Best diet for gastric bypass surgery

To have a successful bariatric surgery, you must be ready to create new eating habits. Dietary changes can increase the chance of successful gastric bypass surgery and lead to lifelong results. In this article, we are going to talk about the gastric bypass diet.

Complete guide to the gastric bypass diet

Gastric bypass surgery is not for everyone. You must have the necessary conditions for surgery and consider the risks and benefits. Eligible individuals are typically more than 100 pounds overweight or have a body mass index (BMI) above 40. Also, if a person’s BMI is between 35 and 40 and his or her health is at risk due to overweight, he or she can have gastric bypass surgery.

You need to make changes to your diet before and after this surgery. The goal of a diet before gastric bypass surgery is to reduce the amount of fat in and around the liver. These changes reduce the risk of complications during surgery. After the operation, your doctor will give you specific dietary instructions in several steps. The goal of a post-op diet is to speed up your recovery process, meet the needs of your smaller stomach, and create healthier eating habits.

gastric bypass surgery

Diet before gastric bypass surgery      

Losing weight before gastric bypass surgery can help reduce the amount of fat in your liver and abdomen. This may allow the surgeon to perform your surgery through laparoscopy instead of open surgery. Laparoscopic surgery is less invasive, simpler, and requires much less recovery time.

Losing weight before bariatric surgery will not only make your surgery easier, it will also help you develop new eating habits that you need to stick to after surgery and for the rest of your life.

Your exact diet and your weight loss goal will be determined by your surgeon. It is best to start your pre-op diet as soon as possible. If you can’t lose enough weight, your surgery may be canceled or postponed for a while, so take your pre-op diet seriously and stick to it.

Guidelines to diet before gastric bypass surgery

Dietary guidelines vary from person to person, but usually include:

  • Eliminate or reduce saturated fats, including high-fat dairy products, fatty meats, and fried foods.
  • Eliminate or reduce foods that are high in carbohydrates, including sugary desserts, pasta, potatoes, white bread, and the like.
  • Eliminate sugary drinks such as fruit juices and soft drinks.
  • Control the amount of food you eat.
  • Avoid overeating.
  • Avoid drinking alcohol and smoking.
  • Do not drink with your meals.
  • Take one multivitamin daily.
  • Take protein supplements such as protein shakes or powder.
weight loss surgery

Diet before gastric bypass surgery mainly contains protein shakes and other high-protein, low-calorie foods that are easy to digest. Protein helps strengthen and protect the body’s muscle tissue. This helps your body burn fat instead of burning muscle to produce energy. Protein also helps keep the body strong, which can speed up the healing process after gastric bypass surgery.

As the date of surgery approaches, you may need to follow a diet that is mostly liquid or even completely liquid. Depending on your weight and overall health, your doctor may allow you to eat some solid foods during this time. These may include fish, cooked grains or boiled eggs.

Before surgery, you may need to talk to your anesthesiologist to get his or her dietary recommendations. It is usually recommended to drink carbohydrate-rich drinks up to two hours before gastric bypass surgery.

Diet after gastric bypass surgery

Diet after gastric bypass surgery usually includes several stages. How long each step lasts and what you can eat and drink is determined by your surgeon or nutritionist. All of the steps in this diet emphasize the importance of controlling the amount of food you eat and help you lose weight. It also prepares you for the changes you need to make in your eating habits for the rest of your life.

Step One: Liquid Diet

The type and volume of food you eat in the first step will make it easier for your body to heal and prevent complications after gastric bypass surgery. For the first few days, you are only allowed to drink fluids. This prevents the stomach from stretching due to food intake and makes it recover faster.

Permissible fluids in the first phase of the diet after gastric bypass surgery include the following:

  • Decaffeinated coffee and tea
  • Fat-free milk
  • Thin soup and broth
  • Unsweetened juice
  • Sugar-free gelatin
  • Sugar-free popsicles
Puree diet

Step 2: Puree diet

So if your doctor determines that you can go through the first step, you will enter the next phase of the diet after gastric bypass surgery. This step includes pureed foods whose consistency and thickness are similar to pudding. Different types of purees can be prepared at home with a food processor, mixer or other devices.

