Bariatric surgery, also known as metabolic surgery or weight loss surgery, is a surgical intervention for obesity.
This type of surgery has been proven to be more effective than lifestyle, dietary and medical interventions in the management of obesity. It modifies different parts of the gastrointestinal (digestive) tract to bring about weight loss.
Types of bariatric surgery
There are 4 types of minimally invasive bariatric surgery:
Laparoscopic adjustable gastric banding (LAGB), used to manage morbid obesity. This surgery reduces the size of your stomach by placing a silicone band around the upper end of the stomach. You should feel full faster, eat less, and thus lose weight.
Laparoscopic sleeve gastrectomy(LSG), used to permanently reduce the size of your stomach to about 25% its original size, such that it resembles a sleeve or a tube.
LaparoscopicRoux-en-Y gastric bypass(LRYGB), used to reduce the size of your stomach to a small pouch by clipping off a section of it. This small pouch is then directly attached to the small intestine, bypassing the rest of the stomach and the upper end of the small intestine.
Laparoscopic biliopancreatic diversion with duodenal switch, used to reduce your stomach to about 25% of its original size, such that it resembles a sleeve or a tube. In this procedure, the middle section of the small intestine is clipped and the last part of the small intestine is attached directly to the duodenum. The separated middle section is reattached to the end of the intestine, bypassing most of the small intestine.
Why do you need bariatric surgery?
Bariatric surgery can successfully manage your weight and greatly improve obesity-associated disorders, such as:
Hyperlipidaemia (high levels of lipids in the blood)
To qualify for gastric bypass, your body mass index (BMI) must be:
More than 32.5, and you must have an obesity-associated disorder such as Type 2 diabetes.
More than 37.5.
Weight loss surgery can help you to enjoy a better quality of life and a longer lifespan. It can also help to prevent future health problems. However, you must be willing to make lifelong lifestyle changes to benefit from bariatric surgery.
Who should not undergo bariatric surgery?
Bariatric surgery may not be suitable for everyone who is severely overweight. You need to meet certain medical requirements to qualify for weight-loss surgery.
Your doctor will determine:
Whether you are a suitable candidate
Which procedure is best for you
What are the risks and complications of bariatric surgery?
Bariatric surgery is considered safe in general. There are some inherent risks as with all major surgery, such as:
Adverse reactions to anaesthesia
Blood clots and deep vein thrombosis
Intestinal leaks in staple line or joints
Lung or breathing problems
Depending on the type of surgery, long-term complications of bariatric surgery may include:
Dumping syndrome, causing diarrhoea, nausea or vomiting
In the long-term, you may not lose the weight you hoped for and the weight may return. This usually happens if you do not stick to your doctor’s recommendations or fail to make the required lifestyle changes including adopting a healthy eating habit and regular exercise regime.
How do you prepare for bariatric surgery?
Once your doctor has cleared you for bariatric surgery, they will give you instructions on how to prepare yourself for the procedure.
You may be asked to:
Undergo blood tests, X-rays, scans and physical examinations
Observe diet restrictions on certain foods and drinks
Stop certain medications
Start an exercise regime
You may also have to plan ahead for your post-surgery recovery by arranging for help at home, if necessary.
What can you expect in bariatric surgery?
Bariatric surgery requires a high level of preparation to ensure a safe and successful surgery.
Bariatric surgery usually lasts several hours.
Before the procedure
As bariatric surgery involves your stomach, your diet in the days leading to the procedure is especially important.
Starting from 2 days before surgery, you will begin a clear liquid diet to prepare your digestive tract for surgery. This ensures that your stomach and intestines are mostly empty and that you remain hydrated.
Clear liquid food and drink options include:
Strained soups with no solids
Protein drinks, but please check with your doctor first
You must refrain from all sugary, fatty and alcoholic food and beverages.
Around noon on the day before surgery, you will consume laxatives to clear your bowel.
From midnight before surgery, you must fast from all foods and drinks. You must also avoid swallowing water while brushing your teeth and rinsing.
During the procedure
All bariatric surgery is done using general anaesthesia. This means you will be asleep during surgery and will not feel any pain.
While some weight-loss surgeries are done with traditional large incisions in your abdomen, most types of bariatric surgery are performed using a laparoscope. This is a small, tubular instrument with a camera attached. Your surgeon will make small incisions in your abdomen and insert the laparoscope to navigate and perform the procedure on your stomach.
After the procedure
You will be transferred to a recovery room, where you will be closely monitored. Depending on the procedure, you may need to stay for a few days in the hospital.
You may not be allowed to eat for 1 – 2 days to allow your stomach and digestive system to heal. You will be on a water-only diet.
Care and recovery after bariatric surgery
After going through bariatric surgery, you will need to make the following lifestyle changes to recover smoothly and avoid putting on weight.
You will be on a liquid or soft food diet in the weeks after the surgery. You will gradually progress to a normal, balanced diet which you need to follow permanently.
During your recovery, you are advised to:
Eat slowly and chew carefully.
Only eat small amounts at a time.
Avoid foods that can block your stomach, such as soft white bread.
Take vitamin and mineral supplements.
Once you have recovered from your surgery, you need to start an exercise plan and maintain it for life. The aim is to help you lose as much weight as possible after the operation.
Below are some moderate to vigorous physical activities to keep your heart rate up and burn fats:
Gardening or housework
Regular follow-up appointments
You will be asked to attend regular follow-up appointments to monitor your health, especially for the first 2 years. After that, a check-up with a general practitioner once a year will suffice.
