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What is weight loss surgery?

Weight loss surgery is also known as bariatric surgery. It is an option for some people who have not been able to lose weight through traditional means such as diet and exercise. There are 2 main types of bariatric surgery:
  • Restrictive
  • Combined restrictive and malabsorptive
Restrictive procedures promote weight loss by making the stomach smaller and reducing the amount of food intake.

Combined restrictive and malabsorptive procedures cause weight loss by making the stomach smaller and bypassing part of the small intestine and not absorbing as much food.

Is weight loss surgery right for everyone?

No. Surgery is not the solution for everyone. The Bariatric Team will determine whether you are right for surgery after a complete evaluation and discussion with you. Weight loss surgery is a life-altering procedure and you need to be committed to making the lifestyle changes needed for a successful outcome.

How is eligibility determined?

In order to determine a person’s eligibility for weight loss surgery, Body Mass Index (BMI) is used as one criterion. This is a mathematical calculation of weight in relation to height. A person is a candidate for surgery if he or she:
  1. has failed previous attempts at weight loss in a medically supervised program
  2. has a Body Mass Index:
    • over 40 or
    • between 35 and 40 with obesity-related medical problems

Am I too old or too young to qualify for weight loss surgery?

The main criteria are related to health rather than age. People over age 65 do have weight loss surgery. The average age of a weight loss surgery person is 41. There is an increased risk of complications after surgery as you become older.

Adolescents can also have this type of surgery at specified Bariatric Centres of Excellence. Adolescents have different criteria than adults such as reaching certain height and growth stages.

What are the health benefits of weight loss surgery?

There are many reasons why weight loss surgery is healthy. Each person is different and you should talk to your health care team about this. Some of the benefits are:
  • improved or resolved Type 2 diabetes
  • reduced risk of complications caused by Type 2 diabetes such as blindness, limb amputation, kidney disease and stroke
  • lower cholesterol
  • improved blood pressure
  • improved or resolved sleep apnea (breathing problems during sleep)
  • reduced joint pain
  • improved stress continence
  • less heartburn
  • improved mood and self-esteem
  • more energy
  • longer life

What are the risks of weight loss surgery?

All surgery comes with risks and the risks are different for each person. The risks of surgery will be explained by the surgeon. You can also find more about the advantages and disadvantages (risks) of each surgery on this website. For more information, please read our Bariatric Surgery section.
Can a woman become pregnant after weight loss surgery?
Women need to avoid pregnancy for at least 18 months after surgery. It is important to talk to your surgeon about this before planning any surgery.

How much weight can a person lose and will weight loss be quick?

This depends on the type of surgery. Generally a person having: Each person is different and loses weight at a different rate. It also depends on how well a person follows his or her treatment plan, diet and lifestyle changes how much weight is lost, how fast it is lost and for how long.

Can the weight be gained back?

Yes, you can regain some of the weight. Losing weight and keeping it off depends on how well you follow your diet, exercise and supplement program. Surgery is one tool that helps but lifestyle changes are also important. Long term follow-up with your Bariatric Team is also needed.

Can a person who has had previous bariatric surgery and regained weight have another procedure?

"Redo” or revision surgery is possible but is not safe for everyone. The risk of problems and complications is higher than for first-time bariatric surgery. The Bariatric Team assesses each person on follow-up visits and tries to help the person achieve his or her goals without surgery. Since diet and exercise play the most important role in weight loss success, the Team encourages each person to do his or her part as well.

What do I need to stop doing before surgery and why?

To get ready for surgery and be in the best health possible to recover you need to make some lifestyle changes before surgery. Members of your health care Team will advise you as to your plan before surgery. Generally you must stop:
  • smoking
  • using non-prescription or illicit drugs
  • drinking alcohol, beer and wine
  • consuming caffeine
  • drinking carbonated beverages
Smoking is unhealthy for many reasons. It can delay wound healing due to poor blood flow and lead to problems such as lung infections and pneumonia. You need to stop smoking 6 months before surgery and no smoking after.

For help to quit smoking, contact Smokers’ Helpline: Non-prescription or illicit drugs are unhealthy for many reasons. They can cause problems with medications you need to take before, during and after surgery. Some also increase appetite and this can impair your ability to follow your diet. You need to stop non-prescription medication drug use 6 months before surgery and none after.

