Pre & Post Diet

Pre-Op Diet


All patients are required to start a liquid diet 1-2 weeks before their surgery date. Following this diet will jump-start weight loss and help reduce the fat around your liver and spleen, making the procedure easier to perform and thus more successful. A large liver prevents your surgeon from visualizing certain anatomy during the operation, making it unsafe to perform your gastric surgery. Patients must adhere to the diet; otherwise, there is a strong possibility that the surgery may be delayed or canceled during the procedure.

In short, pre-op operative weight loss is desirable to decrease the risk of complications and help the patient and surgeon during the operation and recovery. To be specific, the liquid pre-op diet:

  • Reduces liver size and intra-abdominal fat.
  • Better visibility around the surgical area.
  • Reduces co-morbidities.
  • Increases patient’s understanding of post-op requirements.
  • Reduces operating time.
  • Reduces recovery time.
  • Reduces postoperative risks.

During this time, it is essential to include a protein shake multiple times daily to help ensure good nutritional status before surgery. Aim for a goal of ~ 60-80 grams of protein per day obtained from your protein shake. It would also be beneficial to add a general multivitamin and calcium supplement as a safety net in meeting basic nutrient needs. While swallow form of supplements will be acceptable long-term, initially chewable forms are recommended for optimal digestion and absorption.

The sooner you start healthier eating habits, the easier your transition will be after your surgery. In the months prior to your surgery, it is recommended to get into the habit of eating healthy foods. Since your stomach will not accommodate as much food after the procedure, you must provide your body the nutrients it needs while consuming smaller portions.

During this time, patients should strive to:

  • Eat More Protein: Protein will help you feel full more quickly and help preserve muscle once you begin losing weight.
  • Take Multivitamins: Multivitamins complement your regular diet and should become part of your routine.
  • Avoid Alcohol: After surgery, changes to the digestive tract can cause patients to become intoxicated more quickly. Alcohol contains empty calories, and consumption can also affect willpower and lead to unhealthy eating patterns.

Examples of various liquids that can be consumed during this one to two-week time period include:

  • Clear Broths
  • Meal Replacement Shakes
  • Protein Shakes
  • Sugar-free Beverages
  • Vegetable Juices

Caffeinated and carbonated drinks are strictly forbidden, and patients should wait at least 30 minutes between meals and the consumption of liquids. Adhering to a strict diet plan not only supports a successful surgery but will also help patients learn healthy eating habits to complement their postoperative lifestyles.

Liquid Diet

Generally speaking, the amount of time that people are requested to be on a liquid diet before surgery depends on certain factors, with the patient’s Body Mass Index (BMI) being the main factor.

Body Mass Index
35 or less, liquid diet for 3-5 days
35 to 42 liquid diet for one week
42 to 45 liquid diet for 10 days

BMI of 45 Or More

We rely on the patient’s weight in pounds, for example:

A patient weighing 300 lbs will require 2 weeks, a 400 lbs diet for 3 weeks and so on. Patients are required not to eat or drink anything unless specified by your doctor or preadmission testing on the day of surgery.

Post-Op Diet

The way to succeed

To succeed in the weight loss process and maintain your perfect weight, you will have to permanently change your nutritional lifestyle. Bariatric surgery aims to help you improve your eating habits to promote a healthy loss of weight and its maintenance.

Following surgery, your body will give you signals to stop eating before taking in extra calories that would become excess body weight. It’s what you do with these signals that counts. When you take on new habits and truly stick to them, you can achieve lasting weight loss without experiencing dangerous weight loss/weight gain cycles.

The changes made to your gastrointestinal tract will require lifelong changes in your eating habits that must be followed for successful weight loss. Just like the pre-surgery diet, post-surgery dietary guidelines will vary by bariatric surgeon. You may hear about post-surgery guidelines different from the ones you receive. It is important to remember that these guidelines will differ depending on the surgeon and type of procedure. What is most important is that you follow your surgeon’s instructions.