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Pre-Op Liquid Diet

The preoperative liquid diet, also known as the liver reduction diet, is an important part of the safety and effectiveness of your bariatric procedure. All patients will be placed on this two-week diet immediately before their surgical procedure. The purpose of the liquid diet is to shrink the liver and allow patient to lose some excess body fat. Doing so improves laparoscopic access to the abdomen and makes the procedure generally safer.

Secondarily, the pre-op liquid diet helps prepare patients for the dietary restrictions they will experience immediately after surgery. Patients will be on a liquid diet for up to 4 weeks after surgery, and although the liquid diet after surgery will be different from the pre-surgical diet, knowing what to expect beforehand can make for a much easier and more successful transition.

The liquid diet is relatively simple, with patients allowed to consume meal replacement drinks as well clear liquids like water and broth (listed below). Patients will consume approximately 1200 calories a day, which should come mostly from these meal replacement drinks. The goal is to offer complete nutritional balance while avoiding high-fat and high-sugar products.

Protein is a foundational part of the pre-and post-surgical diet, offering patients a greater sense of fullness while keeping sugar spikes under control. Therefore, patients will need to consume up to 80 g of protein each day. Since this is almost impossible on a liquid diet without supplementation, we recommend protein shakes 3-5 times per day. There are many protein shakes on the market, but some have significant amounts of sugar, which is counterproductive to the post-surgery program. We encourage you to follow the list of recommended protein shakes that we will provide to you before surgery, many of which are specifically designed for bariatric surgery patients.

During this period, all patients will also have to supplement their diets to avoid any nutritional deficiencies. Supplements will include a multivitamin as well as a combination calcium-and-vitamin D supplement. Other supplements will be recommended as needed, based on pre-op testing and bloodwork. Once again, there are several supplement companies that have formulated their products specifically for bariatric surgery patients, and we will guide you toward those choices.

Below, you will find some of the liquids that are acceptable for consumption for the pre-op diet phase. The liquids below are to be consumed between meal replacement shakes to keep patients hydrated and promote satiety:

Clear Liquids Examples

  • Water (Infused, flavored, Crystal Light is OK)
  • Broths (low sodium)
  • Low sugar athletic drinks (Gatorade, Powerade, etc.)
  • Unsweetened tea and coffee (decaf)
  • Low sugar gelatin (Jell-O, etc.)
Our Surgical Weight Loss Program and Bariatric Surgery Center's mission is to deliver safe and effective surgical solutions with a compassionate touch. Our bariatric program is operated by NYU Langone Long Island Surgical Associates, P.C., a network of leading physicians and surgeons that provide comprehensive care for patients.

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