Obesity Primer for the Practicing Gastroenterologist ...

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Obesity Primer for the Practicing GastroenterologistPichamol Jirapinyo, MD, MPH1,2 and Christopher C. Thompson, MD, MSc1,2

With worsening of the obesity pandemic, gastroenterologists will see more patients with this chronic disease. Given the

association between obesity and several gastrointestinal conditions and the interplay between obesity pathophysiology and

gut hormones, gastroenterologists canplayan important role in themanagement of this disease.Furthermore, becausemore

patients undergo bariatric surgery, an understanding of postsurgical anatomy andmedical and endoscopic management of

bariatric surgical complications is essential. This article provides clinical tools for the assessment and management of

obesity for the general gastroenterologist. Tables containing high-yield practical information are also provided for quick

reference.

Am J Gastroenterol 2021;116:918–934. https://doi.org/10.14309/ajg.0000000000001200

INTRODUCTIONObesity has become pandemic. It is estimated that more than 650million adults (13% worldwide) suffer from obesity (1). In theUnited States, the prevalence is even higher with 42.4% of adultsmeeting criteria for obesity (2). As of 2013, the AmericanMedicalAssociation officially recognized obesity as a chronic disease (3).

There are several ways to define and categorize obesity. Per theObesity Medicine Association, obesity is “a chronic, relapsing,multifactorial, and neurobehavioral disease, wherein an increase inbody fat promotes adipose tissue dysfunction and abnormal fatmass physical forces, resulting in adverse metabolic, bio-mechanical, and psychosocial health consequences (4).” Tradi-tionally, obesity has also been defined as a body mass index (BMI)of at least 30kg/m2. It is further categorized into class I obesity (BMI30–34.9 kg/m2), class II obesity (BMI 35–39.9 kg/m2), and class IIIobesity (BMI$40 kg/m2) (5). The use of BMI, however, is limitedin certain populations, such as the elderly, muscular, and sarco-penic, because it does not distinguish between lean muscle andbody fat or its location (6). Alternatively, waist circumference(WC)may be used. Specifically, for patients with a BMI of 25–34.9kg/m2,WCof$40 inches (.102 cm) inmen and$35 inches (.88cm) in women suggest central obesity, which is associated withincreased cardiometabolic risk (7–9). Finally, obesity may also bedefined as body fat percentageof$ 25% inmenand 35% inwomenwith the healthy body fat ranging from 8% to 19% in men and21%–35% in women (depending on age) (4,10,11). Nevertheless,accurate body composition testing can be expensive with limitedavailability. Furthermore, it is important to note that these cutoffsvarybased on ethnicity, such as aBMIof$25and$27kg/m2 beingused to define obesity in Asian and Middle East populations, re-spectively, because of their higher body fat at a lower BMI andearlier appearance of comorbidities (12,13).

This review is intended to serve as a clinical guide for thegeneral gastroenterologist on the assessment and management ofobesity. Tables containing high-yield information are also pro-vided for quick reference.

OBESITY-RELATED GASTROINTESTINAL CONDITIONSObesity is associated with several gastrointestinal (GI) conditionsincluding various esophageal, gastric, small intestinal, colonic,hepatobiliary, and pancreatic diseases (14–17). Specifically, obe-sity may result in a higher incidence, earlier presentation, andmore severe clinical manifestations of these diseases. For exam-ple, obesity increases the risk of gastroesophageal reflux disease,esophagitis, and esophageal adenocarcinoma by 2-, 1.8-, and 2.8-fold, respectively (18). Similarly, the incidence of nonalcoholicfatty liver disease is approximately 90% in patients with obesity,compared with 25% in the general population (19), and obesityhas been shown to hasten the progression from compensated todecompensated cirrhosis (20). However, weight loss of at least7%–10% total weight loss (TWL) has been shown to reversehistologic features of fatty liver (21). A more extensive list ofobesity-relatedGI conditions is summarized inTable 1 and can bemore deeply explored in the work of Camilleri et al. (14). Giventhese associations, gastroenterologists should have an increasedsuspicion and low threshold to look for these illnesses in thispatient population. In addition, early diagnosis of obesity andtimely evaluation and management may help reduce the preva-lence and severity of such disorders.

OBESITY EVALUATIONThe obesity evaluation consists of several elements includingmedical, lifestyle, psychological, and endoscopic assessments.

Initial evaluation

During the initial encounter, physicians should assess patients’readiness to change their health behavior using the “Stages ofChange” model (22,23). Specifically, the model consists of 5stages: (i) precontemplation: the individual is unaware of theconsequences of their behavior and resistant to change, (ii)contemplation: the individual is aware of the consequences andopen to change, (iii) preparation: the individual shows

1Division of Gastroenterology, Hepatology and Endoscopy, Brigham and Women’s Hospital, Boston, Massachusetts, USA; 2Harvard Medical School, Boston,Massachusetts, USA. Correspondence: Christopher C. Thompson, MD, MSc. E-mail: [email protected] June 4, 2020; accepted December 29, 2020; published online April 6, 2021

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anticipation and willingness to change within the next 6 months,(iv) action: the individual is in the process of changing their be-havior, and (v)maintenance: the individual has sustained the newbehavior for more than 6 months. For patients in the

precontemplation stage, the goal is to help move them to thecontemplation stage before referral to bariatric specialists. Mo-tivational interviewing techniques, such as the 5 A’s (Ask, Advise,Assess, Assist, and Arrange) and OARS (Open-ended questions,Affirmations, Reflections, and Summaries), can help with thisprocess to elicit and strengthen patient’s motivation along thisspectrum (24,25).

Medical evaluation

A weight-focused history, physical examination, and laboratoryevaluation should be obtained. Weights at specific time points,including around the major life events, and the effectiveness ofprevious weight loss attempts should be reviewed. Certain med-ications can cause weight gain and should be downtitrated orsubstituted with weight neutral drugs (Table 2) (26,27). Onphysical examination, BMI, WC, waist-hip ratio, and percentbody fat should be measured. Signs of obesity-associated medicalconditions including hyperpigmented skin around the neck oraxilla (acanthosis nigricans associated with insulin resistance),hirsutism (polycystic ovarian syndrome), large neck circumfer-ence (.17 inches for men or .16 inches for women suggestingincreased risk of sleep apnea), and thin, atrophic skin (Cushingdisease) should be looked for (28). Baseline laboratory shouldinclude electrolytes, renal function, fasting glucose, hemoglobinA1c (HbA1c), liver enzymes, complete blood count, lipid panel,thyroid-stimulating hormone, vitamin D, and urine albumin.