During follow-up appointments, your doctor may order:
Blood tests to check your vitamin and mineral levels
A physical health check
Your doctor may also advise you on your diet and exercise. Learn more about bariatric surgery and the post-surgery recovery process.
Pregnancy and contraception
Women are usually advised to avoid becoming pregnant in the first 12 – 18 months after bariatric surgery. Weight loss surgery can negatively affect your vitamin and mineral levels, which could harm your baby.
You will be advised to:
Use contraception until your doctor advises that it is safe to become pregnant. Check with your doctor about the best type of contraceptives, as not all are suitable for women post-bariatric surgery.
Speak to your doctor if you become pregnant within 12 – 18 months after surgery. They can help check your vitamin and mineral levels, and recommend supplements to take.
Frequently asked questions
A: Yes, weight loss surgery is very safe in general. However, like all major surgery, risks and complications may include:
More than 32.5, and you must have an obesity-associated disorder such as type 2 diabetes.
More than 37.5.
We do not currently advocate surgery for diabetics with a BMI less than 27 or those not considered overweight. Bariatric surgery has been proven by clinical trials to reverse type 2 diabetes, but these studies were only done on diabetic patients who are also obese. There are some ongoing researches into the efficacy of surgery in low BMI diabetics that may shed light on the role of bariatric surgery for non-obese diabetic patients in the future.
In one long-term study that tracked 400 people with type 2 diabetes, 62% showed no signs of diabetes 6 years after bariatric surgery. They also showed improved blood pressure, cholesterol, and triglyceride levels.
A:1 – 2 days after bariatric surgery, you will be on a water-only diet. You will not be allowed to eat to allow your stomach and digestive system to heal.
Weeks after the surgery, you will be on a liquid or soft food diet. You will gradually progress to a normal, balanced diet which you need to follow permanently.
In the long term:
You should avoid eating fried potatoes, rice and pasta as they may make you feel bloated or gassy. Try to eat at least 60 – 80 grams of protein every day to prevent muscle and hair loss. Also, try to consume more non-starchy vegetables such as broccoli, cauliflower or spinach.
You may develop food intolerances that you did not have before the surgery, such as:
Oily, high-fat foods
Red meat that is tough or dry
Spicy or heavily seasoned foods
Sugar alcohols such as erythritol, glycerol, mannitol, sorbitol and xylitol
Food heated up in the microwave
A: After your gastric bypass surgery, your doctor will provide tailored advice for your diet and meal sizes. You may refer to the general guidelines below for an idea of how much to eat and drink at each recovery stage:
1 day after surgery. To avoid dehydration, you should drink about 1.5 – 2 litres of liquid daily. Sip liquids between meals, not together with meals. Avoid drinking 30 minutes before a meal, and wait at least 30 minutes before drinking after a meal.
1 week of a liquid diet. You can eat 3 – 6 small meals daily, with each meal containing about 4 – 6 tablespoons of food.
A few weeks of pureed food. You can eat 3 – 5 small meals daily, with each meal containing about one-third to one-half cup of food.
2 months after your surgery. You can start eating 3 meals a day, with each meal containing about 1 – 1.5 cups of food. You should stop eating before you feel completely full. Depending on your response to solid food, you may be able to adjust:
A: Many patients experience loose or sagging skin after bariatric surgery, as skin might not tighten fully after rapid and massive weight loss.
The most effective tightening is accomplished through body contouring surgery. During this procedure, excess skin is cut off using long incisions to minimise scarring.
To help your skin tighten naturally, you may also:
Consume a balanced and nutritious diet
Take recommended supplements such as collagen
Exercise to build muscle mass
Apply firming creams
A: General surgeons who specialise in performing different types of bariatric surgery.
A: The risk of dying from bariatric surgery is extremely low.
In addition, the long-term benefits of bariatric surgery outweigh the risks. Compared to morbidly obese individuals who did not undergo gastric bypass surgery, those who underwent gastric bypass surgery had an 89% lower risk of death over the next 5 years.
A: Bariatric surgery is the most effective method for losing weight, treating conditions related to obesity, and maintaining weight loss.
It is more effective than lifestyle, dietary and medical interventions in the management of obesity. It modifies different parts of the digestive tract to bring about rapid and massive weight loss.
However, to avoid weight gain in the long term, you must make lifestyle changes such as healthier eating habits and regular exercise. Surgery alone is not the answer.
Discuss with your specialist to decide if weight loss surgery is right for you.
A: A gastric band placed around the upper end of your stomach can help reduce the size of your stomach. After your surgery, you will feel full faster, eat less and thus lose weight.
A: A gastric band is intended to be life-long and permanent. Your doctor will only recommend removing it if complications develop.
Why choose Mount Elizabeth Hospitals?
At Mount Elizabeth Hospitals in Singapore, we are committed to giving you comprehensive care and medical advice in a private and personalised setting.
Our multidisciplinary team of surgeons, nurses and dietitians are here to guide you through the entire bariatric surgery process from pre-surgery diet and exercise preparation to post-op recovery.
Our general surgeons
Mount Elizabeth's panel of general surgeons are skilled and experienced in performing bariatric surgery to lower the risks of obesity-related disorders.
They are supported by a team of dietitians and nurses who will work closely with you for a smooth recovery and long-lasting change in your health.