Gastric Bypass Surgery is something many, unfortunately, have to consider in an effort to better their health.  I have shared about my own journey many times in the past and felt it would be beneficial to have a full guide to start. Anyone considering a weight loss surgery of any type should take the time to go over these tips and thoughts in detail before making the decision. 

Guide to Gastric Bypass Surgery

Gastric bypass surgery is one of the most difficult health decisions you can make.  While it isn’t ideal for everyone, it is a very successful way to lose large amounts of weight and to gain better control over your health. If you have made the hard decision to have this surgery, then this guide will be a helpful resource in the months to come. 

*I use affiliate links in this post. If you buy anything from my links I will earn a small commission*

Bariatric Surgery is not a Quick Fix

This, unfortunately, needs to be repeated.  Lapband, gastric bypass, gastric sleeve, no matter what procedure or name it falls under, bariatric surgery for weight loss is not a quick fix.  It requires dedication, hard work, and potential health struggles long term.  The results, however, for most people are well worth the difficulty.  

Before you begin, you will want to start with my laparoscopic sleeve gastronomy post that gives many of the details to be aware of with your upcoming surgery. If you are sure how this all fits together, you should also ready about how gastric bypass works to further inform yourself on the details of the process.  

If you still think it is an easy out for weight loss, read about the painful truth of gastric bypass.  

Things you will be required to do before having surgery: 

  • Extensive therapy and counselling to determine why food is an issue. 
  • Maintain a diet plan and lose a set amount of weight within a short amount of time. 
  • Visit with a dietician or nutritional coach to learn about how to manage your food intake post-surgery. 
  • Go through many pre-requisites set out by insurance companies and healthcare programs. 

Also, check out my bariatric surgery checklist for those last few things that you may have forgotten to do. 

a guide to gastric bypass surgery

Do I Have to Change My Diet Before Bariatric Surgery? 

In a nutshell, yes, you will need to make dietary changes before you actually have surgery.  Surgeons typically require their patients to lose a set amount of weight over 30-90 days time prior to the surgery date.  This is to make sure you are truly committed to making the surgery a success.  

Additionally, for 10-14 days prior to your surgery date, you will be on a liquid diet or a liver cleansing diet.  This is to prepare your body for the surgery and to help make your liver smaller.  A smaller liver will make the actual procedure easier and safer to perform.  So, no, you will not be able to have a “last meal” the night before surgery to indulge.  Plan to begin your new eating style in advance of the actual surgical procedure. 

For more information on the liver diet, you can check the NHS pre-surgery dietary requirements.  I wrote about the liver shrinking diet as well from my own perspective to help others understand how it works. 

do i have to change my diet before gastric bypass surgery : image of a woman cooking over a cooker

What Can’t I Eat After Gastric Bypass Surgery? 

There are some foods you will need to stop eating after you have surgery.   Many of these foods are things that are harder for your body to break down or can cause reflux more readily.  As you have so much smaller an area for food, reflux and vomiting can be a struggle after surgery.  Avoiding those trigger foods is vital to making sure you are comfortable and progressing.  

When you eat foods from the list of top foods to avoid after gastric bypass, you are putting your life in danger.  An individual who has had weight loss surgery is susceptible to dehydration much faster.  Any foods that cause stomach upset and vomiting put you at risk for not just a little discomfort, but extreme health struggles.  This can also lead to things like dumping syndrome which is not just uncomfortable but potentially dangerous. 

What Can I Eat After Weight Loss Surgery? 

The first few weeks after surgery, you will be eating a mostly liquid diet with a few soft foods thrown in.  I have detailed What to Eat After Gastric Bypass Surgery for your reference.  The information I shared was what I was told prior to surgery by my set of physicians.  It is very important to make sure you follow your doctor’s recommendations.  These may be slightly different depending upon the exact type of surgery you are having and any specific existing health issues. 

For instance, while the post-surgery diet consists of mostly low-carb, low-sugar, and low-fat foods, there are times when someone who is diabetic will be monitored more closely an allowed a bit more of one of these items while medication and insulin levels are being adjusted. 

Follow your doctor’s recommendations above all.  While I have the experience, as do others in support groups, we are not the ones handling your care.  

You will begin with a lot of liquids and soft foods, then transition to more meals.  Protein shakes, broth, gelatin, pudding, and mashed potatoes are common in the early days post-surgery, but you will also be adding a lot of supplements and medications to your routine. It will be some time before you move up to “real food” in your personal menu. 

My Tips for Post Surgery Food Choices

I wrote about the pureed food diet from my surgery experience to help others learn more about how to puree vegetables for post surgery, and the best high protein foods after gastric bypass

Once the regular food stage begins, you will be focused on foods with protein that are easy to digest.  Eggs, tofu, lean ground meat, cottage cheese, and soft vegetables are most common.  You can use my tips for low carb diet after gastric bypass to get through this period of time in your journey.  

One thing you will be told to have a lot of is water.  Your diet will be expected to contain a large volume of water to avoid dehydration as your meals will be smaller and you will be ingesting less fluid in your meals than your boy is used to having. 

You may also want to check out my tips for the soft food diet post weight loss surgery

gastric bypass and bariatric surgery post food choices

What are the Portion Sizes After Bariatric Surgery? 

One of the most difficult things post-surgery is adjusting to the tiny portion sizes.  Only 2-4 teaspoons at a meal will be allowed.  That is why prior to surgery you will have a lot of reminders to “sip” fluids.  You no longer will be able to drink a glass of water. Instead, you will take in small sips throughout the day. 

The same will happen with your foods.  You want to pack the most nutrients into the smallest packages.  That is why 2-3 teaspoons of ground chicken and a teaspoon of pureed carrots may be all you have at one meal.  It has nutrients you need and is small enough to not cause issues.  I found that preparing these small portions ahead of time was necessary.  In fact, I wrote about why meal prepping is so important for weight loss

There is a lot of information on the Mayo Clinic Bariatric Surgery guide for you to learn about portions, foods you can eat, and how to cope after surgery. 

portion sizes after gastric bypass surgery

Will I Ever Be Able to Change My Menu? 

Yes and no.  At some point down the road, you can begin eating more or different foods, but for optimum success, you will truly have to stick with this diet plan for the rest of your life. 

Will you one day be able to eat a piece of chocolate during the holidays?  Yes, but you will also need to be careful about how much, with what, and how fast you eat it and other trigger foods. The goal of this surgery is to change the way you think about food and how you use it.  Sure, you may want to have a hamburger again, but gone are the days where that is really a possibility for your menu. 

I hope you found this post super useful! Please do take the time to Pin this content so others can benefit from this information! 

a guide to gastric bypass surgery

Have You Read The Ultimate Guide To Gastric Bypass Surgery?

About Angela Milnes

Angela Milnes is a qualified teacher, blogger and recipe developer. She has experience teaching cooking and life skills to different age groups and is a bariatric patient offering support those looking to lose weight and live a healthier lifestyle. Find Days In Bed Bariatric Life On Facebook!