From Clinic to Recovery · First Edition
Chapter 13 — Obesity and Metabolic and Bariatric Surgery: Choosing Treatment and Living Well Afterward
Dr. Tamer Rushdy Elalfy · 21 min read
In this chapter
- 13.1 Talking about weight respectfully
- 13.2 The range of treatments
- 13.3 Who is suitable for surgery
- 13.4 Choosing the operation
- 13.5 Before the operation
- 13.6 Eating after surgery
- 13.7 Lifelong supplements and follow-up
- 13.8 Ramadan, pregnancy, and daily life
- 13.9 Material risks
- 13.10 Consent checklist
- 13.11 Warning signs
- References
Obesity is a chronic, relapsing disease, not a failure of willpower. Most people who come to a bariatric clinic have tried many diets, often for years, and many have already used weight-loss injections. They arrive with hope, with fear of surgery, and often with advice from friends who had operations, sometimes abroad. The surgeon’s role is to help each patient understand all the options, from lifestyle change and medicines to endoscopic procedures and surgery, to choose the one that suits their health and life, and to prepare them for the lifelong changes that follow. Good education before surgery, and good follow-up afterward, prevent many of the complications described in this chapter.
Learning objectives After reading this chapter you should be able to:
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Table 13.1. Obesity treatment and bariatric surgery at a glance.
| At a glance | |
|---|---|
| Treatments | Lifestyle program; weight-loss medicines; endoscopic sleeve or balloon; sleeve gastrectomy; gastric bypass; other bypass procedures |
| Surgery is considered for | Body mass index (BMI) of 35 or more, or 30 to 34.9 with metabolic disease such as type 2 diabetes |
| Hospital stay | Usually 1 to 2 nights |
| Back to office work | About 2 to 3 weeks |
| Risks every patient should hear | Leak, bleeding, clots, reflux after sleeve, ulcer and internal hernia after bypass, vitamin deficiency, weight regain, and changes in mood |
| The key counseling message | “Surgery is a powerful tool, not a cure on its own. It works best with lifelong healthy eating, vitamins, and follow-up.” |
STEP 1 Explaining obesity and the choices
13.1 Talking about weight respectfully
Many patients have experienced judgment from health professionals, and this makes them less likely to seek help. Ask permission before discussing weight, use person-first language (“a person with obesity”), and avoid words such as “fat” or “morbidly obese.” Weigh patients in private, with equipment that fits. Explain obesity as a disease of appetite and metabolism that the body defends: when weight falls, hunger rises and energy use falls, which is why diets alone so often fail. Patients are relieved to hear that their struggle has a biological explanation.
Script: opening the conversation “Would it be all right if we talked about your weight today?” “Tell me what you have tried so far, and what has made it hard.” “Obesity is a medical condition. Your body works hard to hold on to weight, which is why diets alone so often do not last. That is not your fault. There are now several effective treatments, and I would like to help you choose the one that fits you best.” |
13.2 The range of treatments
Every patient should understand the full range of options and what each can realistically achieve (Figure 13.1). A structured lifestyle program typically achieves about 9 in 100 of body weight at one year [1], and remains the foundation of every other treatment. Among medicines, weekly tirzepatide led to an average loss of about 20 in 100 of body weight at 72 weeks, and semaglutide about 14 in 100, in a head-to-head trial [2]. These medicines work while they are taken; after semaglutide was stopped, about two-thirds of the lost weight returned within a year [3]. Endoscopic sleeve gastroplasty, performed through the mouth, achieved about 14 in 100 at one year [4]. Surgery produces the largest and most durable loss: in a large cohort, average loss at 5 years was about 19 in 100 after sleeve gastrectomy and about 26 in 100 after gastric bypass [5].
[Figure — diagram omitted in this text edition; see the figure caption below and the Word chapter file for the image]
Figure 13.1. Average weight loss with different obesity treatments, for use with patients.
Caution: weight-loss injections and surgery Ask every patient about current or previous weight-loss injections, including products bought online or abroad. Record the drug, dose, and date of the last dose, and follow the anesthesia guidance in Chapter 2 and Chapter 23 before any operation. These medicines can also be used after surgery when weight is regained, as part of a team plan. |
13.3 Who is suitable for surgery
Current international criteria recommend metabolic and bariatric surgery for adults with a BMI of 35 or more, regardless of other conditions, and suggest considering it for those with a BMI of 30 to 34.9 who have metabolic disease, such as type 2 diabetes [6]. Lower thresholds apply to people of Asian descent, in whom metabolic disease occurs at a lower BMI [6]. Surgery is also an option for selected adolescents with severe obesity (Chapter 25).
