How Much Do You Have to Weigh to Get a Gastric Bypass?

Medically Reviewed on 9/27/2022
Gastric Bypass
The long-term success of bariatric surgery depends on the person’s ability to alter their diet and lifestyle.

Most patients qualify for bariatric surgery if they weigh at least 100 lbs more than their ideal body weight. They must, however, not weigh more than 450 lbs.

A person can also qualify for the surgery if they have a body mass index (BMI) of 40 or higher or a BMI between 35 and 40 along with an obesity-related health issue, such as:

Weight loss or bariatric or metabolic surgery is used as a treatment for obese people; it can lead to significant weight loss and help improve many obesity-related conditions, such as type II diabetes or high blood pressure.

What is a gastric bypass?

Bariatric surgery is a long-lasting weight-loss solution for obese patients that makes changes to the shape and function of the stomach and digestive system, which either limits the amount of food eaten or the nutrients absorbed.

Types of weight loss surgeries

  • Duodenal switch: A major part of the stomach (about 80 percent) is removed, and the stomach is connected to the duodenum (the first portion of the small intestine).
  • Gastric sleeve or sleeve gastrectomy: A large portion of the stomach is removed to create a tube-like sleeve to limit the amount of food eaten and make the patient feel full sooner.
    • A smaller stomach also produces fewer hormones that affect appetite. The combination of being able to eat less and wanting to eat fewer results in significant weight loss.
  • Roux-en-Y gastric bypass: The stomach is stapled into two pieces, which speed the flow of food into the intestine and alter the gut hormones that influence feelings of hunger and fullness.
    • The gastrointestinal tract is altered by attaching the smaller section of the stomach to the small intestine.
    • It is considered a “metabolic” procedure because it changes the way the body absorbs fat, calories, and nutrients.


What is weight loss surgery? See Answer

What are the eligibility criteria for a gastric bypass?

The body mass index (BMI) is calculated using weight and height to estimate body fat. 

The eligibility criteria for gastric bypass or weight-loss surgery include:

  • A BMI of 40 or higher with or without comorbidities
  • A BMI of 35 to 39.9, with an obesity-related condition, such as heart disease, diabetes, high blood pressure, or severe sleep apnea
  • Weight of 100 lbs more than the ideal body weight
  • Unable to achieve a healthy body weight for a sustained period (at least six months), even after supervised weight-loss attempts
  • Obesity-related conditions that could be life-threatening, if left untreated 
  • No medical conditions that may put a patient at risk during and after surgery

What are the benefits of weight-loss surgery?

The long-term success of bariatric surgery depends on the ability to make permanent changes in diet, behavior, and exercise.

Studies have reported that people who undergo bariatric surgery:

  • Live longer.
  • Have reduced cardiovascular risk.
  • Have less sleep apnea and joint-related pain.
  • Enjoy an improved quality of life.

What are the risks involved in weight-loss surgery?

Weight-loss surgery carries a risk of complications, such as:

Weight-loss surgery is likely to be avoided or considered high-risk if the individual has the following:

  • Blood-clotting disorders
  • Severe heart disease that prohibits the use of anesthesia
  • Other conditions that may increase the risk of using anesthesia
Medically Reviewed on 9/27/2022
Image Source: iStock image

Am I a Candidate for Weight Loss Surgery? Cleveland Clinic:

Qualifications for Bariatric Surgery. Temple Health:

Weight-loss surgery: Is it an option for you? Mayo Clinic:

Weight Loss Surgery Options. Duke Health: