SUMMARY 

Obesity is a chronic, relapsing, and multifactorial disease that is defined by the CDC as a weight that is higher than what is considered healthy for a given height. The prevalence of obesity has been increasing over several decades with roughly two thirds of adults considered obese or overweight, and a recent estimate puts the prevalence of adults with obesity at nearly 42% of the population. Obesity, as defined by BMI, is not enough to qualify a patient’s health status. Healthcare providers should combine appropriate clinical assessments, taking into account body weight, central fat distribution, functional status, and presence of obesity related complications, to create a more accurate picture of a patient’s health. While first line therapy for obesity remains lifestyle interventions with or without medication assistance, several surgical and endoscopic procedures are also available to assist patients in their weight loss goals. The American Gastroenterology Association released their guideline on obesity management in 2017, with surgical and endoscopic management recommendations summarized below. For the most recent AGA guidelines on pharmacologic management of obesity, please see further reading below.  

Obesity Diagnosis 

• All adults should be screened for obesity by obtaining a height and weight and calculating BMI during a routine physical exam  
• BMI is calculated by dividing weight (kg) over height (m)² 
  • Underweight: <18.5 kg/m ² 
  • Normal weight: ≥18.5 to 24.9 kg/m ² 
  • Overweight:  ≥25.0 to 29.9 kg/m ² 
  • Obesity:  ≥30 kg/m ² 
• Obesity can be further characterized by class 
  • Class I: 30.0 to 34.9 kg/m ² 
  • Class II: 35.0 to 39.9 kg/m ²  
  • Class III:  ≥40 kg/m ² 
• A BMI over 25 kg/m ² should prompt further evaluation including  
  • Measurement of waist circumference: > 40 inches in men and > 35 inches in women is associated with increased risk for obesity related complications 
  • Screening for obesity related complications (see below) 
  • Consideration of causes of weight gain not related to diet and activity level (e.g., hypothyroidism, drug side effect, depression, Cushing’s syndrome)  
  • Blood pressure measurement  
  • Fasting glucose and lipid levels 

Note: A BMI > 23 kg/m² may indicate the need for further evaluation in patients of South Asian, Southeast Asian, and East Asian descent as obesity related complications develop at lower BMIs in these populations 

 Obesity related complications 

• Type 2 Diabetes Mellitus (T2DM), Prediabetes  
• Cardiovascular disease 
• Hypertension 
• Hyperlipidemia 
• Obstructive sleep apnea 
• Obesity hypoventilation syndrome 
• Nonalcoholic fatty liver disease 
• Osteoarthritis 
• Stroke 
• Certain malignancies (e.g., colorectal cancer, endometrial cancer)  
• Depression  
• PCOS, Infertility  
• GERD  
• Urinary incontinence  
• VTE 

• Gallstones 

Management Options 

Bariatric Endoscopy 

The AGA recommends considering bariatric endoscopy in combination with lifestyle changes for patients unable to lose or maintain weight loss with diet and exercise alone. Patients will require an associated 
multidisciplinary weight loss program for success, typically including gastroenterologists, obesity medicine specialists, dietitians, psychologists, primary care doctors and exercise specialists. 

• Intragastric balloon 
  • Obrera: Single balloon filled with saline | Placed for 6 months | Approved for those with BMI of 30 to 40 kg/m² with or without an obesity related complication  
  • Reshape Duo: Double balloon system | Placed for 6 months | Approved for those with BMI of 30 to 40 kg/m² and at least one obesity related complication 
• Aspiration therapy  
  • The AspireAssist Aspiration Therapy System: Percutaneously placed gastrostomy tube to assist with removal of gastric contents after eating | For patients >21 years old | BMI of 35 to 55 kg/m² | Have failed nonsurgical weight loss therapy  
• Endoscopic sleeve gastroplasty  
  • Sutures placed endoscopically through the gastric wall from the prepyloric antrum to the gastroesophageal junction create a sleeve by reducing the greater curvature of the stomach 
  • FDA approved device designed for this procedure is approved for patients with a BMI of 30 to 50 kg/m² who have been unable to maintain weight loss through more conservative measures  
• Transoral outlet reduction (TORe) 
  • For patients who have regained weight following Roux-en-Y gastric bypass 
  • Uses an endoscopic suturing device to reduce the gastrojejunal anastomotic opening by placement of a suture around the anastomosis 

Bariatric Surgery 

Indicated for patients with a BMI > 40 kg/m² or a BMI > 35 kg/m² with one obesity related complication who have failed prior attempts at medical weight loss. Similar to endoscopy interventions, long term success requires a multidisciplinary weight loss program. In addition to successful weight loss, bariatric surgery has been shown to improve or resolve obesity related complications such as DM2, OSA, NASH, and hypertension.  

• Laparoscopic sleeve gastrectomy  
  • Most performed procedure  
  • Removes two thirds to three fourths of the stomach leaving a tubularized conduit  
  • Stomach diminished capacity leads to early satiety and decreased calorie intake 
  • Removal of gastric fundus also causes hormonal changes that contribute to weight loss  
  • Relative contraindications include history of Barrett’s esophagus and refractory GERD 
• Laparoscopic Roux-en-Y gastric bypass  
  • Creation of a small gastric pouch with mid-jejunum roux limb attached, creating a bypass of the duodenum and proximal jejunum  
  • Successful weight loss is due to both a restrictive and malabsorptive effect of the surgery 
  • Typically leads to more weight loss than sleeve gastrectomy  
  • Contraindicated in patients with IBD or diseases that would be affected by altered absorption (e.g., post-transplant patients on immunosuppression) 
• Adjustable gastric banding 
  • Laparoscopically placed soft silicone ring just distal to the esophagogastric junction 
  • Ring includes a balloon that can be filled via a percutaneous port to induce fullness  
  • Performance rates of this procedure have fallen dramatically due to less associated weight loss compared to other procedures and increased long term complications  
  • Contraindications include large hiatal hernia |Severe GERD | Esophageal motility 
    disorders 

Follow Up Care  

At least yearly follow-up is needed to assess for weight regain and exclude nutrient, vitamin, or micronutrient deficiencies 

Nutritional deficiencies to monitor 

Iron | B12 | Folate | Copper | Selenium | Thiamine | Calcium | Vitamins A, C, D, E, K | Zinc | Protein 

Primary Sources – Learn More: 

White Paper AGA: POWER — Practice Guide on Obesity and Weight Management, Education, and Resources 

Expert Review: Long term outcomes of metabolic/bariatric surgery in adults