Suitability depends on more than BMI. A multidisciplinary assessment, usually including a surgeon, dietitian, psychologist or psychiatrist, and physician, checks that the patient understands the lifelong changes, has stable mental health, has stopped smoking, and has a plan for contraception. Untreated eating disorders, active substance misuse, and inability to follow lifelong supplements and follow-up are reasons to delay surgery and offer support first.
Script: setting realistic expectations “Most people lose a large amount of weight in the first year or two after surgery, and keep most of it off. Some weight usually comes back after a few years, and this is normal. The operation reduces hunger and helps you feel full on small meals, but your choices about food, activity, and vitamins still matter, for the rest of your life.” |
13.4 Choosing the operation
Sleeve gastrectomy and Roux-en-Y gastric bypass are the two most common operations, and both give good, lasting results. In a randomized trial followed for 10 years, the loss of excess weight was 44 in 100 after sleeve and 51 in 100 after bypass, and reflux inflammation of the esophagus was seen in 31 in 100 after sleeve compared with 7 in 100 after bypass; Barrett esophagus was uncommon and similar after both, at about 4 in 100 [7]. In patients with type 2 diabetes, surgery achieved near-normal blood sugar without diabetes medicines far more often than intensive medical therapy at 5 years [8]. Figure 13.2 lists factors that may favor each operation; Table 13.2 compares the main procedures.
[Figure — diagram omitted in this text edition; see the figure caption below and the Word chapter file for the image]
Figure 13.2. Factors that may favor sleeve gastrectomy or gastric bypass, for shared decision-making.
Table 13.2. Main procedures for obesity compared.
| Operation | How it works | Main advantages | Main disadvantages |
|---|---|---|---|
| Sleeve gastrectomy | About three-quarters of the stomach is removed, leaving a narrow tube | Simpler; no rerouting; fewer nutritional problems | New or worse reflux; cannot be reversed |
| Roux-en-Y gastric bypass | A small stomach pouch is joined to the small bowel, bypassing most of the stomach | More weight loss; treats reflux; strong effect on diabetes | Ulcers at the join; internal hernia; dumping; more supplements; avoid anti-inflammatory medicines |
| One-anastomosis gastric bypass | A longer pouch joined to the small bowel with a single join | Simpler than Roux-en-Y bypass; good weight loss | Bile reflux; risk of malnutrition if the bypassed bowel is long |
| Duodenal switch and its variants | Sleeve combined with a long bowel bypass | Greatest weight loss; for selected patients with very high BMI | Highest risk of malnutrition and diarrhea; more demanding follow-up |
| Endoscopic sleeve gastroplasty | The stomach is stitched smaller from inside, through the mouth | No incisions; day case; reversible | Less weight loss than surgery; long-term data limited |
STEP 2 Preparation, medicines, and lifelong follow-up
13.5 Before the operation
- Assessment. Blood tests, including vitamins and iron; endoscopy where the unit’s protocol or reflux symptoms require it; review by the dietitian and psychologist.
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Liver-shrinking diet. Many units ask patients to follow a low-calorie diet for about two weeks before surgery to make the operation safer.
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Smoking. Stop completely. Smoking increases ulcers after bypass and other complications.
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Contraception. Women should avoid pregnancy until weight has stabilized, usually 12 to 18 months after surgery [9]. After bypass, absorption of oral contraceptive pills may be unreliable, so other methods are often advised.
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Medicines. Weight-loss injections, diabetes medicines, and blood thinners need individual plans (Chapters 18, 22, and 23).
13.6 Eating after surgery
After surgery, food is reintroduced in stages over about six weeks (Figure 13.3). The rules are simple, and patients should hear them several times: eat protein first, aiming for at least 60 g a day; take small bites and chew well; stop at the first sign of fullness; sip water between meals rather than with them; and avoid sugary drinks and grazing [9]. Hair thinning in the first months is common and usually recovers.
[Figure — diagram omitted in this text edition; see the figure caption below and the Word chapter file for the image]
Figure 13.3. The four stages of eating after weight-loss surgery, for use with patients.
13.7 Lifelong supplements and follow-up
All patients need lifelong supplements, usually a complete multivitamin with minerals, calcium with vitamin D, vitamin B12, and iron where needed, with higher needs after bypass, and regular blood tests to detect deficiency [9]. Explain why this matters: deficiencies develop silently and can cause anemia, bone thinning, and nerve damage. Persistent vomiting can cause severe thiamine (vitamin B1) deficiency within weeks, which is an emergency. Follow-up with the bariatric team is lifelong, and patients who had surgery elsewhere, including abroad, should be welcomed into local follow-up.
