Bariatric Surgery Diet – How to prepare your new life

Bariatric surgery, also known as weight-loss surgery, is performed on people who are obese or who, despite their best efforts, struggle to lose weight. The surgery is often followed by a special bariatric surgery diet, intended to give the gastrointestinal tract some time to recover.

Without a doubt, the surgery will affect your entire life, in a good way–but you have to make sure you follow all necessary guidelines before and after the surgery. You should expect to make some significant changes in your lifestyle to ensure that your bariatric surgery is successful in the long run. 

General Guidelines

Before undergoing surgery, some weight loss is crucial to ensure lifelong success. Your doctor will likely put you on a pre-op bariatric diet to reduce your liver’s weight and size, minimize post-op complications, and encourage faster healing of your body. It’s also a way to train your body for the post-surgery diet. 

During this time, some general tips include:

  • Avoid smoking
  • Reduce or eliminate your alcohol intake
  • Practice portion control
  • Avoid binge eating
  • Stop taking over-the-counter medications such as aspirin, ibuprofen (i.e., Advil), and steroids.

Bariatric Surgery Diet: Fluids, protein, and supplements

Odds are that before your surgery, your doctor or registered dietitian will prescribe a bariatric surgery diet that increases fluid and protein intake while decreasing simple carbohydrates. 

Before the bariatric surgery can take place, increased fluid intake is required. It is part of the perioperative fluid management process, regulating proper hydration, electrolyte balance, and post-op fluid loss. 

With surgery about 1-2 weeks away, your doctor will start you on a specific liquid diet. The diet will depend on your surgeon’s recommendation. 

Fluids should be sipped slowly (without a straw), and all liquid calories must be avoided.

Meal Replacement Shakes

Drink 5 shakes per day from the following list:

  • Bariatric Advantage® High Protein Meal Replacement 
  • Celebrate® High Protein Meal Replacement
  • Premier Protein® Shake
  • Atkins® Shakes (Blue or red top; the only difference is size-11 or 16.9 ounces, respectively.)
  • Ensure® Max Protein (NOT regular Ensure)


Drink at least 8 cups per day of sugar-free beverages (10 calories or less per serving) This could include:

  • Water
  • Sugar Free powdered drink mix
  • Crystal Light™
  • Zero Sugar Kool-Aid®
  • Propel® 
  • POWERADE Zero Sugar®
  • G Zero® by Gatorade
  • Diet juice (NOT “No Sugar Added”)
  • Coffee
  • Unsweetened tea

Other products

Enjoy these in unlimited quantity:

  • JELL-O™ Sugar-free products
  • Sugar-free popsicles
  • Broth (Regular or low-sodium)
  • **All artificial sweeteners are acceptable

Before the surgery, you’ll have to increase your lean protein intake to help your recovery following the surgery. More lean protein helps preserve muscle mass, which in turn helps with weight loss. 

Good protein sources include lean chicken, lean beef, eggs, flaky white fish, cheese, low-carb yogurt, tofu, and beans.

Protein shakes and supplements are other additional sources you can rely on, though quality always wins over quantity! 

Vitamin supplementation

As for vitamin supplements, before surgery, you’ll need to initiate a regimen to overcome any nutritional deficit. Being overweight and consuming foods that are dense in calories can result in vitamin deficiencies and impaired absorption. This can create chronic inflammation and affect the way vitamins and minerals are processed by the body.

Chronic inflammation can affect iron metabolism. Other vitamin deficiencies include folic acid and vitamins D, B1, and B12. Why does this matter? Impaired vitamin absorption can lead to post-op malnutrition. 

All of this can sound overwhelming, but it’s actually quite simple; you take a multivitamin as part of your pre-op preparation.

Your doctor will outline the exact guidelines for your bariatric surgery diet, vitamin supplements, and fluid intake. These parameters are based on your body’s needs. Every person differs in their nutritional requirements, and a personalized diet plan is essential to ensure good outcomes.

Diet progression after bariatric surgery

After the surgery, you’ll continue with your bariatric surgery diet under the guidance of your doctor and dietitian. The phases of your post-op diet are:

0-14 Days Post-op:

This initial post-op phase consists of a liquid diet. Every surgeon has their preferred recommendations. The objective is to maintain hydration and provide nutrition. Most programs will involve consuming protein shakes and liquids that contain neither calories nor sugar.

2-6 Weeks:

Your diet plan will progress to soft foods. Examples of these include:                         

  • Chicken salad
  • Tuna salad
  • Egg salad
  • Eggs any style
  • Cold cuts
  • Flaky white fish (non-breaded)
  • Soft cooked beans
  • Cheese
  • Tofu
  • Light yogurt

It is essential that each serving contain 10 grams or less of total carbs.

6 Weeks-6 Months:

At the one-month mark, depending on your healing process, you can progress to eating solids foods:

  • Non-Breaded beef
  • Chicken
  • Pork
  • Turkey
  • Seafood
  • Eggs
  • Venison
  • Lamb
  • Tofu
  • Cheese
  • Light yogurt

Again, the key is to ensure that each serving contain 10 grams of total carbs or less.

6 Months-1 Year:

At six months post-op, you can begin introducing carbohydrates in small amounts.

In closing…

Your success in maintaining weight loss depends on your willingness and determination to modify your existing eating patterns, develop healthy habits, and learn new eating behaviors. The bariatric surgery diet begins before the procedure and continues in the months following the surgery. Committing to your post-op diet is worth the effort to achieve positive long-term outcomes.

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