Lifestyle evaluation

Dietary and eating habits should be reviewed using a 24-hour dietrecall, food frequency questionnaire, or food log. Dietary habitsincluding eating patterns (skipping breakfast, eating one largemeal per day, emotional eating, and grazing), frequency of eatingout, and grocery shopping details should be evaluated. Further-more, onset of satiation (the point at which one becomes fullending one’s desire to eat during a single meal) and period ofsatiety (the state of being full and satisfied which regulates thetime elapsed between 2 meals) should be assessed.

Physical lifestyle should be assessed. It is important to un-derstand whether patients have an active or sedentary lifestyleand details regarding exercise (types, duration, and frequency).Total energy expenditure (TEE) is the amount of calories burnedper day. It is composed of resting energy expenditure (REE),thermic effect of meals (TEM), and energy expenditure fromphysical activity (EEPA), which is further broken down into ex-ercise and nonexercise activity thermogenesis (NEAT).

TEE ¼ REE ð60%2 75%Þ1TEM ð10%Þ1 ½exercise1NEAT� ð15%2 30%Þ

REE is the energy cost of physiological functions at rest, suchas respiration, cardiac output, and body temperature regulation.TEM is the energy required for digestion, absorption, and dis-posal of ingested nutrients. Its magnitude depends on macro-nutrient composition with proteins requiring the most energy(20%–35% of energy consumed), followed by carbohydrates(5%–15%) and fats (5%–15%) (29,30). EEPA consists of exerciseandNEAT,which is the energy expended for physical activity thatis not sleeping, eating, or exercise. As shown in the equation,changing one’s lifestyle directly affects EEPA, resulting in changesin TEE and daily net calories.

Table 1. Gastrointestinal conditions associated with obesity

Gastrointestinal

organ

Gastrointestinal conditions

associated with obesity

Esophagus •Abnormal esophageal peristalsis

•Isolated hypertensive LES pressure

•Isolated hypotensive LES pressure

•GERD•Erosive esophagitis•Barrett’s esophagus•Esophageal adenocarcinoma

Stomach •Dyspepsia•Erosive gastritis•Gastric ulcer

•Gastric cancer

•Greater fasting gastric volume

•Decreased satiation

Small intestine •Duodenal ulcer•Small intestinal bacterial overgrowth

•Diarrhea (related to changes in bile acids,

accelerated colonic transit, and increased mucosal

permeability)

•Increased absorption of glucose (related to increasedSGLT-1)

•Increased absorption of protein (specifically whey

hydrolysate)

•Increased absorption of long chain fatty acids (relatedto increased induction of lipid binding proteins)

Colon •Diverticulosis•Diverticular bleeding•Recurrent diverticulitis•Clostridium difficile infection

•Adenomatous polyps

•Sessile serrated polyps

•Colorectal cancer•Dyssynergic defecation•Incomplete rectal evacuation

•Fecal incontinence•Crohn’s disease (conflicting data)

•Earlier loss of response to biologics in IBD patients

Liver •Nonalcoholic fatty liver disease

•Nonalcoholic steatohepatitis

•Cirrhosis•Hepatocellular carcinoma

Biliary •Cholelithiasis•Cholecystitis•Cholesterolosis•Gallbladder cancer

Pancreas •Acute pancreatitis

•Pancreatic cancer

GERD, gastroesophageal reflux disease; IBD, inflammatory bowel disease; LES,lower esophageal sphincter; SGLT-1, sodium glucose linked transporter-1.

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Obesity Primer 919


Psychological evaluation

Psychiatric history including anxiety, depression, and post-traumaticstress disorder shouldbe assessedbecause thismay translate into eatingdisorders. It is important to assesswhether patients suffer frombulimianervosa (recurrent episodes of binge eating 1 inappropriate com-pensatory behavior to prevent weight gain), binge eating disorder(recurrent episodes of binge eating without compensatory behavior),purging disorder (recurrent purging behavior without binge eating),andnight eating syndrome (recurrent episodesofnight eating) becausethese require referral to amental health specialist (31). Physiciansmayconsider using the Eating Disorder Examination Questionnaire forscreening purposes (Table 3) (32,33).

Endoscopic evaluation

Endoscopy may be required as part of the initial evaluation for asubgroup of patients with obesity. In addition, for those who areundergoing bariatric surgery, the International Federation for theSurgery of Obesity and Metabolic Disorders recommends that apreoperative esophagogastroduodenoscopy should be considered forall patients with and without GI symptoms (34). During this

procedure, one shouldnote thepresenceof a hiatal hernia (HillGradeI–IV), esophagitis, Barrett’s esophagus, gastric polyps, gastritis, Hel-icobacter pylori infection, and malignancy. According the systematicreview and meta-analysis conducted by the International Federationfor the Surgery of Obesity and Metabolic Disorders task force (63studies/22495 patients), abnormal esophagogastroduodenoscopyfindings are likely to be found in at least 55.5% of patients beforebariatric surgery (25.3% for a subgroup of asymptomatic patients)with 16.5% having findings that led to modification or delay of theplanned procedure and 0.2% having surgery cancelled (34).

Gastroenterologists should also be familiar with postbariatric sur-gical anatomy including normal and abnormal endoscopic findings.For Roux-en-Y gastric bypass (RYGB), the pouch and gastrojejunalanastomotic sizes shouldbeassessed.Thepresence, location, andsizeofmarginal ulceration and gastrogastric fistula should be documented.For sleeve gastrectomy (SG), the sleeve dimension/configuration andthe presence of sleeve stenosis and/or angulation should be assessed.Furthermore, given the prevalence of de novo reflux (23%) after SG,gastroenterologists should be vigilant in assessing for the presence ofesophagitis (found in up to 53%) and Barrett’s esophagus (found in

Table 2. Medications associated with weight gain, weight neutrality, and weight loss