13.8 Ramadan, pregnancy, and daily life
Fasting during the first months after surgery risks dehydration and inadequate protein. Most teams advise against fasting during the first 6 to 12 months; after that, many patients can fast with a plan for protein and fluids between iftar and suhoor and supplements taken at night, agreed with the dietitian. Pregnancy after surgery is usually safe once weight has stabilized, but needs early notification of the team, nutritional monitoring, and an alternative to the standard glucose tolerance test, which can cause dumping after bypass.
Table 13.3. Typical recovery and milestones after bariatric surgery.
| Activity | Usually from | Notes |
|---|---|---|
| Walking | The same day | Walk several times a day to prevent clots |
| Showering | Day 1 or 2 | Pat the small wounds dry |
| Driving | About 1 to 2 weeks | When you can brake firmly and are not taking strong pain medicine |
| Office work | About 2 to 3 weeks | Take water and protein snacks to work |
| Exercise | Light from the first week; full by 4 to 6 weeks | Build up to regular activity; strength exercise protects muscle |
| Prayer | From the first day | Bowing and prostration as comfort allows |
| Ramadan fasting | Usually not in the first 6 to 12 months | Agree a plan with the dietitian before fasting |
| Pregnancy | Usually after 12 to 18 months | Tell the team as soon as you are pregnant |
STEP 3 Questions patients ask
“Isn’t surgery the easy way out?”
No. Obesity is a medical condition, and surgery is a medical treatment for it, like any other. It takes real commitment before and after, for life.
“Why not just take the injections?”
They are a good option for many people, and work well while you take them. Most people need them long-term, because weight usually returns when they stop [3]. Surgery gives more lasting weight loss for most people with severe obesity [5].
“Will I regain weight?”
Some regain after the first few years is common and normal. Large regain is less common, and can be treated with diet support, medicines, or sometimes further surgery.
“Sleeve or bypass: which is better for me?”
Both work well. If you have bad heartburn or long-standing diabetes, a bypass is often better. If you take anti-inflammatory medicines regularly or want a simpler operation with fewer vitamin problems, a sleeve may suit you better. We will decide together (Figure 13.2).
“Will my diabetes go away?”
Many people come off some or all of their diabetes medicines. Surgery achieved near-normal blood sugar without medicines far more often than medical treatment alone [8]. Diabetes can return in later years, so checks continue.
“Is the operation safe?”
It is one of the safer major operations. The risk of dying is about 5 in 10,000 after a sleeve and about 9 in 10,000 after a bypass [10], and the health benefits of weight loss are large.
“Will I need vitamins forever?”
Yes. Your body absorbs less from food after surgery. Without supplements, deficiencies develop slowly and can cause serious problems [9].
“Can I get pregnant afterward?”
Yes, and fertility often improves. Wait 12 to 18 months until your weight is stable, use reliable contraception until then, and tell us as soon as you are pregnant [9].
“Will I have loose skin?”
Often, after large weight loss. Some people choose body-contouring surgery once weight has been stable for some time.
“Can I have the operation abroad?”
Many people do, but the operation is only the beginning. Make sure you have lifelong follow-up and blood tests arranged, and bring your operation records to us.
“Can I fast in Ramadan?”
Usually not in the first 6 to 12 months. After that, many people can fast with a plan for protein, fluids, and vitamins, agreed with the dietitian.
“Will my mood change?”
Many people feel better, but some find the changes difficult. A small increase in alcohol problems and in self-harm has been reported after surgery [11]. We will ask about your mood at every visit, and you can always talk to us.
STEP 4 Risks, warning signs, and consent
13.9 Material risks
Table 13.4 groups the risks into the bands of Section 1.5. Replace figures marked “unit data” with your own audit figures.
