How Weight Loss Surgery Works

Weight loss surgery changes your digestive process by closing off parts of the stomach. Making the stomach smaller means you feel full after eating less food.


Types of Bariatric Procedures

Restrictive operations reduce stomach size, therefore restricting the amount of food the stomach can hold.

Malabsorptive operations combine restriction with a partial bypass of the small intestine (where food and nutrients are absorbed into the body). This "detour" restricts the amount of food the intestine can absorb.

There are a number of restrictive and malabsorptive procedures that are FDA-approved. Three bariatric procedures are performed here at BIDMC.

RNY Gastric Bypass Lap Adjustable Gastric Band Gastric Sleeve

Am I Eligible for WLS?

Patients must meet specific criteria, based on guidelines established by the National Institutes of Health, before they will be considered for an evaluation with our team. Most patients who enter our program have a BMI of 40 or greater. Other factors that suggest surgery may be a good option include:

  • You are a minimum of 100 pounds overweight.
  • You have a BMI over 40.
  • You have serious medical conditions related to weight, such as diabetes, sleep apnea or heart disease. (If these are present, surgery may be considered if your BMI is between 35 and 40.)
  • You are between 18 and 65 years old (with some exceptions).
  • You have a long history of obesity, with many failed formal, structured and/or documented attempts at weight loss.
  • You have no current issues with drug or alcohol abuse.
  • You have no serious psychiatric illness, such as problems that could impair your ability to follow a program of lifetime health management and follow-up.

If you are not eligible for weight loss surgery, BIDMC also offers a non-surgical procedure that may be right for you.

Learn more about the intragastric balloon


New Patient Form

If you are interested in exploring your options for weight loss surgery and becoming a patient at BIDMC, please fill out the form below.

Patient Intake Form

You can bring this to your first appointment or scan and email it to: wls@bidmc.harvard.edu. You can also fax it to 617-667-2866.