Medication type Weight gain Weight neutral Weight loss

Antihypertensives Alpha-blockers

• Prazosin• Doxazosin• Terazosin Beta-blockers

• Atenolol• Metoprolol

• Nadolol• Propranolol

ACE inhibitors, ARBs

Beta-blockers

• Carvedilol• NebivololCalcium channel blockers

Thiazides

Antidiabetics Insulin, Meglitinides, Sulfonylureas,

Thiazolidinediones

Alpha-glucosidase inhibitors, Bromocriptine,

Colesevelam, DPP-4 inhibitors

GLP-1 agonists, Metformin,

Pramlintide, SGLT2 inhibitors

Antidepressants MAOIs, Mirtazapine SSRIs

• Citalopram• Paroxetine TCAs

SSRIs

• Fluoxetine• Sertraline

Bupropion

Antipsychotics Clozapine, Lithium Olanzapine,

Quetiapine Risperidone

Aripiprazole, Lurasidone, Ziprasidone

Anticonvulsants Carbamazepine Gabapentin,

Pregabalin, Valproic acid

Lamotrigine, Levetiracetam, Phenytoin Topiramate, Zonisamide

Contraceptives Progestin Barrier methods, Intrauterine device,

Surgical sterilization

Antihistamines First-generation antihistamines

• Diphenhydramine

• Hydroxyzine• Meclizine

Second-generation antihistamines

• Cetirizine• LoratidineThird-generation anti-histamines

• FexofenadineAlternative class of medications

• Decongestants

Steroids Glucocorticoids Inhaled steroids Topical steroids Alternative

classes of medications

• NSAIDs• DMARDs

ACE, angiotensin-converting enzyme; ARB, angiotensin II receptor blockers; DMARD, disease-modifying antirheumatic drug; DPP-4, dipeptidyl peptidase-4; GLP-1,glucagon-like peptide-1; MAOI, monoamine oxidase inhibitor; NSAID, nonsteroidal anti-inflammatory drug; SGLT2, sodium-glucose co-transporter 2; SSRI, selectiveserotonin reuptake inhibitor; TCA, tricyclic antidepressants.


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Table 3. Eating Disorder Examination Questionnaire (EDE-Q) (32,33))

Eating Questionnaire

Instructions: The following questions are concerned with the past 4 wk (28 d) only. Please read each question carefully. Please answer all of the questions. Please only choose one answer for each question.

Thank you.

Questions 1 to 12: Please circle the appropriate number on the right. Remember that the questions only refer to the past 4 wk (28 d) only.

On how many of the past 28 d … No days 1–5 d 6–12 d 13–15 d 16–22 d 23–27 d Every day

1. Have you been deliberately trying to limit the amount of

food you eat to influence your shape or weight (whether or

not you have succeeded)?

0 1 2 3 4 5 6

2. Have you gone for long periods of time (8 waking hours or

more) without eating anything at all in order to influence your

shape or weight?

0 1 2 3 4 5 6

3. Have you tried to exclude from your diet and foods that

you like in order to influence your shape or weight (whether

or not you have succeeded)?

0 1 2 3 4 5 6

4. Have you tried to follow definite rules regarding your

eating (e.g., a calorie limit) in order to influence your shape

or weight (whether or not you have succeeded)?

0 1 2 3 4 5 6

5. Have you had a definite desire to have an empty stomach

with the aim of influencing your shape or weight?

0 1 2 3 4 5 6

6. Have you had a definite desire to have a totally flat

stomach?

0 1 2 3 4 5 6

7. Has thinking about food, eating or calories made it very

difficult to concentrate on things you are interested in (e.g.,

working, following a conversation, or reading)?

0 1 2 3 4 5 6

8. Has thinking about shape or weight made it very difficult

to concentrate on things you are interested in (e.g., working,

following a conversation, or reading)?

0 1 2 3 4 5 6

9. Have you had a definite fear of losing control over eating? 0 1 2 3 4 5 6

10. Have you had a definite fear that you might gain weight? 0 1 2 3 4 5 6

11. Have you felt fat? 0 1 2 3 4 5 6

12. Have you had a strong desire to lose weight? 0 1 2 3 4 5 6

Questions 13 to 18: Please fill in the appropriate number in the boxes on the right. Remember that the questions only refer to the past 4 wk (28 d).Over the past 4 wk (28 d)…

13. Over the past 28 d, how many times have you eaten what other people would regard as an unusually large amount of food (given the circumstances)? ………………

14. On how many of these times did you have a sense of having lost control over your eating (at the time that you were eating)? ………………

15. Over the past 28 d, on howmany DAYS have such episodes of overeating occurred (i.e., you have eaten an unusually large amount of food and have had a sense of

loss of control at the time)?

………………

16. Over the past 28 d, how many times have you made yourself sick (vomit) as a means of controlling your shape or weight? ………………

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Table 3. (continued)

17. Over the past 28 d, how many times have you taken laxatives as a means of controlling your shape or weight? ………………

18. Over the past 28 d, howmany times have you exercised in a “driven” or “compulsive”way as ameans of controlling your weight, shape or amount of fat, or to burn

off calories?

………………

Questions 19 to 21: Please circle the appropriate number. Please note that for these questions the term “binge eating”means eating what others would regard as an unusually large amount of food for the

circumstances, accompanied by a sense of having lost control over eating.

19. Over the past 28 d, on how many days

have you eaten in secret (i.e. furtively)?

… Do not count episodes of binge eating

No days 1–5 d 6–12 d 13–15 d 16–22 d 23–27 d Every day0 1 2 3 4 5 6

20. On what proportion of the times that you have

eaten have you felt guilty (felt that you’ve donewrong)

because of its effect on your shape or weight?…

Do not count episodes of binge eating

None of the

times

A few of

the

times

Less than half Half of the

times

More than half Most of the time Every time

0 1 2 3 4 5 6

21. Over the past 28 d, how concerned have you

been about other people seeing you eat?…

Do not count episodes of binge eating

Not at all Slightly Moderately Markedly0 1 2 3 4 5 6

Questions 22 to 28: Please circle the appropriate number on the right. Remember that the questions only refer to the past 4 wk (28 d).

Over the past 28 d … Not at all Slightly Moderately Markedly

22. Has your weight influenced how you think about (judge)

yourself as a person?

0 1 2 3 4 5 6

23. Has your shape influenced how you think about (judge)

yourself as a person?

0 1 2 3 4 5 6

24. How much would it have upset you if you had been

asked toweigh yourself once aweek (nomore, or less, often)

for the next four weeks?

0 1 2 3 4 5 6

25. How dissatisfied have you been with your weight? 0 1 2 3 4 5 6

26. How dissatisfied have you been with your shape? 0 1 2 3 4 5 6

27. How uncomfortable have you felt seeing your body (e.g,

seeing your shape in themirror, in a shop window reflection,

while undressing or taking a bath or shower)?

