Learn about the criteria you must meet to have this weight-loss surgery.

By Mayo Clinic Staff

Gastric bypass surgery is the most common type of weight-loss surgery. Gastric bypass and other types of weight-loss surgery, collectively known as bariatric surgery, make surgical changes to your stomach and digestive system that limit how much food you can eat and how many nutrients you absorb, leading to weight loss.

While that may sound appealing, gastric bypass surgery isn't for everyone. Like any major procedure, it has significant health risks and side effects. In addition, the long-term success of gastric bypass surgery depends on your ability to make permanent changes in your lifestyle. When you want to be considered for gastric bypass surgery, you must undergo a thorough evaluation to determine if it's suitable for your situation.

Gastric bypass and other weight-loss surgeries are major, life-changing procedures. While weight-loss surgery can help reduce your risk of weight-related health problems — such as type 2 diabetes, high blood pressure and sleep apnea — it can also pose major risks and complications. You may need to meet certain medical guidelines to qualify for weight-loss surgery. You likely will have an extensive screening process to see if you qualify.

In general, gastric bypass and other weight-loss surgery could be an option for you if:

  • Efforts to lose weight with diet and exercise have been unsuccessful
  • Your body mass index (BMI) is 40 or higher (extreme obesity)
  • Your BMI is 35 to 39.9 (obesity) and you have a serious weight-related health problem, such as type 2 diabetes, high blood pressure or severe sleep apnea

In some cases, you may qualify for certain types of weight-loss surgery if your BMI is 30 to 34 and you have serious weight-related health problems.

Even if you meet these general guidelines, you still may need to meet certain other medical guidelines to qualify for weight-loss surgery. You likely will have an extensive screening process to see if you qualify.

A team of health professionals — usually including a doctor, dietitian, psychologist and surgeon — evaluate whether gastric bypass or one of the other forms of weight-loss surgery is appropriate for you. This evaluation generally determines if the health benefits of the surgery outweigh the potentially serious risks. The evaluation also determines if you're psychologically and medically ready to undergo the procedure.

When conducting an evaluation for gastric bypass surgery, the health team considers:

  • Your nutrition and weight history. The team reviews your weight trends, diet attempts, eating habits, exercise regimen, stress level, time constraints, motivation and other factors.
  • Your medical condition. Some health problems increase the risks associated with having surgery or may be worsened by surgery, such as blood clots, liver disease, heart problems, kidney stones and nutritional deficiencies. The team evaluates what medications you take, how much alcohol you drink and whether you smoke. You also will have a thorough physical exam and laboratory testing. The results of these tests and exams may help determine eligibility for weight-loss surgery.
  • Your psychological status. Certain mental health conditions may contribute to obesity or make it more difficult for you to maintain the health benefits of gastric bypass surgery. These may include binge-eating disorder, substance abuse, depression, anxiety disorders and issues related to childhood sexual abuse. While these may not prevent you from having gastric bypass surgery, your doctors may want to postpone surgery to ensure that any condition is appropriately treated and managed.
  • Your motivation. The team will also assess your willingness and ability to follow through with recommendations made by your health care team and to carry out prescribed changes in your diet and exercise routine.
  • Your age. Although there's no specific age limit for gastric bypass surgery, the risks increase as you get older. The surgery remains controversial in people under age 18.

If you're approved for gastric bypass surgery, your health care team gives you instructions about how to prepare in the months or weeks before the surgery. These instructions may include restrictions on eating and drinking, undergoing lifestyle counseling to help you cope with big changes in diet and exercise, quitting smoking, and starting a supervised physical activity or exercise program. In some cases, you may be required to lose weight before having gastric bypass surgery.

Even after gastric bypass surgery is scheduled, it can be delayed or canceled if your health care team determines that:

  • You're not psychologically or medically ready for surgery
  • You haven't made appropriate changes in your eating or exercise habits
  • You gain weight during the evaluation process

If it's determined that gastric bypass surgery is appropriate for you, you will still have financial hurdles to negotiate. If you plan to rely on health insurance coverage for your gastric bypass surgery, you likely need to get preapproval from your health insurance company, Medicare or your state medical assistance program — whoever you have insurance through. The preapproval process typically requires documentation from your team of doctors that justifies your medical need for gastric bypass surgery.

Different health insurers have different requirements to prove your medical need for gastric bypass surgery. Your health insurer may not cover gastric bypass surgery at all or may cover only parts of the process. To avoid unpleasant financial surprises, it's a good idea to check to see what specific services are covered before starting the evaluation process. You may have to pay for some portion of the costs yourself.

Gastric bypass surgery isn't a miracle procedure — and it isn't for everyone. Having gastric bypass or other weight-loss surgery doesn't guarantee that you'll lose all your excess weight or that you'll keep it off over the long term. Nor is it a way to avoid making changes in your diet and exercise habits. In fact, you can regain the weight you lose with gastric bypass surgery if you don't stick with the lifestyle changes. But if you think gastric bypass surgery might be right for you, talk with your doctor.

Sep. 18, 2014