gastric bypass dietGastric Bypass Diet

When people are considering gastric bypass surgery, one thing they are often very curious about is the gastric bypass diet. What will they be able to eat before surgery? What can they eat after surgery? 

This can be a source of stress and anxiety, but it doesn’t have to be. Education beforehand is key to making this transition in your life as seamless as possible. 

To change your eating habits, you will talk extensively with your doctor — Dr. Jay Long — and possibly a dietician as well to come up with the right plan for you, before and after surgery. Remember that following this plan will help you lose weight safely. 

Pre-op gastric surgery diet

We will help you make a plan for a special diet you will need to follow before surgery. This pre-op diet is geared toward reducing the amount of fat in and around your liver to reduce the risk of complications during the surgery. 

Reducing this fat in and around your liver and abdomen may allow you to have a laparoscopic rather than open surgery, which is always our preference at Birmingham Minimally Invasive. This option is less invasive and requires much less recovery time. Overall, it’s easier on your body, so following this pre-op diet so that you can have laparoscopic surgery, if possible, is important.

Starting to make changes in your diet before surgery will also help you start getting used to a new way of eating. This is a lifelong change, so the sooner you start, the better. Your eating plan may begin as soon as you are cleared for the procedure.

Guidelines are individualized for each patient, but may include:

  • Eliminating or decreasing saturated fats, such as whole milk products, fatty meat, and fried food
  • Eliminating or decreasing foods that are high in carbohydrates, such as sugary desserts, pasta, potatoes, and bread
  • Eliminating high-sugar beverages, such as juice and sodas
  • Practicing portion control
  • Avoiding binge eating
  • Quitting smoking
  • Avoiding alcoholic beverages and recreational drugs
  • Not drinking beverages with meals
  • Taking a daily multivitamin
  • Taking protein supplements

With your pre-op diet, you will likely be drinking protein shakes and eating other high-protein, low-calorie foods that are easy to digest. As you get closer to your surgery date, you may need to follow a mostly liquid or liquid-only diet. Based on your weight and overall health, you may be able to eat some solids during this time, such as fish, watered-down hot cereal, or soft-boiled eggs.

Post-op gastric bypass diet

After your surgery, we will tailor a post-op diet specifically for you. It will consist of several weekly phases to help you recover, meet the needs of your smaller stomach, and get used to healthier eating habits.

The post-op gastric bypass diet is designed to:

  • Allow your stomach to heal without being stretched by the food you eat
  • Get you used to eat smaller amounts of food that your smaller stomach can comfortably and safely digest
  • Help you lose weight and avoid gaining weight
  • Avoid side effects and complications from the surgery

A gastric bypass post-op diet typically follows a staged approach to help you ease back into eating solid foods. How quickly you move from one step to the next depends on how fast your body heals and adjusts to the change in eating patterns. You can usually start eating regular foods about three months after surgery.

With each stage it will be important that you do the following:

  • Drink 64 ounces of fluid a day to avoid dehydration
  • Sip liquids between meals, not with meals (This means waiting about 30 minutes after a meal to drink anything and avoiding drinking 30 minutes before a meal.)
  • Eat and drink slowly to avoid dumping syndrome (This occurs when foods and liquids enter your small intestine rapidly and in larger amounts than normal, causing nausea, vomiting, dizziness, sweating, and diarrhea.)
  • Eat lean, protein-rich foods daily
  • Choose foods and drinks that are low in fats and sugar
  • Avoid alcohol
  • Limit caffeine, which can cause dehydration
  • Take vitamin and mineral supplements daily
  • Chew thoroughly to a pureed consistency before swallowing

Stage 1 — Liquids

For the first day or two after surgery, you’ll only be allowed to drink clear liquids. Once you’re handling clear liquids, you can start having other liquids, such as broth; unsweetened juice; decaffeinated tea or coffee; milk (skim or 1 percent); and sugar-free gelatin or popsicles.

Stage 2 — Pureed foods

After about a week and if you are tolerating liquids well, you will begin eating strained and pureed foods. You will be able to eat three to six small meals a day, and each one will consist of four to six tablespoons of food. It should take you about 30 minutes to eat each meal. 

It will be important to choose foods that will puree well, such as lean ground meat, poultry, or fish; cottage cheese; soft scrambled eggs; cooked cereal; soft fruits and cooked vegetables; and strained cream soups. You may need to blend solid foods with a liquid like water, skim milk, no sugar added juice, or broth. 

Stage 3 — Soft foods

We will be keeping up with you during this entire process, and if your progress has been good, you will be able to add soft foods to your diet. Soft foods should be small, tender, and easy to chew. You will be able to have three to five small meals a day, and each meal should consist of one-third to one-half cup of food.

Soft foods include ground lean meat or poultry; flaked fish; eggs; cottage cheese; cooked or dried cereal; rice; canned or soft fresh fruit, without seeds or skin; cooked vegetables, without skin.

Stage 4 — Solid foods

The previous three steps take around eight weeks. If things are going well, at this time you will be able to gradually return to eating more solid foods. We often recommend starting with three meals a day and having each meal consist of 1 to 1.5 cups of food. It’s important to stop eating before you feel completely full.

It’s a good idea to add new foods back one at a time. Certain foods may cause pain, nausea, or vomiting after gastric bypass surgery. Foods that can cause problems at this stage include bread; carbonated drinks; raw vegetables; cooked fibrous vegetables; tough meats; red meat; fried foods; high seasoned or spicy foods; nuts and seeds; and popcorn. Over time, you may be able to try some of these foods again with the guidance of your doctor.

Stage 5 — Your new healthy diet

The gastric bypass diet can help you recover from surgery and transition to a way of eating that is healthy and supports your weight-loss goals. When you get to this point, you have been through a lot. But you will have learned a lot. By this time, most patients are very motivated to keep up the healthy habits they have learned, and we are confident that you will be too. 

Contact Us to Learn More About Gastric Bypass Surgery

Birmingham Minimally Invasive Surgery is a caring group of professionals who specialize in all types of bariatric surgery.  Our surgeon Dr. Jay Long has highly specialized training in bariatric surgery, having completed a fellowship in minimally invasive and bariatric surgery at The Methodist Hospital in Houston, Texas, where he focused on taking care of patients that are morbidly obese.  And we are so proud of our pricing that we publish the costs right on the front page of our website!  Insurance won’t pay?  We have a variety of financing options we can offer you so that you are able to get the healthy body you’ve wanted for years.  Visit us today at or give us a call to set up a consultation at 205-833-6907.