0 1 2 3 4 5 6

28. How uncomfortable have you felt about others seeing

your shape or figure (e.g., in communal changing rooms,

when swimming, or wearing tight clothes)?

0 1 2 3 4 5 6

What is your weight at present? (Please give your best estimate.) …………………….

What is your height? (Please give your best estimate.) …………………….

If female: Over the past 3-to-4 mo have you missed any menstrual periods? …………………….

If so, how many? …………………….

Have you been taking the “pill”? …………………….

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Table 4. Dietary interventions for weight loss

Dietary plans Description

Energy focused

Low calorie diet • 1,200–1,600 kcal/d

Very low calorie diet •#800 kcal/d

• Prescribed for #16 wk

Protein-sparing modified fast •#800 kcal/d

• High protein (1.5 g protein/kg ideal body weight)

• Low carbohydrate (,20 g of carbohydrate per day)

• Fat restricted to the protein source

• Prescribed for #6 mo

Meal replacement • Use of liquid shakes and/or bars with a known amount of energy and

macronutrient content to replace 1–3 meals

Macronutrient focused

Low carbohydrate diet •,20% of total energy intake from carbohydrate

Low dlycemic index diet • Replace high GI diet (GI $55) with low GI diet (GI ,55)

Low fat diet •,15%–20% of total energy intake from fat

High protein •$20%–30% of total energy intake from protein

Dietary pattern focused

Atkins diet • Low carbohydrate (,20 g of carbohydrate per day; may increase to 50 g

after 2 wk)

• High protein

• High fat

Ketogenic diet • Low carbohydrate (,20 g of carbohydrate per day)

• Moderate protein (10%–20% of total energy intake from protein)

• High fat

DASH diet • Complex carbohydrate

• Lean protein (avoid red meat)

• Low-fat dairy products as the primary source of fat

• Emphasis on fruits and vegetables

Mediterranean diet • Complex carbohydrate

• Fish and poultry as the primary sources of

protein (avoid red meat)

• Olive oil as the primary source of fat

• Emphasis on plant-based food (fruits, vegetables,

grains, nuts, seeds)

Ornish diet • Vegetarian Diet

• Very low fat (,10% of total energy intake from fat)

Paleolithic diet • Emphasis on fruits, vegetables, nuts, seeds, lean meat, fish

• Avoid grains, legumes, dairy products, processed food

Zone diet • 40% of total energy intake from carbohydrate

• 30% of total energy intake from protein

• 30% of total energy intake from fat

Vegan diet • Exclusion of all animal products and byproducts

Vegetarian diet • Exclusion of all animal products

Dietary-timing focused

Intermittent fasting

Alternate-day fasting

Modified dlternate-day fasting

5:2 Intermittent fasting

Daily time-restricted feeding

• Fast every other day; no calorie restriction on non-fasting days

• 500 kcal/d on fasting days; no calorie

restriction on non-fasting days

• For 5 d/wk, eat normally without calorie restriction

• For 2 d/wk, eat 500–600 kcal/d

• 12–18 h of fasting per day; 6–12 h of feeding per day


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11.6%) in this patient population (34,35). For laparoscopic adjustablegastric band, retroflexion to evaluate for band erosion should beperformed.

Other evaluation

After the initial evaluation, additional studies, such as direct/indirectcalorimetry, Homeostatic Model Assessment of Insulin Resistance,liver ultrasound with elastography, and magnetic resonance elas-tography, may be obtained on a case-by-case basis. Furthermore,referral to appropriate specialists for signs or symptoms of non-GIobesity-related comorbidities should be considered.

OBESITY MANAGEMENTThe spectrum of obesity treatment options includes lifestylemodification, pharmacotherapy, endoscopy, and surgery.

Lifestyle modification

Lifestyle modification (LM) is considered first-line therapy for thetreatment of obesity. It includes 3 primary components—diet, exercise,and behavioral therapy.

To achieve weight loss, an energy deficit is required. This can beaccomplishedbyrestrictingcaloric intakeor limitingcertain food types.To reduce caloric intake, women should target 1,200–1,500 kcal/d,

whereas men target 1,500–1,800 kcal/d (8). Alternatively, an indi-vidual’s energy requirement may be estimated using calorimetry oravailable equations, and an energy deficit of 500–750 kcal/d or a 30%energy deficit can be prescribed. Alternatively, instead of a formalenergy deficit target, lower calorie intake may be achieved by re-striction or elimination of particular food groups, such as carbohy-drates. According to the US Dietary Guidelines, the recommendedmacronutrient proportions consist of carbohydrate (45%–65%),protein (10%–35%), and fat (20%–35%) (36). Adjusting these pro-portions may facilitate weight loss in some individuals by simplifyingdietary goals. Although there are no universally accepted definitions,examples of macronutrient-focused diet plans include high protein($20%–30% protein), low carbohydrate (,20% carbohydrate), andlow fat (,15%–20% fat) diets (37–40). There are several randomized,controlled trials comparing diets with various macronutrient com-positions. The largest study conducted by Sacks et al. randomized 811overweight adults to 1 of 4 diets—low fat/average protein (highestcarbohydrate: 65% of calories), low fat/high protein, high fat/averageprotein, and high fat/high protein (lowest carbohydrate: 35% of cal-ories). No significant differences in weight loss were observed amongthe 4 groups at 2 years (41). Other trials also demonstrated similarresults with meta-analyses showing that adherence is the strongestpredictor for weight loss (42). Macronutrient content may affect

Table 4. (continued)

Dietary plans Description

Commercial weight loss programs

HMR

Healthy solutions plan

Decision-free plan

• Meal replacement 1 home delivered meals (low calorie diet)

• 1,200 kcal/d

• 3-2-5 daily plan (3 HMR shakes, 2 HMR entrees, 5 servings of fruits,

vegetables)

• 500–800 kcal/d

• All shakes or 3-2 daily plan (3 HMR shakes, 2 HMR entrees)

• Medically supervised

Jenny Craig • Home delivered meals (low calorie diets)

• Individual in-person or telephone-based counseling sessions

Nutrisystem • Home delivered meals (low calorie/low glycemic index diets)

• 50% of total energy intake from carbohydrate

• 25% of total energy intake from protein

• 25% of total energy intake from fat

SlimFast diet • Meal replacement 1 home delivered meals (low calorie diet)

• 2 SlimFast meal replacements (shakes, bars, cookies)

