Gastric Bypass Guide

What is Gastric Bypass Surgery?

*Treatment results may vary
Gastric bypass is a type of weight loss surgery, which divides the stomach into two pouches, a smaller upper pouch and a larger lower pouch. The lower pouch becomes unused and the upper pouch, which has been reduced by approximately 90% becomes the new stomach. The small intestine is also rearranged to connect to both pouches and the length of intestine available for absorption is reduced to decrease the amount of fats and calories being absorbed from food. Gastric bypass surgery is carried out laparoscopically, which means there are no large incisions or scars.

Gastric bypass is both a malabsorbative and restrictive type of weight loss surgery. This means that it reduces the amount of vitamins, minerals, fats and sugars that your body absorbs while also restricting how much food you can eat, because of the reduced size of your new stomach.

Who can have Gastric Bypass Surgery?

Gastric bypass surgery is usually carried out on patients who have a Body mass Index (BMI) of 40 or more or a BMI of 35 with medical problems related to obesity. This is classed as morbidly obese and in a lot of cases means the patients also have co-morbidities, such as: type 2 diabetes, high blood pressure and sleep apnea. After gastric bypass surgery there is usually a dramatic weight loss, which can also reduce or remove altogether the co-morbidities mentioned above.

Who can perform Gastric Bypass Surgery?

Any doctor who is board certified in general surgery is able to perform gastric bypass surgery. However, you will find that most bariatric surgeons specialize in weight loss surgery. Although not required by law, doctors specializing in weight loss surgery can become accredited by the American Society for Metabolic and Bariatric Surgery (ASMBS). The ASMBS ensures that all doctors are certified by the American Board of Surgery and have performed a minimum of 25 bariatric surgeries in the previous two years.

8 Things to Know When Getting Gastric Bypass Surgery

1. Change Your Eating Habits Before Surgery

*Treatment results may vary
You're making a lifelong commitment to eating better and getting your body in shape. The hard work starts before you even have the procedure. Changing your diet before surgery will make it a lot easier to stick to after surgery. Start swapping out some of your foods for low fat or fat free versions, cut down on the take-out foods and introduce more fruits, vegetables and proteins into your diet.

2. Start Exercising

*Treatment results may vary
Exercise is going to be an important part of your weight loss journey. To begin with, the gastric bypass alone will help you to lose weight, but after a period of time you will need to make sure you do some exercise in order to go forward with weight loss or to maintain your new weight. Just like changing your diet, starting an exercise routine is easier if you start before surgery. If you're not used to exercising at all then start by taking a walk around your neighborhood, slowly you can move up to longer, and more intense walks, joining an exercise class, using the gym or following a work-out DVD. After surgery you will still be able to exercise, but you may need to slow the pace down for the first couple of weeks and return to gentle walks until you're healed from surgery.

3. Know Your Body and Mind

Gastric bypass surgery isn't the answer to all of your problems, it's a tool that will help you lose a drastic amount of weight if you treat it right and follow the rules. The biggest obstacle to losing weight will be your own mind. You need to know what your triggers are, what makes your binge on food, order take-out or drink too much alcohol. For a lot of people feeling down or stressed can trigger this overindulgence and you need to know this before you have surgery so that you can make the right choices after surgery. The gastric bypass won't take these cravings away but it will help you to make the right decisions.

4. Don't Eat Too Soon

*Treatment results may vary
Gastric bypass surgery is going to drastically reduce your stomach and reorganize your intestines. It will be a few weeks before you can start to eat normal foods again and even then you may never be able to eat some of things you could before surgery. It's important you follow your doctors advice and meal plans following surgery, this will most likely start with a clear liquids only diet and will move onto other liquids, soft foods and then normal food. You're going to be teaching your body to eat again, portions will be smaller and your whole diet may change. Take things slow, listen to your doctor and most importantly, listen to your body.

5. Drink a Lot of Water

*Treatment results may vary
It's common knowledge now that the average person should be drinking approximately 2 litres of water per day to stay healthy and hydrated. This is also true after gastric bypass surgery. Your brain, muscles, hair, eyesight and kidneys all rely on water to keep them in good working order. After surgery it is going to be hard to drink enough, especially at first, when you are re-learning to eat. However, it's vitally important that you drink enough. A good tip is to carry a bottle of water with you at all times and just sip, sip, sip through the day.

6. Take Your Vitamins

*Treatment results may vary
Gastric bypass is a malabsorbative surgery, which means it restricts the amount of fats and sugars your body absorbs from food. However, it also restricts the amount of vitamins and minerals that are absorbed, which means you will need to take vitamin supplements for the rest of your life. The type of vitamins you will need to take can vary between individuals, you may only need a one-size-fits-all vitamin or you may need several different types, suited specifically to you. Your doctor will be able to tell you what is best for you. The most important thing is that you take them daily. It doesn't take a lot of effort to take a vitamin pill once per day, however, the effects of vitamin deficiency can be damaging and sometimes life-long. So, in this one instance, take the easy route and take your vitamins pills, you'll be glad you did!

7. Join a Support Group

You can do this before surgery and have the support throughout the whole process, or join a group after surgery to help you through the post-op process. Support is going to be key to a successful gastric bypass journey and getting support from people who are in the same situation as you is very beneficial. Your doctor may know of a local support group or may even have a support group linked to the surgery. If not you can go online to look up your local groups or join on online support group such as The most important things is that you find a group that fits you and that can help you through your harder periods and celebrate with you through the good.