Table 13.4. Material risks of sleeve gastrectomy and gastric bypass. Square brackets mark figures to replace with unit data.
| Band | Risk | Typical frequency | Example wording |
|---|---|---|---|
| Common | Reflux and esophagitis after sleeve | Esophagitis in about 31 in 100 at 10 years, against 7 in 100 after bypass [7] | “Heartburn is more common after a sleeve. It is usually treated with medicine; some people need a bypass later.” |
| Common | Nutritional deficiency without supplements | Common, especially after bypass [9] | “Without vitamins, most people become deficient over time.” |
| Common | Temporary hair thinning; loose skin | Many patients | “Hair often thins for a few months and then recovers.” |
| Less common | Leak from a staple line or join | [unit data] | “Rarely, a leak happens. It may need a drain, a stent, or another operation.” |
| Less common | Ulcer at the join after bypass; narrowing; gallstones | [unit data] | “Ulcers are more likely if you smoke or take anti-inflammatory medicines.” |
| Less common | Internal hernia after bypass, months or years later | [unit data] | “Bowel can twist through a gap inside. Severe tummy pain needs urgent review.” |
| Less common | Dumping and low blood sugar after meals (after bypass) | [unit data] | “Sweet foods can make you feel faint and sweaty.” |
| Rare but serious | Bleeding; blood clots in legs or lungs | [unit data] | “We give injections and get you walking to prevent clots.” |
| Rare but serious | Alcohol misuse, self-harm, or suicide | A small increase reported after surgery [11] | “We will ask about your mood and drinking at every visit.” |
| Rare but serious | Death | About 5 in 10,000 after sleeve; 9 in 10,000 after bypass [10] | “The risk of dying is less than 1 in 1,000.” |
13.10 Consent checklist
Before the patient signs ☐ All treatment options discussed, including lifestyle, medicines, endoscopic procedures, and surgery, with expected weight loss. ☐ Eligibility confirmed and multidisciplinary assessment complete, including mental health. ☐ Choice of operation shared, considering reflux, diabetes, medicines, and patient priorities. ☐ Early and late risks from Table 13.4 discussed, including reflux, deficiency, internal hernia, and mood. ☐ Lifelong supplements, blood tests, and follow-up agreed. ☐ Smoking stopped; contraception and pregnancy timing discussed. ☐ Weight-loss injections and other medicines recorded and managed. ☐ Who will perform the operation, including trainee involvement under supervision. ☐ Teach-back done, and the patient guide given in the patient’s language. |
13.11 Warning signs
After bariatric surgery, the usual signs of a leak or internal hernia can be subtle. A fast heart rate may be the only early sign of a leak, and a patient who cannot keep fluids down needs urgent review because of the risk of dehydration and thiamine deficiency.
Table 13.5. Green, amber, and red warning signs after bariatric surgery.
| Level | Signs after bariatric surgery | What to do |
|---|---|---|
| Green | Mild wound and shoulder pain that improves Feeling full quickly; small meals Tiredness and hair thinning in the first months | Expected. Follow the guide and the eating stages. |
| Amber | Vomiting after most meals, or food sticking Heartburn that is not controlled Feeling faint or sweaty after eating Low mood, or drinking alcohol more than before | Call the bariatric team the same day or at the next working day. |
| Red | Fast heartbeat, fever, or increasing tummy or left shoulder pain, especially in the first two weeks Unable to keep any fluids down for 12 hours Severe or colicky tummy pain at any time after a bypass Black stools or vomiting blood Confusion, unsteadiness, or double vision with vomiting Chest pain, breathlessness, or a hot, swollen calf | Go to the emergency department now. Say that you have had weight-loss surgery. |
Key points
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STEP 5 Patient education guide
The following pages may be photocopied and given to patients. Tick the operation the patient had, and add your unit’s name, the bariatric team’s phone number, and the review date before use.
PATIENT GUIDE Weight-Loss Surgery: Your Guide for Life For you and your family. Read it before your operation, and keep it for life. |
The operation you had
☐ Sleeve gastrectomy
☐ Roux-en-Y gastric bypass
☐ One-anastomosis gastric bypass
☐ Other: ______________________
Your new life: the five golden rules
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Protein first at every meal. Aim for at least 60 g of protein a day.
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Small bites, chew well, stop when full. Use a small plate.
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Sip water between meals, not with them. Aim for about 1.5 to 2 liters a day.
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Take your vitamins every day, for life.
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Come to every follow-up visit and blood test.
1. Pain and pain medicines
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Your tummy and left shoulder may ache for a few days.
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Take only the pain medicines we gave you.
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After a bypass: never take anti-inflammatory medicines such as ibuprofen, diclofenac, or aspirin unless your team says so. They can cause ulcers.
2. Your wounds
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You can shower after 1 to 2 days. Pat the small wounds dry.
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Walk several times a day to prevent clots, and use the blood-thinning injections if prescribed.
3. Eating and drinking
[Figure — diagram omitted in this text edition; see the figure caption below and the Word chapter file for the image]
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Follow your dietitian’s plan for each stage.
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Avoid sugary drinks, sweets, and fizzy drinks.
