Medical guidelines

The general medical guidelines for weight-loss surgery are based on body mass index (BMI). BMI is a formula that uses weight and height to estimate body fat. In the U.S., weight-loss surgery generally may be an option for an adult with a BMI of 40 or higher.

A surgeon also may recommend surgery if your BMI is between 35 and 40 and you:

• Have metabolic syndrome. This means you have one or more conditions that increase the risk of heart disease, stroke and type 2 diabetes. These conditions include high blood pressure, high blood sugar, too much fat around the waist, and high cholesterol or triglyceride levels.
• Have type 2 diabetes. Type 2 diabetes happens when the body can't use insulin correctly and sugar builds up in the blood.
• Have not been able to lose enough weight by improving your exercise or eating habits to treat other weight-related conditions. Examples of weight-related conditions are heart disease, obstructive sleep apnea and high cholesterol levels.

Bariatric surgery also may be considered for some people with BMIs in the 30 to 35 range. There is no specific age limit for weight-loss surgery. People older than 65 after weight-loss surgery have similar results as younger people do. Weight-loss surgery may be an option for some children and teens who have:

• BMIs of 40 or higher and any weight-related health condition.
• BMIs of 35 or higher and a serious weight-related health condition.

Instead of using these BMI numbers as a guideline for surgery, surgeons may use growth charts for children and teens. These charts show the standard BMI range for each age. A surgeon may recommend surgery based on how much an adolescent's BMI is above the standard BMI range.

Depending on the type, severity or risk of a weight-related illness, some adults and teens with lower BMIs may be candidates for weight-loss surgery.