Sticking to a healthy post gastric bypass diet is incredibly important to ensuring the success of the surgery. It helps the patient heal, and also changes their eating habits for the better, which ensures a healthy lifestyle and successful transformation for the rest of their lives.

Gastric bypass or bariatric diets allow your stomach to heal naturally and gradually without being stretched by solid or irritating foods. This can lead to complications and dangerous side effects. It also lets your body get used to having smaller portions that your stomach can safely and effectively digest.

Typically, these types of diets are separated into stages that ease you back into a normal diet. Some people recommend about a week for each phase, but the timing in terms of when you move to the next stage depends on your unique circumstances and how quickly you recover. But generally, it takes on average about 3 months for gastric bypass patients to be able to eat regular food again.

For the purposes of this article, we’ll stick with the immediate 2 week (or 2 phase) period post surgery. Of course, you should consult with your doctor, surgeon, and dietician before committing to a specific meal plan, but the suggestions and tips below can help you stick to your diet and remind you of what you need most after this type of surgery.

Phase 1 – Liquids

yellow chicken broth in a white bowl with a spoon
Clear broths like chicken offer nutrients without overfilling you.

Immediately after surgery during phase 1, you should only be consuming clear liquids. It’s incredibly important that you stay well-hydrated during this time Below are some of the most common and safe liquids you can consume:

  • Water
  • Broth (fat free)
  • Skim milk
  • Unsweetened juice
  • Decaffeinated tea
  • Sugar-free jello

Try to drink very slowly, and only have 1 to 3  ounces at a time (or per hour) so that you don’t overwhelm your system. Also stay away from drinking these liquids through straws because it’s likely that they’ll bring air into the stomach, which could irritate the surgery.

Phase 2 – Pureed Foods

When you’re ready to transition out of phase 1 (usually about 2 to 7 days after surgery), you can start having some liquefied, pureed foods. This stage usually lasts another 1 to 2 weeks.

The texture of these foods should be a smooth paste or thick liquid so that it’s still gentle enough on your system to digest properly. There should not be any solid pieces of food in the mixtures yet. The point of this phase is to start introducing some vital nutrients back into your diet, like protein and other vitamins and minerals that come from solid foods.

Below are some typical solid protein sources that doctors recommend for gastric bypass patients, as well as some safe liquids that they can be pureed with to create your meals during this phase.

You can see some pureed food recipes for use after bariatric surgery in this post.

bright green pureed soup in a white bowl with a parsley garnish
Pureed foods like soups are the next step in restoring your diet after bariatric surgery.

Protein sources:

  • Beans
  • Fish
  • Eggs/egg whites
  • Soft fruits and cooked vegetables
  • Nonfat cottage cheese
  • Protein shakes
  • Lean ground meats


  • Water
  • Skim milk
  • Unsweetened juice
  • Broth


In terms of protein intake, you’ll need about 60-70 grams of protein per day. You’ll also need about 64 ounces of clear liquids per day, which doesn’t include the pureed foods.

Clear liquids shouldn’t be consumed in conjunction with pureed foods, as this might overwhelm your system. Try not to drink any clear liquid 30 minutes before a meal, or 60 minutes after a meal to allow your meal adequate space to digest.

Remember that no matter how much you loved them before, your system might not able to process dairy or meat products just yet, as these are very heavy and processed. Your stomach may also be sensitive to spicy foods as well. If any of these foods irritate you in any way, stay away from them during this phase and start to work them in slowly in small portions after phase 2 is complete.


During phase 2, it’s also time to start integrating vitamins and supplements into your diet. Every day you’ll need to take 1 or 2 multivitamins with iron to prevent nutrient deficiency. They should NOT be solid though – look for liquid multivitamins or chewable gummy vitamins.

You should also supplement your diet with about 2 to 3 doses of 400 mg to 600 mg of calcium citrate. This vitamin is typically not included in a multivitamin. Take this at least 2 hours before or after your multivitamin, as the iron may not react well with the calcium citrate.

Foods to Avoid

close up of brown cola with large ice cubes in a clear glassDuring both phases, avoid carbonated beverages and caffeinated beverages, even if they are clear. These elements can be very painful to digest during this time, and may complicate the surgery.

Also stay away from refined sugars and simple carbohydrates like sugar alcohols, as these will not work well with your new system just yet. Even when you can digest these (about 3 months after your surgery) try to integrate them slowly, and then only have them in moderation to ensure that you keep the weight off.

Summary and Sources

Again, your doctor, surgeon, and/or nutritionist will go over your ideal, unique meal plan after your gastric bypass surgery, but if you need a refresher or suggestions, feel free to come back to this guide and follow my tips and instructions. Gastric bypass is a very sensitive surgery that requires a lot of aftercare, so to ensure a safe and successful surgery, make sure to stick to this bariatric diet.

Have you ever followed a diet like this? Please share your experience and options with us. All your advice is appreciated.