Obesity surgery

Obesity is a chronic disease that is linked to a wide range of health problems and to reduced life expectancy.

Surgery is the most durable and effective treatment for severe obesity#

Surgery should be considered in people who have a BMI above 40, or a BMI above 35 together with associated health problems such as diabetes.

As well as producing weight loss, obesity surgery often improves obesity-related health problems and quality of life. Modern operations are performed using keyhole (minimally invasive) techniques and are considered very safe, with complication rates of around 1 to 5 per cent depending on the type of surgery.

Surgery is best thought of as a tool#

To achieve good long-term results, it is very important that patients are supported throughout their weight-loss journey so they can make permanent changes to their eating habits and lifestyle. A typical obesity surgery service includes a team of health professionals, which may involve surgeons, dietitians, nurses and psychologists.

Measuring overweight and obesity#

There are several ways to categorise the degree of overweight and obesity. A popular and simple method is the body mass index (BMI). To calculate it, divide your weight in kilograms (kg) by your height in metres squared (m²).

A person with a BMI of 40 or more is at a much higher risk of obesity-related disorders such as diabetes, reduced mobility or high blood pressure.

A commonly used set of categories is:

• Less than 20 – underweight
• 20 to 25 – normal weight range
• 25 to 30 – overweight
• 30 to 35 – mild obesity
• 35 to 40 – moderate obesity
• More than 40 – severe obesity

For example, if you weighed 110 kg and were 1.55 m tall:

• Work out your height in metres squared (1.55 m × 1.55 m = 2.4 m²)
• Divide your weight by that figure (110 kg ÷ 2.4 m² = 45.8)
• Your BMI would be 45.8

BMI should only be used as a guide.

Common obesity surgery techniques#

The most common obesity operations include gastric banding, sleeve gastrectomy and gastric bypass. Gastric banding was the predominant operation for several decades but has now largely been replaced by sleeve gastrectomy and gastric bypass.

Gastric banding#

Gastric banding involves placing a plastic ring around the top of the stomach. The ring is connected by thin plastic tubing to a port placed under the skin. By adding or removing water through the port, the band can be made tighter or looser.

People with a gastric band need to eat slowly and chew their food very well. Eating red meat or bread is often problematic. Gastric bands can be both inserted and removed using keyhole techniques.

Sleeve gastrectomy#

Sleeve gastrectomy is now the most commonly performed obesity operation. It is a keyhole operation that removes a portion of the stomach, reducing it to roughly the size of a banana.

As well as restricting how much can be eaten, this surgery alters the hormonal signalling between the gut and the brain. Patients experience markedly reduced hunger, eat small meals and, as a result, lose a large amount of weight. Some people experience increased heartburn symptoms after a sleeve gastrectomy.

Gastric bypass#

Several types of operation fall into this category, including Roux-en-Y gastric bypass (RYGB) and one anastomosis (or “mini”) gastric bypass (OAGB-MGB). All combine creating a small section of stomach to receive food with bypassing (“short-cutting”) the first part of the small intestine.

Like the sleeve, these operations alter the signalling between the gut and the brain to reduce hunger. Patients can eat a wide range of foods, but particularly rich or heavy foods may cause queasiness, sweating and diarrhoea (“dumping syndrome”).

Obesity is a complex disease, not a personal failing#

Most people considering obesity surgery have lived with obesity for much of their lives and have endured cycles of dieting, weight loss and weight regain. Sadly, a stigma persists that obesity is self-inflicted. In reality, it is a complex chronic disease involving genetics, environment, hormones, upbringing, cultural background, socioeconomic status and psychological distress.

Undergoing obesity surgery is a big step. It is certainly not “cheating” or “the easy way out”. An obesity surgery journey includes a comprehensive medical assessment, preparation with a special low-calorie diet, months of restricted eating after surgery, and a commitment to long-term follow-up with dietitian input, vitamin supplements and regular blood tests. It is a challenging but ultimately rewarding journey for most patients, leading to a longer, healthier life.

The health risks associated with severe obesity include diabetes, heart disease, high blood pressure, sleep apnoea, depression, arthritis and certain cancers.

Key points#

• Obesity surgery is the most durable and effective treatment for severe obesity
• Gastric bands can be inserted and removed by keyhole techniques
• Sleeve gastrectomy is now the most commonly performed obesity surgery procedure
• Some patients can experience increased heartburn symptoms after a sleeve gastrectomy

Where to get help#