Facts and Figures

Weight loss surgery is the most effective treatment for those with chronic weight problems who have been unable to achieve and maintain weight loss by other methods.

Weight loss surgery is not an admission of failure!


This type of surgery reduces health risks, improves mobility, restores self-confidence, self-esteem and gives the patient a much improved quality of life. It also extends their life expectancy.

Weight loss surgery is not an admission of failure. Regulation of the appetite in humans is an extremely complex process and is not yet fully understood. It is controlled by many chemical and hormonal messengers and this means that some individuals are unable to control their appetite in the normal way.

A person's suitability for weight loss surgery is determined by their BMI (Body Mass Index). BMI describes a person's weight relative to their height and correlates strongly with the body fat content. Check your BMI using the calculator provided at the top right of this page.

For the majority of people, weight loss surgery is not a high-risk option. Whatever small risks there are must be set against the potentially dramatic benefits you can expect to gain.

BMI Category Risk of associated co-morbidities*
18.5 or less Underweight N/A
18.5 - 24.9 Normal Low
25.0 - 29.9 Overweight Increased risk
30.0 - 34.9 Obese High risk
35.0 - 39.9 Obese Very high risk
40.0 or more Morbidly Obese Extremely high risk


* These are health risks which can include hypertension, diabetes, osteoarthritis, heart disease and sleep apnoea.

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More about weight loss surgery from Spire Thames Valley


Read our weight loss surgery FAQs

Benefits of weight loss surgery

What do I do now?

© Spire Healthcare Group plc (2016)