguel Alejandro Saquimux Contreras, research assistant at Obesity Canada.
The Chilean Society of Bariatric and Metabolic Surgery established an Executive Committee made up of four participants: the President and former President of the Chilean Society of Bariatric and Metabolic Surgery, two specialists in the medical and surgical management of obesity, a physician specializing in clinical nutrition of adults, and a bariatric surgeon who also served as secretary of the Chilean Society of Bariatric and Metabolic Surgery: Francisco Pacheco Bastidas, Claudio Canales Ferrada, Yudith Preiss Contreras, and Rodrigo Muñoz Claro, respectively. An Intersocietal Committee was formed to involve the largest number of professionals, scientists, and academics related to the study and management of obesity in our country. This committee included the Chilean Association of Clinical Nutrition, Obesity and Metabolism, the Chilean Society of Family Medicine, the Chilean Society of Neurology, Psychiatry and Neurosurgery, the Chilean Society of Nutrition, the Chilean Society of Sleep Medicine, and the Chilean Society of Gynecology and Obstetrics, whose representatives participated in both the Extended Executive Committee, serving as lead authors of chapters, and/or as external reviewers.
The selection of authors included representatives of the public and private health networks. The number of participating authors per chapter ranged from two to five. In addition, methodological experts were involved in updating the evidence and adapting the guidelines. The entire team of authors, steering committee, independent methodologists, and administrative staff supported the project’s coordination and development. The methodology chapter summarizes the guideline development process and the responsibilities of each participating group.
This process did not involve patients because, in this first stage, it was not possible to implement an administrative structure capable of making an open and transparent call for organizations and/or interested individuals to participate in a meaningful way (availability of time for weekly meetings, full professional competence in English, participation in representative non-governmental organizations, among other criteria). In the future, we hope that we will have the capacity to convene individuals and patient organizations, ensuring an active involvement that reflects their capabilities and contributions when updating this guideline.
Representatives of indigenous peoples did not participate in the project because, in Canada, the specific chapter on indigenous peoples resulted from a research process investigating the perceptions and actions on obesity among these people. This could not be done at this point in the project. The Executive Committee intends to include in a future update a chapter that responds to the realities of the indigenous peoples living in Chile. For the development of this adaptation, the GRADE framework for the adoption, adaptation, and de novo development of reliable recommendations, known as GRADE-ADOLOPMENT , was used as a basis for the guideline developed by Obesity Canada . First, each panel of authors evaluated the recommendations of the original guideline, identifying which recommendations could be adopted after considering all the criteria in the GRADE-EtD framework and evaluating the judgments that led to the final formulation of the original recommendations. Out of 80 original recommendations, 76 were considered for adoption, with no modifications required.
Only one original recommendation was adapted, identifying sufficient judgments to change the strength and direction of the original recommendation.
The final adopted recommendations and adapted recommendations can be seen in Tables 2 and 4, respectively. The complete description of the methodology used can be found in the Methodology chapter of the Chilean Obesity Guidelines.
Secondly, the executive committee carried out a prioritization process of de novo clinical questions considered vital and indispensable for the Chilean guideline and not addressed in the guideline developed for Canada. The Chilean authors submitted 41 potential questions for new recommendations. The panel members finally identified and selected 12 questions to develop de novo recommendations. Therefore, a new search, selection, and synthesis of the evidence were performed.
Literature review and assessment of the certainty of the evidence
Systematic reviews were searched on the L-OVE (Living OVerview of Evidence, available at
An iterative process was carried out among the panel members, involving the leaders and authors of the different chapters. For each of the 12 recommendations, the methodological team of the Epistemonikos Foundation performed the evidence profiles and the evaluation of their quality. The GRADE-EtD framework  was used for the clinical recommendations, allowing for a structured consensus process and transparent documentation of all participant judgments.
Chapter leaders and participants voted on each new question to ensure consensus by evaluating the evidence supporting each question. The certainty of the evidence was assessed using the GRADE approach, which defines certainty as the degree of confidence that the estimate of an effect is adequate to support a given decision or recommendation . This is classified as "high," "moderate," "low," or "very low" depending on the evidence available for each guideline question. The strength of a recommendation can be strong, or conditional (also known as weak). Understanding this interpretation is essential for decision-making .
For the final wording of the recommendations, the panel made a consensus of judgments that allowed the strength and direction of each recommendation to be determined, reflecting the degree of confidence held about the desirable or undesirable effects of each intervention. The recommendations were categorized as strong or weak according to the certainty of the evidence and the effect they have on important outcomes. The steering committee, chapter leaders, and authors formulated the recommendations based on the highest level of evidence available (Table 3).
Only one original recommendation was adapted, identifying local evidence linked to the cost and accessibility of the intervention sufficient to change the original recommendation’s strength and direction, maintaining the evidence’s level of certainty but decreasing the strength of the recommendation (Table 4).
The new recommendations, along with the adapted recommendation, are described in Table 4. A full description of the evidence supporting the final recommendations can be found as supplementary material in "Summary and Synthesis of Evidence." These recommendations were not reviewed or approved by the original Canadian guideline committee.
Dissemination and implementation
This guideline is intended to remain a living document that is constantly updated and allows patients, professionals, and health policy decision-makers to have a tool based on the best available evidence to define support mechanisms for prevention and cost-effective and safe treatments. For this purpose, an independent web page (
The implementation of this guide will depend on the reception of health authorities, the allocation of resources for the training of health professionals, and calls to action from patient and family organizations.
Obesity is a chronic, multifactorial, progressive, and relapsing disease. People living with obesity often suffer from stigmatization and blame, increasing the access gap and worsening health outcomes. This paper demonstrates advances in understanding the pathophysiology, health determinants, assessment, and treatment of obesity. It also seeks to redirect the multidisciplinary management approach toward stigma-free care and to focus outcomes on patient quality of life rather than solely on weight loss.