Alcohol irritates the lining of the stomach and can cause liver damage. When you lose weight fast, your liver takes up waste products and toxins produced in your body. This puts stress on your liver and can cause many problems. If you drink alcohol, you will feel the effects very fast. Alcohol may also cause Dumping Syndrome if you have Roux-en-Y Bypass surgery. You must stop drinking alcohol, beer and wine 2 months before surgery and continue to not drink for at least 3 months after. After surgery, alcohol irritates the lining of your stomach pouch. It is also high in calories and sugar. After surgery, your stomach pouch is not able to break down the alcohol and your blood absorbs it very fast. This means that you feel the effects quickly and can become intoxicated after a very small amount. This is not safe for many reasons. Your doctor or dietitian will tell you if or when you can have alcohol again.

Caffeine irritates the lining of the stomach. Since you will have a very small, new stomach, you cannot have caffeine. Stopping caffeine can take some time. When you first stop, you may get a headache and feel tired. This is called withdrawal. You need to withdraw from caffeine at least 2 months before surgery so you do not have this problem after surgery. You will not be able to have caffeine for at least 3 months after surgery as well. However, you may have decaffeinated drinks. Your doctor or dietitian will tell you if or when you can have caffeine again.

Carbonated beverages can cause problems after surgery, as they produce gas in the small stomach pouch. Most people find this very painful. You need to stop drinking carbonated drinks 2 months before surgery to get you use to not drinking carbonated drinks after surgery.

How long does it take to schedule surgery?

It takes several months to meet with the Bariatric Team for assessment and various tests. During this time it is important for you to continue to focus on weight loss and health to prepare for surgery.

What is the length of time I stay in hospital after surgery?

This depends on the type of surgery you have:
  • 3 days for gastric bypass
  • 2 to 3 days for gastric sleeve
  • 1 day for gastric banding
It is important to talk to the members of the Bariatric Team about this before surgery. The length of stay also depends on whether you develop any complications after surgery.

When can I return to work or school after surgery?

The usual time off work or school is:
  • 4 to 5 weeks for gastric bypass
  • 4 to 5 weeks for gastric sleeve
  • 1 to 2 weeks for gastric banding
When you return to work or school depends on the type of activity you do and how you feel during recovery. It is important to talk to the members of the Bariatric Team about this before surgery. This is also part of the conversation you have during follow-up visits. Each person’s plan is different.

Do I have to take supplements?

Yes, you will have to take a multivitamin and calcium supplement everyday. Other vitamins may also need to be added depending on your nutritional status. Your blood will be checked several times in the first year to see if you need to take any other vitamins or supplements. Your Bariatric Team works with you to make sure you get the best nutrition possible to stay healthy.

If I have diabetes will surgery help?

Weight loss surgery has been shown to improve Type 2 diabetes but not Type 1. 

In Type 2 diabetes, the degree of change depends on the type of bariatric surgery. For example, gastric bypass surgery resolved diabetes in 84% of patients and gastric banding procedures resolved diabetes in 73%. Talk to members of the Bariatric team about this when you are thinking about surgery.

How quickly does surgery improve Type 2 diabetes?

For some people diabetes disappears almost immediately within days of surgery. For others, blood sugar levels begin to fall soon after surgery, becoming completely normal within a year. Each person is different.

Can weight loss surgery help me if I have pre-diabetes?

In studies, people with a condition called impaired glucose tolerance, which can be part of pre-diabetes, showed improvement after weight loss surgery. Talk to members of the Bariatric team about this when you are thinking about surgery.

Will I have to follow a special diet?

Over the first 6 to 8 weeks after surgery, your diet will gradually increase from liquids to semi solid foods. This helps you heal. Longer term, you need to eat healthy in order to lose weight and maintain a healthy weight. You follow guidelines such as eating at mealtimes only, avoiding sugary foods, drinking enough fluids throughout the day, and avoiding overeating and overfilling your stomach. Visit our Nutrition section.

Will I be able to eat only tiny amounts of food?

The amount you can eat depends on the type of surgery you had. Your stomach is smaller which means you will feel full and satisfied with less food. You will have a lot of education about your diet before and after surgery. You need to follow this diet for the rest of your life.

Will I have to exercise?

Studies show that regular exercise after surgery leads to better weight loss results. In the early months after surgery, walking is a good choice. If you have knee or hip problems, you may want to consider non-weight bearing exercise such as water aerobics. As with eating healthy, regular exercise can help you maintain weight loss results over the long term. Your Bariatric Team will work with you to assess your needs and abilities and help you find the right exercises for you.