• One 500–600 kcal meal of one’s choice

• Three 100 kcal snacks

South beach diet • Home delivered meals (modified low carbohydrate diets)

• ,50 g of carbohydrate per day (weight loss phase), then 75–100g of

carbohydrate per day (maintenance phase)

• Higher protein (25%–30% of total energy intake from protein)

• Healthy fat

Weight watchers • Points-based dietary system

•Member is assigned daily andweekly points based on height, weight, age,

gender

• Food is assigned points based on calories, saturated fat, sugar (increasedpoints), and protein (decreased points)

• Zero-point foods: fruits, nonstarchy vegetables, eggs, skinless chicken,fish, beans, tofu, and plain yogurt

• In-person meetings, web-based monitoring, or personal coaching calls


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Table 5. Commonly prescribed obesity medications

Medications Dosage/titration Mechanisms of action Efficacy Contraindications Common side effects FDA status

Phentermine (Adipex) 15 mg qd (starting dose)

37.5 mg qd

Norepinephrine-releasing

agent

6.8% TWL at 28 wk (96) Pregnancy/breastfeeding

History of CVD

MAOIs (within 14 d)

Hyperthyroidism

Glaucoma

History of drug abuse

Headache, elevated BP,

elevated HR, palpitations,

insomnia, dry mouth,

constipation, anxiety

Approved in 1960s for short-

term use (3 mo)

Orlistat (Xenical)

Alli (OTC)

120 mg tid before meals

60 mg tid before meals (for

Alli)

Pancreatic and gastric lipase

inhibitor

7.4% TWL at 1 yr (97) Pregnancy

Chronic malabsorption

syndrome

Cholestasis

Decreased absorption of fat-

soluble vitamins,

steatorrhea, oily spotting,

flatulence

Approved in 1999 for chronic

weight management

Phentermine (P)/

Topiramate ER (T) (Qsymia)

Alternative:

Phentermine (gen) 1

topiramate (gen)

P: 3.75 mg, T: 23 mg qd

(starting dose 3 14 d)

P: 7.5 mg, T: 46 mg qd

(recommended dose)

P: 15 mg, T: 92 mg qd (high

dose)

P: 15 mg qd1

T: 25 mg bid

Norepinephrine-releasing

agent (P)

1 GABA receptor

modulation (T)


MAOIs (within 14 d)

Hyperthyroidism

Glaucoma

Insomnia, dry mouth,

constipation, paresthesia,

dizziness


weight management

Naltrexone SR (N)/

Bupropion SR (B)

(Contrave)

N: 8 mg, B: 90 mg

2 tabs bid

Week 1: 1 tab qam

Week 2: 1 tab bid

Week 3: 2 tabs qam/1 tab

qpm

Week 4: 2 tabs bid

Opioid antagonist (N) 1

reuptake inhibitor of

dopamine and

norepinephrine (B)


Uncontrolled HTN

Seizure disorder

Bulimia or anorexia

Chronic opioid or opioid

agonist use

Alcohol withdrawal

MAOIs (within 14 d)

Headache, nausea,

constipation, dizziness


weight management

Liraglutide (Saxenda) 3 mg injectable qd

Week 1: 0.6 mg daily; then

increased by 0.6 mg weekly

until 3 mg daily is reached

GLP-1 agonist 8.0% TWL at 1 yr (100) Pregnancy

Personal or family history of

medullary thyroid

Carcinoma or multiple

Endocrine neoplasia

Syndrome type 2

Nausea, vomiting,

pancreatitis


weight management

Metformin (Glucophage) 500 mg qd (starting dose)

1,000 mg bid (max dose)

Decreases hepatic glucose

production

Decreases intestinal glucose

absorption

Increases peripheral glucose

uptake

2.3 kg additional weight loss

compared to placebo (101)

Chronic heart failure

Metabolic acidosis

Diabetic ketoacidosis

Severe renal disease

Nausea, vomiting, diarrhea,

flatulence

Off-label for obesity

Approved for T2DM

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patient preferences but is only one of many factors influencing ad-herence. Given the relatively equivalent efficacy of different dietaryapproaches, a diet planmay be chosen based onmetabolic risk factorsand patient preferences. Specifically, low fat diets induce greater re-duction in low-density lipoprotein,whereas lowcarbohydratediets areassociated with greater improvement in triglycerides, high-density li-poprotein, and HbA1c (41,43–46). Table 4 summarizes the morecommonly prescribed diet plans.

Physical activity is an essential component of a weight loss pro-gram. Specifically, at least 150minutes of aerobic activity per week isrecommended (at least 30 minutes per day, most days of the week)(8,47), with at least 2 resistance training days per week (minimumof1 set of 8–12 repetitions for a total of 8–10 exercises per week) (48).Resistance training is important because it helps improve musclestrength and endurance, modify coronary risk factors, and preservefat-free mass during weight loss to enhance metabolic rate (49,50).During the weight maintenance phase, higher levels of physical ac-tivity of 200–300 minutes per week are recommended (51).

Behavioral therapy targets maladaptive eating behaviors, ac-tivity, and thinking habits that contribute to obesity. It includesseveral components. Self-monitoring is perhaps the most im-portant component of behavioral therapy. Patients are advised torecord the type, amount, and total calories of their food con-sumption, and physical activity and body weight. Studies showthat individuals that routinely record their food intake lose moreweight than those who do not (52). Other components of be-havioral therapy include (i) stimulus control (such as storing foodout of sight, limiting eating places to the kitchen and dining table,and refraining from eating while engaging in other activities), (ii)problem solving (such as planning meals ahead of time whiletraveling), (iii) cognitive restructuring (such as recognizing asetback as a temporary lapse and continuing to move forwardinstead of giving up), and (iv) relapse prevention focusing onhigh-risk situations (such as vacations, illness, or periods of highstress). Traditionally, behavioral therapy is offered in group ses-sions of 10–20 individuals by registered dietitians, psychologists,exercise specialists, or other health professionals, with each ses-sion lasting 60–90 minutes. It is often held weekly during theactive weight-loss phase (6 months) and may taper to biweeklyduring the weight-maintenance phase (53).

