Gastric Bypass Diet

The Gastric Bypass Diet: What to Eat Before and After Gastric Bypass Surgery

Having Gastric Bypass surgery can seem like a lifeline for those struggling with severe obesity. But while procedures like the gastric bypass help limit food intake, patients must make dramatic dietary changes for the surgery to work long-term. Here’s a complete guide to the gastric bypass diet.

Gastric Bypass Surgery Graphic


What is the Gastric Bypass Diet?

The gastric bypass diet progresses through several stages:

  • Pre-op diet: For 2 weeks before surgery, you follow a very low-calorie liquid diet to shrink your liver to give surgeons better access to your stomach.
  • Stage 1 diet: Starts the day after surgery. Liquids only, drinking 1-2 oz per hour to avoid stretching your tiny new stomach pouch.
  • Stage 2 diet: Begins 2 weeks after surgery. Pureed high protein foods like yogurt, cottage cheese, refried beans.
  • Stage 3 diet: Starts 2 months after surgery. Soft, easy to chew foods like eggs, fish, chicken.
  • Lifelong diet: Low fat, low sugar, high protein, small frequent meals. Followed forever to maintain weight loss! 

Continue Reading... Bariatric Foods: What Foods Are In A Bariatric Diet?


Gastric Bypass Diet By Stage

Below are the foods you can eat at each stage of recovery:

Pre-Op Liver Shrinking Diet

  • Protein shakes
  • Nonfat milk and yogurt
  • Egg whites
  • Broth-based soups
  • Sugar-free gelatin and popsicles

Stage 1: Liquids Only

  • Water
  • Low-calorie protein shakes
  • Skim or soy milk
  • Sugar-free drinks

Stage 2: Pureed Foods

  • No sugar added applesauce
  • Pureed soups
  • Unsweetened puddings
  • Low-fat refried beans
  • Pureed soft tofu

Stage 3: Soft Foods

  • Soft, flaky fish
  • Ground chicken or turkey
  • Cooked veggies like spinach, carrots
  • Creamy peanut butter
  • Cottage cheese
  • Cooked pasta

Stage 4: Long-Term Gastric Bypass Diet

Around 3-6 months after surgery, you can slowly add in a wider variety of foods. But you must follow a high protein, low sugar, low fat diet for life. Here’s what a typical day may include:


Meal Food Items
Breakfast 1 scrambled egg
1⁄2 cup lowfat cottage cheese
Small slice whole grain toast
Morning Snack 1⁄2 scoop protein powder blended with water
Lunch 2 oz grilled chicken
Small baked sweet potato
Steamed veggies
Afternoon Snack Lowfat string cheese stick
10 almonds
Dinner 3 oz salmon
1⁄2 cup brown rice
Side salad with lowfat dressing
Evening Snack Sugar-free pudding cup
Herbal tea


Foods to Avoid With Gastric Bypass

Avoid high fat, high sugar foods which can cause dumping syndrome:

✖️ Fried foods ✖️ Full fat dairy ✖️ Fatty meats like bacon or sausage
✖️ Pizza, burgers, hot dogs ✖️ Cookies, cake, candy, ice cream ✖️ Juice, soda

Stick to a high protein gastric bypass diet with at least 60g protein daily from:

✅ Fish ✅ Poultry
✅ Egg whites ✅ Lowfat dairy ✅ Beans, lentils
✅ Protein powder

Supplement Guidelines After Gastric Bypass Surgery

Bariatric One A Day Multivitamins

Daily vitamins are crucial since food intake is drastically reduced:

Meeting with a dietitian helps customize your supplements. Bloodwork checks for deficiencies.

Making the Gastric Bypass Diet a Lifelong Success

Getting used to small frequent meals takes time. But following these tips ensures you safely lose excess weight and keep it off long-term:

  • Eat only until satisfied, not full
  • Go slow, chew thoroughly
  • Get 70-100g protein daily
  • Make a list of go-to bariatric protein shakes and protein bars
  • Take vitamins and supplements
  • Find new healthy recipes
  • Join a bariatric support community
  • Keep food records to stay accountable
  • Exercise daily as cleared by your surgeon

The gastric bypass diet requires dedication, but it leads to incredible health rewards that make it all worthwhile!




Writer: Allison


Allison is a seasoned nutritionist and writer with over 15 years in health and weight management. She's authored journals on medical weight loss and bariatric medicine, and has specialized in bariatric foods.


Reviewed By: Dr. K. Huffman


Dr. Kevin D. Huffman, D.O., is a board-certified bariatric physician renowned for his expertise in treating obesity. With over 10,000 patients and a reputation as a national leader in bariatric medicine, he has trained hundreds of healthcare providers. Dr. Huffman develops protocols and training materials sought after by medical societies, pharmaceutical companies, patients, and hospitals.

Weight Loss & Nutrition Journal

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