What type of bariatric surgery is best for me?

Obesity is a serious problem not just in Singapore but worldwide. Not only is obesity associated with poorer mental health and reduced quality of life, it’s also one of the leading causes of health conditions like diabetes, stroke, heart disease and certain types of cancer. 

Apart from the standard weight loss protocol, bariatric surgery or weight loss surgery is something severely obese options can consider. It involves changing the anatomy or position of the stomach and small intestines. Doing so causes a decrease in appetite and food absorption, thereby leading to weight loss. 

There are a few types of bariatric surgery procedures to choose from. How can you decide which is best for you? In this article, I will compare the two bariatric procedures most commonly performed in Singapore: a gastric bypass and sleeve gastrectomy.

Do I qualify for bariatric surgery?

While a surgery to help with weight loss might come across as enticing to anyone regardless of shape or size, not everyone can qualify. You are eligible for bariatric surgery in Singapore if: 

  • You are extremely obese with a BMI of 40 or higher 
  • You have a BMI of 35-40 and and have an obesity-related condition like diabetes, high blood pressure, fatty liver disease, high cholesterol or sleep apnea 
  • You have tried losing weight using conventional means to no avail 

If you qualify for bariatric surgery, the next step is to decide which procedure is best for you. This depends on factors like your medical history, conditions and expectations and should be discussed with your doctor. Regardless, most doctors today including myself perform almost all bariatric procedures using minimally invasive techniques i.e. laparoscopic surgery, meaning smaller incisions are made instead for faster recovery and fewer postoperative complications.

Gastric bypass surgery

How it works: The laparoscopic Roux-en-Y gastric bypass surgery involves disconnecting the top part of the stomach and making a small pouch there. We then connect a loop of a small intestine up to the pouch, rerouting the gastrointestinal tract. This new arrangement allows food to bypass about 90-95% of the stomach and enter the small intestine directly. As a result, the patient consumes a significantly lesser amount of food and calories. 

Pros: Weight loss tends to be pretty swift and effective. About 65% of it happens in 6 months to a year and I’ve seen patients keep at least 50% of the initial weight loss off. Studies have also shown that with proper adherence to diet, long term weight loss is sustained even after 5, 10 or 15 years. In addition, because rerouting the GI tract leads to favourable hormonal changes, laparoscopic Roux-en-Y gastric bypass surgery is especially effective in treating Type II diabetes. About 86% of patients see a reversal or improvement in their diabetes and 78% experience remission. 

Cons: Because food is not absorbed the same way, there runs a risk of malnutrition. Patients have to be very careful with their diet and take multivitamins and supplements for the rest of their life.

Who it’s good for

People with severe acid reflux disease

Acid reflux often improves after Roux-en-Y gastric bypass surgery 

People with high BMIs and an obesity-related condition

After gastric bypass surgery, food high in sugar and fat are poorly tolerated by the body. When consumed, patients experience dumping syndrome or unpleasant symptoms such as abdominal discomfort, nausea and palpitations. These symptoms will then discourage patients from consuming sweet and fatty foods, which are often unhealthy and high in calories.

Sleeve gastrectomy

How it works: A gastric sleeve gastrectomy involves removing about 80-85% off the stomach, leaving the remaining 20% of the stomach in a “sleeve” shape. 

Pros: With a smaller stomach, patients eat less and feel full a lot sooner. Ghrelin, a hormone in the stomach associated with hunger, is also removed so hunger pangs or the urge to eat is significantly reduced. On average, patients lose about 60-70% of their excess weight over 6 months to a year. As a sleeve gastrectomy is a simpler operation compared to a gastric bypass, it is better for those who are severely obese or sick. 

Cons: Unlike gastric bypass surgery, a sleeve gastrectomy is irreversible. 

Who it’s good for: 

People with a history of multiple abdominal surgeries 

Someone who has had multiple abdominal surgeries would most likely have severe scar tissue. Rerouting the GI tract and operating on the small intestine as with a gastric bypass surgery would be impossible. In a sleeve gastrectomy, we only work on the upper part of the abdomen, which is usually less affected by scar tissues. 

Severely obese people who weight more than 200-300 kg 

For patients who are extremely obese, other weight loss surgeries might be too risky. Rerouting the GI tract is also impossible as there is not enough space inside the abdomen. 

High risk surgical patients 

These include patients with severe heart disease, lung problems and transplant candidates. A sleeve gastrectomy carries shorter anaesthesia and recovery time. 

People on multiple medications to treat illnesses like depression 

As a gastric bypass can affect how your body absorbs and responds to medication, a sleeve gastrectomy is better for someone with say severe depression or anxiety and reliant on multiple psychiatric medications.


  1. Brocks, D. R., Ben-Eltriki, M., Gabr, R. Q., & Padwal, R. S. (2012). The effects of gastric bypass surgery on drug absorption and pharmacokinetics. Expert opinion on drug metabolism & toxicology, 8(12), 1505–1519. https://doi.org/10.1517/17425255.2012.722757
  2. Puzziferri, N., & Almandoz, J. P. (2018). Sleeve Gastrectomy for Weight Loss. JAMA, 319(3), 316. https://doi.org/10.1001/jama.2017.18519

Leave A Comment