In clinical practice, LM is usually prescribed comprehensivelyto modify both eating and activity habits. To date, there are 2landmark studies evaluating the efficacy of LM: the DiabetesPrevention Program and Look AHEAD studies (54). The Di-abetes Prevention Program study compared LM (16 sessionsduring the first 6 months, followed by monthly contacts) withmetformin with placebo at delaying or preventing developmentof type 2 diabetes (T2DM) in 3,200 patients with impaired glucosetolerance. At 1 year, LM patients lost 7 kg compared with 0.1 kgfor placebo. The risk of developing T2DMwas reduced by 58% inthe LM group compared with placebo and 31% compared withmetformin. At 10 years, participants regained almost all of theirlost weight (with no differences in weight loss among groups).Nevertheless, the incidence of T2DM remained the lowest in theLMgroup (55). In comparison, the LookAHEADstudy evaluatedthe effect of intensive lifestyle intervention (ILI) (24 sessionsduring the first 6 months, followed by 18 sessions in months7–12) vs usual care (diabetes support and education) in 5,100overweight participants with T2DM. At 1 and 4 years, patients inthe ILI and diabetes support and education experienced 8.6% vs0.7% TWL and 4.7% vs 1.1% TWL, respectively. The ILI groupT

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Figure 1. Primary bariatric endoscopic interventions. BMI, body mass index; GI, gastrointestinal; ITT, Intention-to-treat; TWL, total weight loss.


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Obesity Primer 927


also experienced significantly greater improvement in HbA1cand several measures of cardiovascular diseases (56,57).

Overall, a comprehensive LM program should be in-corporated as part of every weight loss intervention. LM alonemay result in weight loss ranging from 1.4% to 8.6% TWLdepending on the intensity (56,58,59). Key components to successinclude a diet plan that patients can adhere to, incorporation ofphysical activity, and a behavioral treatment plan to reinforce thenecessary strategies to maintain the lost weight.

Pharmacotherapy

Weight-loss medications may be considered when patients failto respond to lifestyle modification and have a BMI of $30 or$27 kg/m2 with obesity-related comorbidities (8,60). Beforeinitiation of a weight-loss medication, current medicationsshould be reviewed to identify any that are associated withweight gain and should be substituted withmore weight-neutralmedications (Table 2). To date, there are 5 antiobesity medi-cations approved by the Food and Drug Administration

Figure 2. Bariatric surgeries. Outcome data from meta-analyses or largest available series. DI, duodeno-ileal; EWL, excess weight loss; GEJ, gastro-esophageal junction; GJA, gastrojejunal; ICV, ileocecal valve; II, ileoileal; JJA, jejunojejunal; PE, pulmonary embolism; SBO, small bowel obstruction; TWL,total weight loss.


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Table 6. Complications of common bariatric surgeries

Complications

Time of onset since

surgery Diagnostic modalities Management strategies

Sleeve gastrectomy

Sleeve leaks Post-operative or early Cross-sectional imaging Depends on time from surgery

Esophageal stent for acute leaks

Pigtail stents for chronic leaks

Sleeve stenosis Anytime Distinguish between stenosis and twisting;

consider imaging

Hydrostatic or pneumatic balloon dilation of sleeve

depending on time from surgery and degree of stenosis

Twisted sleeve less likely to respond

Reflux and its

complications

Late Upper endoscopy High dose PPI 1/2 sucralfate for acid reflux

Cholestyramine for bile reflux

Surgical conversion to RYGB

Roux-en-Y gastric bypass

Surgical leaks Post-operative or early Cross-sectional imaging

High false negative rates for all studies

Depends on location of leak and time from surgery

Esophageal stents for acute pouch and GJ leaks

Clips for JJ leaks

Pigtail drainage for chronic walled-off leaks

GJA ulceration Early or late Do not advance endoscope deeply beyond

area of ulceration

Helicobacter pylori stool antigen or

serology

High dose PPI (soluble form) 1/2 sucralfate

Treat H. pylori if positive

Stop smoking and optimize glycemic control

Stop NSAIDs

Consider suture removal

GJA stenosis Late Upper endoscopy

Avoid UGI series given aspiration risk

Look for concomitant ulceration

Stepwise endoscopic balloon dilation

Do not overdilate (#15 mm)

Carefully direct wire into Roux limb

Foreign body removal

Consider LAMS for selected cases

Gastrogastric fistula Early or late Upper GI series sensitive

Upper endoscopy important to confirm

and rule out ulceration

If asymptomatic, PPI 1 dietary counseling

If symptomatic, closure (endoscopic [,1 cm] vs surgical)

Intestinal obstruction Early or late Cross-sectional imaging while

symptomatic to look for intussusception

and internal herniation

Surgery

Endoscopy is not indicated for extraluminal causes of

obstruction

Choledocholithiasis Late RUQ ultrasound

Cross-sectional imaging

MRCP

Device-assisted enteroscopy

Laparoscopic-assisted ERCP

EUS-directed ERCP

IR-guided percutaneous drainage

Dilated GJA Late Upper endoscopy

Dilation confirmed with GJA .15 mm

Endoscopic revision (TORe)

APC for incompetent yet not

markedly dilated GJA

Laparoscopic adjustable gastric band

Reflux esophagitis Late Upper endoscopy High dose PPI 1/2 sucralfate

Band deflation

Esophageal dilatation Late Upper endoscopy

Upper GI series

Band deflation

Surgical replacement or conversion

Band erosion Late Upper endoscopy Endoscopic removal of band if buckle is visible with

surgical removal of port

Band slippage Late Upper GI series Surgery

APC, argon plasmacoagulation; ERCP, endoscopic retrograde cholangiopancreatography; EUS, endoscopic ultrasound;GJ, gastrojejunal; GJA, gastrojejunal anastomosis;IR, interventional radiology; JJ, jejunojejunal; LAMS, lumen-apposing metal stent; MRCP, magnetic resonance cholangiopancreatography; PPI, proton pump inhibitor;RUQ, right upper quadrant; TORe, transoral outlet reduction.


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Obesity Primer 929


(FDA)—phentermine, orlistat (Xenical), phentermine/topiramate (Qsymia), naltrexone/bupropion (Contrave), andliraglutide (Saxenda) (Table 5). With the exception of orlistat,which blocks absorption of 25%–30% of fat calories, thesemedications target appetite mechanisms specifically by workingin the arcuate nucleus to stimulate pro-opiomelanocortin neu-rons to promote satiety. It is important to discuss both potentialbenefits and adverse events of each medication before its initi-ation and to document the conversation, especially when themedication is used off-label. Furthermore, pregnancy is con-traindicated for all weight-lossmedications, and patients shouldbe advised to use dual contraceptive methods.