8. Re-evaluate and Don't Give Up

*Treatment results may vary
After you've lived with your new stomach and new lifestyle for a while you can get a little sluggish, maybe stop counting calories as much, increase your portion sizes or begin eating fatty foods and you'll start to see a little weight gain. This doesn't mean your surgery has stopped working or that your pouch is stretched too much, it means that you need to re-evaluate your eating and exercise habits. There's always a reason for weight gain and it's usually something to do with increased food intake or a reduction in exercise. Start writing down everything you eat and drink over a period of one week along with every time you exercise and for how long. You'll then be able to evaluate if what you're actually eating/drinking is in line with what you think you've been eating and drinking. If that doesn't work then t may be time to re-connect with your doctor or dietician to work out a new plan or start going back to some support group meetings. You will be able to turn it around, you did it once and you can do it again!

Eating and Drinking After Gastric Bypass Surgery

*Treatment results may vary
There are a few universal rules for gastric bypass patients, and foods and drinks you must avoid to have post-op success.

After Surgery Do Not:

  • Eat large quantities
  • Drink with your meals
  • Eat or drink quickly
  • Drink with a straw (depending on individual tolerance)

Foods and Drinks to Avoid

  • Alcohol
  • Carbonated beverages
  • High-fat foods
  • High-carbohydrate foods (bread, rice, pasta, etc.)
  • High-sugar foods and drinks

Your doctor and nutritionist will help you develop a plan for your post-op meals. This generally occurs in four stages:

Stage 1 - Clear Liquids

You will gradually be placed on a clear liquid diet while you are recovering in the hospital. You will start with small sips of water, under the supervision of your doctor. Within a few days, you will slowly begin to drink other clear liquids, again in very small amounts.

Your doctor must know that you'll be able to drink normally and without complications. Being able to drink clear liquids is required before being discharged from the hospital.

Stage 2 - Liquid Diet

Once you are home, you will begin a liquid diet that lasts approximately one to two weeks. Start with clear liquids and slowly build up to other types of liquid food:

  • Broths
  • Protein shakes
  • Decaf coffee and tea
  • Low-fat yogurt

Drink small amounts and take breaks between each sip. If you are trying a soup or yogurt, make sure to strain out any whole pieces of food before drinking.

Stage 3 - Soft Foods

For the next month (roughly two to six weeks post-op), your doctor will place you on a soft-foods diet. Just like with the liquid diet, you will start with easier foods (such as broths) and build up your tolerance for more solid foods. For example:

  • Scrambled egg whites
  • Very soft, ground meats (including ground turkey and flaky fish)
  • Cottage cheese
  • Oatmeal, cream of wheat and grits
  • Pureed chunky soups
  • Mushy fruits like applesauce

Stage 4 - Normal Diet

Your doctor or nutritionist will generally advise that you can start eating normal foods approximately six to eight weeks post-op, depending on your progress during the other diet stages.

The term "normal" is relative here. This is your new, lifelong eating plan. Choose foods that are high in protein and low in carbohydrates, sugars and fats. Your smaller stomach will inhibit how much you can eat, so you must take care to eat the healthiest foods that you can. There is no room in your new diet for "empty" calories, such as sweets or junk food.

Luckily (though it may seem unlucky at first!), your new stomach will not be able to tolerate fatty, high-carb or high-sugar foods. Eating these types of foods will lead to a process known as "dumping syndrome."

What is Dumping Syndrome?

Dumping syndrome occurs when too much food is rushed through your stomach and enters your small intestine too quickly. It most commonly occurs with foods that are high in fat, carbohydrates and sugars.

Dumping syndrome leads to drastic feelings of discomfort, including nausea, stomach cramps and diarrhea. You may also suffer from symptoms of low blood surgery due to your body's attempts to compensate: you may feel faint and sweaty, to the point that you need to lie down.

Not all patients experience dumping syndrome, and foods that may trigger dumping in one person may have little or no effect on someone else. But if you do experience dumping, it is usually a warning that you're eating something that is not good for you.

Your Long-Term Success Tools

Gastric bypass surgery itself only lasts for several hours, but it will take you a lifetime to build and continue the healthy eating habits that will ultimately make your surgery a success. Here are some top tips for handling the psychological side of post-op life:

  • Listen to Your Body - As we mentioned earlier, dumping syndrome is an unpleasant feeling, but it is a positive signal from your body that you're eating something you shouldn't. Listen to your body: don't eat things that don't agree with you, eat only when you're hungry, and stop eating when you're full. Your body will tell your brain everything it needs to know.
  • Avoid Temptation - Everybody has different food triggers, so this is a very personal recommendation. Think carefully about what causes you to over-indulge: is it drinks with friends, restaurant meals or lunches at work? Plan ahead for whatever might tempt you and avoid situations (at least initially) that are going to cause you to eat or drink unhealthily.
  • Ask For Help - Your bariatric team, including your surgeon and nutritionist, are there to help. Consider them a lifelong resource and don't be afraid to ask for help if you have questions or concerns.
  • Find a Support Group - Gastric bypass surgery requires making changes to a lifetime of eating habits. But you're not alone! Join an online support group, such as, where you can get advice from other gastric bypass patients any time, day or night. Your bariatric surgeon may also know of in-person support groups in your area where you can meet other post-op patients.
  • Embrace Positivity - Gastric bypass surgery is a major life event that leads to a lifetime of changes. Find the people, resources and inspiration that will support your new diet.

Life after gastric bypass is challenging, but also can be rewarding. By keeping a positive outlook and embracing your new diet and lifestyle, you'll lose weight and transition into a healthy post-op life.

Disclaimer: This content is for educational and informational purposes only. It is not a substitute for medical advice, diagnosis, or treatment provided by a qualified healthcare professional. Your reliance on any information or content provided in the guide is solely at your own risk. You should always seek the advice of your physician or healthcare professional for any questions you have about your own medical condition. RealSelf does not endorse or recommend any specific content, procedure, product, opinion, healthcare professional, or any other material or information in this guide or anywhere on this website.

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