Clinical Guide for the General Gastroenterologist on the Assessment and Management of Obesity

Researchers outlined clinical tools for the evaluation and management of obesity in general gastroenterology practice.

Researchers released a clinical guide for the general gastroenterologist on the assessment and management of obesity, which was published in the American Journal of Gastroenterology. With rates of obesity on the rise, clinicians will continue to encounter more patients with this complex disease. These patients are associated with an increased risk for gastrointestinal (GI) comorbidities. For this reason, it is imperative that gastroenterologists are equipped with the clinical tools needed to address obesity.

It is estimated that over 650 million adults (13% worldwide) have obesity. The prevalence of obesity is even higher in the United States (US), with approximately 42.4% of adults meeting the criteria for obesity. In 2013, the American Medical Association officially recognized obesity as a chronic disease. The Obesity Medicine Association has defined obesity as, “a chronic, relapsing, multifactorial, and neurobehavioral disease, wherein an increase in body fat promotes adipose tissue dysfunction and abnormal fat mass physical forces, resulting in adverse metabolic, bio-mechanical, and psychosocial health consequences.” Obesity has traditionally been defined as a body mass index (BMI) of at least 30 kg/m2.

Obesity-Related Gastrointestinal Conditions

Obesity is known to be associated with several GI conditions including various esophageal, gastric, small intestinal, colonic, hepatobiliary, and pancreatic diseases. According to the authors, obesity may result in a higher incidence, earlier presentation, and more severe clinical manifestations of these diseases. The early diagnosis of obesity along with timely evaluation and management may help reduce the frequency and severity of obesity-related GI conditions. 

Obesity Evaluation

The obesity evaluation consists of the following elements: medical, lifestyle, psychological, endoscopic, and other.

During the initial evaluation, the authors recommend that physicians should assess patients’ readiness to change their health behavior utilizing the “Stages of Change” model. The model consist of 5 stages: precontemplation, contemplation, preparation, action, and maintenance.

During the medical evaluation, a weight-focused history, physical examination, and laboratory evaluation should be obtained. BMI, waist circumference, waist-hip ratio, and body fat percentage should be measured on the physical examination. Certain medications are associated with weight gain. These medications should be titrated down or substituted with weight neutral drugs.  

During the lifestyle evaluation, dietary and eating habits should be reviewed using a 24-hour diet recall, food frequency questionnaire, or food log. The physical lifestyle of the patient should also be assessed. Physicians should be aware of patients’ lifestyle and habits regarding exercise.

During the psychological evaluation, it is important that psychiatric history is examined. Evaluating psychological history may uncover eating disorders. Clinicians should assess whether patients suffer from bulimia nervosa, binge eating disorder, purging disorder, and night eating syndrome. If one of these aforementioned eating disorders is identified, the patient needs to be referred to a mental health specialist.   

Endoscopy may be needed as part of the initial evaluation for certain patients with obesity. For patients who are undergoing bariatric surgery, the International Federation for the Surgery of Obesity and Metabolic Disorders recommends that a preoperative esophagogastroduodenoscopy should be considered for all patients with and without GI symptoms.

Subsequent to the initial evaluation, additional studies, such as direct/indirect calorimetry, Homeostatic Model Assessment of Insulin Resistance, liver ultrasound with elastography, and magnetic resonance elastography, may be obtained on a case by case basis. The researchers suggest that referral to appropriate specialists for signs or symptoms of non-GI obesity-related comorbidities should be considered.

Obesity Management

The spectrum of obesity treatment options include the following: lifestyle modification (LM), pharmacotherapy, bariatric endoscopy, and bariatric surgery.

The investigators note that LM is considered a first-line therapy for the treatment of obesity and the 3 primary components are diet, exercise, and behavioral therapy. An energy deficit is necessary to achieve weight loss. This can be accomplished by lowering caloric intake or limiting certain types of food.  

Physical activity is considered a key component of a weight loss program. The authors recommend at least 150 minutes of aerobic activity per week. This regimen should be completed at least 30 minutes per day, most days of the week, with at least 2 resistance training days per week (minimum of 1 set of 8–12 repetitions for a total of 8–10 exercises per week). The authors report that, “Resistance training is important because it helps improve muscle strength and endurance, modify coronary risk factors, and preserve fat-free mass during weight loss to enhance metabolic rate.” Higher levels of physical activity of 200 to 300 minutes are recommended during the weight maintenance phase.

Behavior therapy is also recommended, as it targets maladaptive eating behaviors, activity, and thinking habits that contribute to obesity.

Overall, a comprehensive LM program should be implemented in every weight loss intervention. The researchers assert that the key components to success include adherence to an appropriate diet plan, incorporation of physical activity, and behavioral treatment that provides the necessary strategies to maintain the weight loss.

When patients fail to respond to LMs and have a BMI of >30 or >27 kg/m2 with obesity-related comorbidities, weight loss medications may be considered. It is important to review current medications the patient is taking before prescribing a weight loss medication. If any medications are associated with weight gain, they should be substituted with more weight-neutral medications.

The investigators suggest that bariatric endoscopy may be divided into gastric and small bowel interventions. Gastric interventions primarily generate weight loss with secondary effects on metabolic conditions. In contrast, small bowel interventions have direct effects on metabolic conditions, regardless of whether or not weight loss occurs.  

For patients with a BMI of >40 or >35 kg/m2 with at least 1 comorbidity, bariatric surgery should be considered. Sleeve gastrectomy and Roux-en-Y gastric bypass are the most commonly performed bariatric surgical procedure. However, Roux-en-Y gastric bypass is considered the preferred surgery for patients with obesity and concomitant metabolic disease or gastroesophageal reflux disease.

Endoscopic Management of Bariatric Surgical Complications  

As the number of bariatric surgeries continue to increase, gastroenterologists should strive to better understand the potential complications associated with this surgery. If weight regain occurs, the authors recommend that the patient be referred to a multidisciplinary team for consideration of pharmacotherapy and/or endoscopic revision of bariatric surgery. This multidisciplinary team includes a dietitian, obesity medicine expert, bariatric endoscopist, and bariatric surgeon.

Developing Expertise in Obesity Medicine and Bariatric Endoscopy

The authors state, “There are several resources available for gastroenterologists who plan on specializing in Obesity Medicine and Bariatric Endoscopy. These programs focus on cognitive elements, skill set development, and center requirements.” Without the need for additional training, the American Board of Obesity Medicine credentialing is also available for board-certified gastroenterologists.

From a center standpoint, the researchers propose a patient-friendly waiting area (including accommodations such as wide chairs and reinforced toilets) and medical equipment (such as extra-large blood pressure cuffs and bariatric scales). Staff training is also encouraged to reduce bias and stigma. The investigators assert that a multidisciplinary team is considered essential for the treatment of obesity. This multidisciplinary team should include bariatric surgeons, bariatric endoscopists, obesity medicine experts, dietitians, psychologists, health coaches, and/or social workers.


With increasing rates of obesity, it is inevitable that physicians will see more patients with this chronic condition. These patients are at greater risk for GI comorbidities and subsequently necessitate special consideration. Given the association between obesity and several GI conditions, gastroenterologists can play a vital role in the management of this disease.

Disclosure: The study authors declared affiliations with the industry. Please see the original reference for a full list of authors’ disclosures.

Disclosure: This research was supported by multiple sources. Please see the original reference for a full list of disclosures.


Jirapinyo P, Thompson CC. Obesity primer for the practicing gastroenterologist. Am J Gastroenterol. Published online in April 6, 2021. doi: 10.14309/ajg.0000000000001200