Although there is no generalizable hierarchical algorithm formedication selection, specificmedications are preferred in certainclinical settings based on efficacy, adverse events, warnings,contraindications, organ clearance, and mechanisms of action(61). For example, phentermine/topiramate should be consideredin patients with migraine, bupropion/naltrexone for those withsmoking or depression history, and liraglutide for those withdiabetes/prediabetes. In addition, certain medications should beavoided in patients with specific comorbidities. For example,patients with uncontrolled hypertension or a history of heartdisease should not be prescribed phentermine. Patients with anelevated seizure risk should avoid bupropion/naltrexone.

An effective response is defined as $5% TWL at 3 monthsafter the initiation of a weight-loss medication. If the response isdeemed ineffective (,5% TWL at 3 months) or if safety or in-tolerability issue arises, the medication should be discontinuedand switched to an alternative medication or treatment ap-proach (26).

Gelesis100 is a procedureless intervention that was FDA-approved based on pharmacotherapy thresholds and represents anew class of obesity treatments. It is a hydrogel capsule that isorally administered with water before a meal. When hydrated,Gelesis100 occupies about one-fourth of the gastric volume. Theparticles maintain their gel form while passing through the smallintestine before breaking down in the colon. A pivotal trial(GLOW trial) randomized 436 patients to Gelesis100 vs placebo.At 6 months, the Gelesis100 group experienced 6.4% TWL (vs4.4%TWL for placebo), with 59% achieving$5%TWL (62). Thistechnology is not yet commercially available.

In addition to the medications listed above, there are severalantiobesity agents under development and currently undergoingclinical trial. For a newdrug to be approved forweight loss, itmustmeet the FDA thresholds, defined as significant placebo-adjustedweight loss of$5% TWL at 1 year or$35% of patients achieving$5%TWL (whichmust be at least twice that induced by placebo).

Bariatric Endoscopy

Bariatric endoscopy may be divided into gastric and small bowelinterventions (63,64). In general, gastric interventions primarilyinduce weight loss with secondary effects on metabolic condi-tions. By contrast, small bowel interventions have direct effects onmetabolic conditions with or without weight loss. To date, thereare 3 types of bariatric endoscopic devices that are FDA-approvedand available (Figure 1).

Intragastric balloons occupy space in the stomach and seem toalter gastric motility (65). There currently are 2 IGBs available intheUnited States—Orbera (Apollo Endosurgery, Austin, TX) andObalon (Obalon Therapeutics, Carlsbad, CA). Orbera is a singlefluid-filled balloon that is placed and removed endoscopically at 6

months. Obalon is a 3-balloon system, filled with nitrogen gas,swallowed 4 weeks apart, with positioning confirmed via x-ray ormagnetic resonance. All balloons are removed endoscopically at 6months. An Orbera meta-analysis (17 studies/1,638 patients)demonstrated an 11.3% TWL at 12 months. The most commonAEs were pain and nausea (33.7%). The severe adverse event(SAE) rate was 1.6%, including migration (1.4%), perforation(0.1%), and death (0.08%) (66). For Obalon, a randomized sham-controlled trial revealed a 6.9% TWL at 12 months with an SAErate of 0.4% (67). However, the real-world experience (1,343patients) showed a 10%TWLwith an SAE rate of 0.15% includingsevere abdominal pain and gastric perforation (68).

Gastric remodeling may be performed via endoscopic sutur-ing or plication and dates back to as early as 2008 (69–71). Cur-rently, there are 2 devices that are cleared by the FDA for tissueapproximation and are used for this purpose, however, withoutspecific weight loss claims—Overstitch (Apollo Endosurgery)and Incisionless Operating Platform (USGI Medical, San Clem-ente, CA). Endoscopic sleeve gastroplasty is the most commongastric remodeling procedure that involves placing several su-tures in a running fashion along the greater curvature. A secondlayer of sutures may also be placed medially for reinforcement(72). A meta-analysis (8 studies/1772 patients) revealed its effi-cacy to be 16.5% TWL at 12 months and an SAE rate of 2.2%including pain/nausea, bleeding, perigastric leak, and fluid col-lection (73). At 5 years, a single center study (56 of 68 patientswho were eligible for the 5-year follow-up from the original co-hort of 216 patients) revealed a 15.9% TWL (compared with15.6% at 1 year) (74). In comparison, gastric plication, also knownas Primary Obesity Surgery Endoluminal (POSE), involvesplacement of tissue plications in the stomach. In contrast to en-doscopic sleeve gastroplasty which may be endoscopically re-versible, POSE focuses on serosal apposition and is not reversible.The traditional POSE procedure involves placement of plicationsprimarily in the fundus (75). A more recent pattern, also knownas distal POSE or POSE2, however, involves placement of plica-tions solely in the gastric body (76–78). A meta-analysis (5studies/586 patients) demonstrated that traditional POSE wasassociated with 12.1% and 13.2% TWL at 6 and 12–15 months,respectively, with an SAE rate of 3.2% including chest pain, low-grade fever, extragastric bleeding, and hepatic abscess (79). Withthe new plication pattern, the efficacy seemed to be higher withapproximately 15% and 17.5% TWL at 6 and 9 months, re-spectively (76–78,80). Preliminary results suggest that patientswith class III obesity may experience greater weight loss (19-20%TWL at 1 year) following ESG or distal POSE compared to thosewith class I and II (80,81).

Aspiration therapy removes a portion of food from thestomach after ingestion. The system consists of a large fenestratedgastrostomy tube (A-tube), an external port at the skin for aspi-ration, and a portable device to perform aspiration. The A-tube isplaced endoscopically via a standard pull technique, and the portis attached at 1–2 weeks. Ameta-analysis (5 studies/590 patients)demonstrated a 17.8% TWL at 1 year with an SAE rate of 4.1%including buried bumper, peritonitis, abdominal pain, andproduct malfunction (82).

In addition to weight loss efficacy, all of the approved gastricdevices and/or procedures discussed above have been shown toimprove obesity-related comorbidities, such as diabetes and fattyliver (82–86). The effect of endoscopic bariatric procedures onconception, however, remains unknown.


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Other gastric devices including the Spatz and Elipse balloonsystems are currently undergoing FDA review, whereas somesmall bowel interventions such as duodenal-jejunal bypass linerand duodenal mucosal resurfacing are undergoing US clinicaltrials. According to the ASGE/ASMBS, a new endoscopic pro-cedure intended as a primary obesity intervention should achieve$25% excess weight loss (EWL) at 1 year with aminimumof 15%EWL over control with an SAE rate ,5% (87).