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If food sticks or you vomit, go back to the previous stage and call us if it continues.
4. Vitamins and blood tests
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My vitamins: ______________________________________________
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Blood tests are needed at about 3, 6, and 12 months, and then every year, or as your team advises.
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Hair often thins for a few months. It grows back.
5. Getting back to normal
| Activity | Usually from |
|---|---|
| Walking | The same day. Walk more each day. |
| Driving | About 1 to 2 weeks |
| Office work or school | About 2 to 3 weeks |
| Exercise | Light from the first week; full by 4 to 6 weeks |
| Prayer | From the first day |
| Fasting in Ramadan | Usually not in the first 6 to 12 months. Ask your dietitian. |
| Pregnancy | Wait 12 to 18 months. Use reliable contraception until then. |
6. Your feelings
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Big changes in your body can bring big feelings. Many people feel happier; some feel low or anxious.
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Avoid alcohol. It affects you more strongly after surgery.
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If you feel low, hopeless, or are drinking more, tell us. Help is available.
7. Warning signs: when to get help
| Level | What you notice | What to do |
|---|---|---|
| GREEN | Mild tummy or shoulder pain that improves; feeling full quickly; tiredness; hair thinning | This is normal. Keep following this guide. |
| AMBER | Vomiting after most meals; food sticking; heartburn; feeling faint or sweaty after eating; low mood or drinking more | Call the bariatric team today. |
| RED | Fast heartbeat, fever, or worsening tummy or left shoulder pain; cannot keep any fluids down for 12 hours; severe tummy pain; black stools or vomiting blood; confusion or double vision; chest pain or a swollen leg | Go to the emergency department now. Say you have had weight-loss surgery. |
My contacts Bariatric team: ______________________ Hours: ______________ Dietitian: ______________________ Out of hours: ______________ My questions: ____________________________________________________________ [Unit name] [Guide version and review date] |
References
1. Look AHEAD Research Group. Reduction in weight and cardiovascular disease risk factors in individuals with type 2 diabetes: one-year results of the Look AHEAD trial. Diabetes Care. 2007;30(6):1374-1383.
2. Aronne LJ, Horn DB, le Roux CW, et al. Tirzepatide as compared with semaglutide for the treatment of obesity. N Engl J Med. 2025;393(1):26-36.
3. Wilding JPH, Batterham RL, Davies M, et al. Weight regain and cardiometabolic effects after withdrawal of semaglutide: the STEP 1 trial extension. Diabetes Obes Metab. 2022;24(8):1553-1564.
4. Abu Dayyeh BK, Bazerbachi F, Vargas EJ, et al. Endoscopic sleeve gastroplasty for treatment of class 1 and 2 obesity (MERIT): a prospective, multicentre, randomised trial. Lancet. 2022;400(10350):441-451.
5. Arterburn D, Wellman R, Emiliano A, et al. Comparative effectiveness and safety of bariatric procedures for weight loss: a PCORnet cohort study. Ann Intern Med. 2018;169(11):741-750.
6. Eisenberg D, Shikora SA, Aarts E, et al. 2022 American Society for Metabolic and Bariatric Surgery (ASMBS) and International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO): indications for metabolic and bariatric surgery. Surg Obes Relat Dis. 2022;18(12):1345-1356.
7. Salminen P, Grönroos S, Helmiö M, et al. Effect of laparoscopic sleeve gastrectomy vs Roux-en-Y gastric bypass on weight loss, comorbidities, and reflux at 10 years in adult patients with obesity: the SLEEVEPASS randomized clinical trial. JAMA Surg. 2022;157(8):656-666.
8. Schauer PR, Bhatt DL, Kirwan JP, et al. Bariatric surgery versus intensive medical therapy for diabetes: 5-year outcomes. N Engl J Med. 2017;376(7):641-651.
9. Mechanick JI, Apovian C, Brethauer S, et al. Clinical practice guidelines for the perioperative nutrition, metabolic, and nonsurgical support of patients undergoing bariatric procedures, 2019 update. Surg Obes Relat Dis. 2020;16(2):175-247.
10. Robertson AGN, Wiggins T, Robertson FP, et al. Perioperative mortality in bariatric surgery: meta-analysis. Br J Surg. 2021;108(8):892-897.
11. Arterburn DE, Courcoulas AP. Bariatric surgery for obesity and metabolic conditions in adults. BMJ. 2014;349:g3961.
Note: references are numbered within this chapter for the pilot. Items marked in square brackets are collected in the Author Fill-in and Verification Log.