Spicy food can irritate the stomach, so avoid them altogether or use them in very small amounts. Avoid fruits that have a lot of seeds, such as strawberries or kiwis. You should also avoid high-fiber foods, such as broccoli and cauliflower. Instead, choose foods that are well liquefied, such as:


  • Apple
  • Banana
  • Canned fruits
  • Peach
  • Apricot
  • Pears
  • Pineapple
  • Melon
weight loss diet


  • Tomato juice
  • Spinach
  • Carrots
  • Squash
  • Green beans


  • Yogurt
  • Whitefish
  • Cheese
  • Beef
  • Chicken
  • Turkey
  • Scrambled eggs

Baby food, such as Cerelac, can also be a good option. Once you start the second phase of your diet after gastric bypass surgery, it’s important not to drink fluids while eating.

Step 3: Soft diet

You may need to continue the puree diet for a few weeks. Once your doctor determines that you are ready, you can start the use of soft foods that are easily chewed. These include the following:

  • Soft boiled eggs
  • Chopped meat
  • Cooked white fish
  • Canned foods such as peaches or pears

It is important to eat small bites. Control the amount of food you eat and eat small amounts at each meal.

healthy diet

Step 4: Stabilization

The fourth step in a gastric bypass post-op diet involves re-introducing solid foods. This procedure usually begins about two months after surgery. At this stage, you still need to chop or dice your food, because now your stomach is much smaller. Large chunks of food can block the stomach, resulting in pain, nausea, and vomiting. It is also good for you to maintain a new stomach size.

Introduce foods slowly. In this way, you can find out which foods your stomach can tolerate and which foods it can’t. As a result, you can identify and eliminate any foods that cause stomach upset, vomiting, or nausea.

Foods that are difficult to digest should be avoided in the fourth stage of the gastric bypass diet, such as:

  • High-fiber or stringy vegetables such as pea pods
  • Popcorn
  • Corn on the cob
  • Carbonated drinks
  • Tough meat
  • Fried food
  • Spicy foods such as pretzels, seeds, and nuts
  • Dried fruits
  • Types of bread and cookies

About four months after the operation, you may be able to resume normal eating. However, controlling the volume of meals is still important. Make sure your diet consists more of fruits, vegetables, lean protein, and healthy carbohydrates. Avoid unhealthy foods that are high in fat, carbohydrates, and calories. Eating well will help you stay healthy and fit for life.

fitness diet

Overall guidelines for gastric bypass surgery diet

Here are some tips to help you maintain the positive outcome of gastric bypass surgery and have a healthier life:

  • Eat and drink slowly.
  • Always monitor the amount of food you eat. Reduce the volume of meals and increase the number of meals.
  • Listen to your body. If you can’t stand a particular food, like a spicy or fried thing, don’t eat it.
  • Avoid high-fat, high-sugar foods.
  • Enjoy drinks between meals but do not drink during meals.
  • Drink enough water daily to prevent dehydration.
  • When eating, take only a small piece of food at a time and chew each piece thoroughly.
  • Take the vitamins your doctor recommends.

Exercise also helps improve your overall health and maintain the surgery results. However, you need to wait a while for your body to recover. For the first month, light exercises such as swimming and walking are good options. Also, simple yoga exercises, stretching, and deep breathing exercises will make you feel better. Over the next few months, you can slowly begin strength training and cardio.

You can also make some changes to your lifestyle, such as:

  • Walk instead of taking a bus or subway.
  • Park your car in a place away from your destination so you can walk a distance.
  • Take the stairs instead of elevators.
  • And many others.
    Leave a comment
    only loggedIn user can send comment! please login or sign up to continue.

    MedGo Personal Quote

    logo Created with Sketch.

    MedGo Team

    • Get a personalized quote for free
    • Free specialist assessment
    • Priority access to appointments