Bariatric surgery

Bariatric surgery should be considered for patients with a BMI of$40 or $35 kg/m2 with at least 1 comorbidity (88). Althoughseveral bariatric surgical procedures are available (Figure 2), SGand RYGB remain the most commonly performed.

SG involves removal of the fundus and greater curvature tocreate a tubular structure along the lesser curvature. The smallbowel remains unaltered. A meta-analysis (11 studies/over 3,000patients) revealed that patients experienced 51.5% EWL at 1 year.The pooled mortality rate was 0.6% with an AE rate of 8.9% andreoperation rate of 3% (89). In a single center study, 51 of theoriginal cohort of 165 patients experienced 60.5% EWL at 5 years(compared with 82% EWL at 1 year) (90).

RYGB is the preferred surgery for patients with obesity andconcomitant metabolic diseases or gastroesophageal reflux dis-ease.DuringRYGB, the stomach is divided into a small pouch anda larger remnant stomach. The jejunum is transected, followed byconnecting one end to the pouch at the gastrojejunal anastomosisand the other end to the proximal jejunum at the jejunojejunalanastomosis. A meta-analysis (17 studies/over 8,000 patients)revealed that patients experienced 63.3% EWL at 1 year afterRYGB.The pooledmortality ratewas 1.1%with anAE rate of 12%and reoperation rate of 5.3% (89). At 12 years, the average weightloss is 27% TWL (n5 387) (91).

In addition to SG and RYGB, other procedures that are stillbeing performed at a smaller proportion include gastric bandingand biliopancreatic diversion with duodenal switch. Further-more, there are several emerging procedures, such as minigastricbypass and single anastomosis duodenoileal bypass with sleevegastrectomy, which gastroenterologists should become familiarwith (Figure 2).

ENDOSCOPIC MANAGEMENT OF BARIATRICSURGICAL COMPLICATIONSAs the number of bariatric surgeries continues to rise, gastroen-terologists will see more patients with surgically altered anatomy.In addition to understanding normal and abnormal endoscopicfindings in this patient population (see above), gastroenterolo-gists should be familiar with potential complications and theirmanagement. Table 6 summarizes complications after each of thecommon bariatric surgeries, presenting symptoms, and man-agement strategies (92). Furthermore, nutrient deficiencies maybe seen after all bariatric surgeries, such as vitamins B1/B12, D, A,folate, iron, and calcium, with the addition of zinc and copper forbiliopancreatic diversion with duodenal switch and RYGB(93,94). Therefore, adherence to vitamin supplements should beassessed with a low threshold to check these levels, especially forthose who are not routinely followed by bariatric surgery. Inaddition, weight regain after bariatric surgery is not uncommonand is likely caused by several etiologies including medical, be-havioral, hormonal, pharmacologic, and anatomical factors.

Gastroenterologists should routinely ask for prebariatric surgical,nadir, and current weights. If weight regain is encountered, re-ferral to a multidisciplinary team, including dietitian, obesitymedicine expert, bariatric endoscopist, and bariatric surgeon, forconsideration of pharmacotherapy and/or endoscopic revision ofbariatric surgery is recommended. There are several effectiveendoscopic treatment options for weight regain; however, this isbeyond the scope of this article.

DEVELOPING EXPERTISE IN OBESITY MEDICINE ANDBARIATRIC ENDOSCOPYThere are several resources available for gastroenterologists whoplan on specializing inObesityMedicine andBariatric Endoscopy(95). These programs focus on cognitive elements, skill set de-velopment, and center requirements. American Board of ObesityMedicine credentialing is also available for board-certified gas-troenterologists without the need for additional training.

From a center standpoint, there are also several infrastructureand personnel considerations. These include having a patient-friendly waiting area (such as wide chairs and reinforced toilets)and medical equipment (such as extra-large blood pressure cuffsand bariatric scales). Staff training to reduce bias and stigma andto encourage the use of people-first language and terms such asunhealthy weight rather obese is also encouraged. Furthermore, amultidisciplinary team, which includes bariatric surgeons, bari-atric endoscopists, obesity medicine experts, dietitians, psychol-ogists, health coaches, and/or social workers, is essential and canbe assembled with the help of modern virtual platforms. In ad-dition, these platforms may be used as part of the aftercare pro-gram. Moreover, fitness applications and calorie tracking devicesmay be useful to encourage adherence to LM.

CONCLUSIONGastroenterologists will continue to see an increasing number ofpatients with obesity. These patients are at greater risk of GIcomorbidities and require special consideration. Similarly, bari-atric surgery carries various complications that necessitate uniquemanagement strategies. Finally, gastroenterologists are well po-sitioned to manage obesity medically and endoscopically andshould adopt a greater role in addressing this pandemic.

CONFLICTS OF INTEREST

Guarantor of the article: Christopher C. Thompson, MD, MSc.Specific author contributions: P.J.: wrote the manuscript. C.C.T.:critically reviewed the article for important intellectual content. Allauthors approved the final draft of the article.Financial support: NIH T32 DK007533 and P30 DK034854.Potential competing interests: P.J. has received research supportfrom Apollo Endosurgery - Research Support, Boston Scientific -Research Support, Endogastric Solutions - Consultant, Fractyl -Research Support, GI Dynamics - Consultant (Consulting fees),Research Support, Lumendi - Consultant. C.C. Thompson: ApolloEndosurgery - Consultant/Research Support (Consulting fees/Institutional Research Grants), Aspire Bariatrics - Research Support(Institutional Research Grant), BlueFlame Healthcare Venture Fund- General Partner, Boston Scientific - Consultant (Consulting fees)/Research Support (Institutional Research Grant), Covidien/Medtronic - Consultant (Consulting fees), EnVision Endoscopy -Board Member, ERBE - Institutional Research Grant, Fractyl -Consultant/Advisory Board Members (Consulting fees), FujiFilm -Institutional Research Grant, GI Dynamics - Consultant (Consulting


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Obesity Primer 931


fees)/Resaerch Support (Institutional Research Grant), GI Windows- Ownership Interest, Lumendi - Consultant/Institutional ResearchGrant, Olympus/Spiration - Consultant (Consulting fees)/ResearchSupport (Equipment Loans), USGI Medical - Consultant(Consulting fees)/Advisory Board Member (Consulting fees)/Research Support (Institutional Research Grant)

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