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Your Guide To A Creating A Nutritious Gastric Bypass Diet Menu

Your Guide To A Creating A Nutritious Gastric Bypass Diet Menu

Your diet before and after gastric bypass surgery will be one of the most critical aspects of your recovery from surgery. Indeed, what you eat and how much you eat will also determine how much weight you will lose after gastric bypass. People choose to undergo gastric bypass surgery for several reasons: extreme weight loss, treatment of obesity-related diseases like type 2 diabetes, improved quality of life, and feeling better overall. A nutritious gastric bypass diet menu plan is the cornerstone of your success in achieving your weight loss goals.

Why Do I Need a Gastric Bypass Diet Menu?

Gastric bypass surgery helps people lose 60-80% of their excess weight and is a long-term solution to keeping weight off. Gastric bypass surgery helps people lose weight by limiting the amount of food you can eat, increasing your energy expenditure, and changing gut hormones to reduce your appetite and make you feel full more quickly.

Adhering to a gastric bypass diet menu is crucial if you want to ward off complications from surgery and maintain weight loss. Overeating at once or eating the wrong foods can cause several complications and unpleasant symptoms from the stomach stretching, including:

  • Dumping syndrome
  • Nausea and vomiting
  • Stomach pain
  • Gas
  • Diarrhea
  • Dizziness
  • Acid reflux (or GERD)
  • Obstruction
Following a gastric bypass diet menu can help ward off unpleasant symptoms and complications like dumping syndrome, nausea, and intestinal obstruction.

What Nutrients are Essential for my Gastric Bypass Diet Plan Menu?

Protein is the most critical nutrient for your body before and after gastric bypass surgery. You will need at least 65 grams of protein daily. The best sources of protein after gastric bypass include lean meat, canned tuna, and dairy products. After you can start solid foods, it is best to consume all of your protein in food instead of protein shakes and meal supplements.

After gastric bypass, you will have trouble absorbing certain essential nutrients. Indeed, you will need to take specific supplements for the rest of your life, including:

  • A multivitamin with iron
  • Calcium
  • Vitamin D
  • Vitamin B12

Every person is unique in their nutritional needs, and there are specific requirements for maximizing your absorption of each nutrient. For example, people who undergo gastric bypass surgery need at least 1200 mg of calcium daily, but it is best to divide those doses as the body can only absorb about 500 mg at a time.

Calculating your daily intake of calcium and vitamin D is important, but it is critical for people who have undergone gastric bypass surgery.

If you do not eat foods that are high in nutritional content and do not take supplements, you will be at high risk for nutrient deficiencies.

What Should Be on my Pre Gastric Bypass Diet Menu?

Following a liquid diet before surgery is essential because it jumpstarts your weight loss process, shrinks the liver, and helps you prepare for a liquid diet following surgery. Liver shrinking is especially important because it helps your surgeon visualize your organs better and reduces your complications from surgery.

Most bariatric surgeons require that you follow a liquid diet 7-14 days before surgery. You will only be allowed liquids like protein shakes or meal replacement shakes, broth, sugar-free beverages, and vegetable juices.

Drink at least 64 ounces of water daily. To quench hunger and satisfy cravings for sweets, infuse your water with pieces of your favorite fruit.

What Should a Gastric Bypass Post-Op Diet Menu Look Like?

Your gastric bypass diet menu will be determined by how long it has been since your surgery. In the immediate post-op period, you will need to limit your intake to liquids. For example, a standard gastric bypass post-op diet menu immediately following surgery looks like the following:

Post Op Week 1: Clear liquids only (water, fat-free milk, sugar-free jello, broth)

Post Op Weeks 2 and 3: Protein shakes and pureed foods (Egg whites, soft cheeses, cottage cheese)

Post Op Weeks 4 and 5: Soft foods with an emphasis on lean proteins (lean turkey, chicken, fish, steamed carrots, avocados, bananas, and cucumbers)

Post Op Week 6 and beyond: Solid foods

It is essential to stay hydrated during the post-op phase. Most people require at least 64 fluid ounces of water daily. Drink plain water or add natural flavoring to your water by infusing water with different fruits. Be careful not to drink at the same time as you eat to avoid stretching your stomach.

Meal planning is beneficial, especially once you reach the stage of solid foods. Following a gastric bypass surgery diet menu will ensure that you get all of your essential nutrients while avoiding unhealthy foods.

In general, it helps to have the following servings per day:

  • 3 servings of meat or a meat alternative that is high in protein
  • 3 servings of milk or dairy products
  • 3 servings of starch (rice and bread are best avoided)
  • 2 servings of vegetables (well-cooked is best in the first months after surgery)
  • 1 serving of fruit (avoid the skins and dried fruit for several months after surgery)
Eating nutritionally-dense foods can ward off nutrient deficiencies that can occur with gastric bypass surgery.

2-Day Gastric Bypass Diet Menu Sample

Day 1


Egg whites on avocado slices (eventually you may add one slice of whole wheat bread)

A.M. Snack



Canned tuna with cottage cheese and crackers

P.M. Snack

Sliced apples


Ground turkey patty with steamed vegetables

Post-Dinner Snack (only if you are feeling hungry)

Chopped melons

Day 2


Oatmeal topped with fresh fruit

A.M. Snack

Low-fat string cheese


Low-fat chicken noodle soup with saltine crackers

P.M. Snack

Small can vegetable juice


Grilled chicken breast with mashed sweet potatoes and

Post-Dinner Snack (Only if you are feeling hungry)

1/2 cup skim milk

What Foods Should Be Avoided?

Certain foods will likely aggravate your stomach and increase your chances of dumping syndrome. It is best to avoid these foods, especially in the first few months after surgery:

  • Beans
  • Nuts
  • Whole grains
  • Corn
  • Grapes
  • Beef and pork
  • Shellfish
  • Whole milk
  • Greasy or spicy foods
Meal planning is the cornerstone to achieving your weight loss goals and reducing gastric bypass surgery complications.

Additional Tips for Success

  • Don’t use straws to drink liquids or protein shakes as they can introduce unwanted air into your stomach.
  • Introduce one new food at a time, especially when you can start solid foods. This will help you determine if you can tolerate a portion of food or not.
  • Eat slowly and chew your food thoroughly.
  • Put your protein first so that you ensure you meet your daily protein needs if you feel full quickly.
  • Avoid drinking liquids with meals, especially right after surgery. Liquids that have no caloric value take up valuable space for essential nutrients in your gut.
  • Liquid or chewable supplements are gentler on your stomach following surgery
  • Take calcium supplements at least two hours apart from other supplements, especially those containing iron as calcium and iron block the other’s absorption.
  • Foods that are quite hot or cold can sometimes agitate your stomach and speed up digestion, resulting in dumping syndrome symptoms.
  • Limit eating out as it is hard to control the ingredients and cooking methods that are used for making your meal.
  • Your doctor will likely give you the all-clear to start mild to moderate exercise when you begin protein shakes and puree foods. However, your surgeon will likely advise that you should not lift more than 10 lbs for 6 weeks following surgery.

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Julia Rae Walker, RN, BSN, BA


Julia is an experienced critical care nurse with a background in pediatric and adult patient populations. Her passion is helping patients maximize their quality of life.

Gintas Antanavicius, MD, FACS, FASMBS

Medical Reviewer

Dr. G is a co-founder of BariBuilder. A US-based expert surgeon with over 10 years of bariatric experience, he regularly publishes research in medical journals like SOARD, Obesity Surgery, etc.