Bariatric surgery stands as the most effective long-term solution for weight loss, reducing comorbidities, and decreasing mortality in individuals with severe obesity. Nutritional management, both before and after surgery, is crucial for optimizing patient outcomes. A key component of the preoperative phase is the clear liquid diet, designed to prepare the body for surgery and initiate the lifestyle changes necessary for sustained success.
Purpose of the Preoperative Clear Liquid Diet
The preoperative clear liquid diet serves several important purposes. It aids in weight loss before surgery, potentially reducing the need to convert a laparoscopic procedure to open surgery. Adherence to the surgeon's instructions is paramount, as noncompliance can lead to surgery cancellation. The diet also helps to shrink the liver, reduce intra-abdominal fat mass, blood loss, short-term complications as well as operation time and length of hospital stay.
What is a Clear Liquid Diet?
A clear liquid diet restricts you to options such as water, broth, and plain gelatin. These are easy to digest and don't leave food bits in your digestive tract. Clear liquids may have some color. Liquids with some color are allowed if you can see through them. Foods can be considered liquid if they partly or completely melt to clear fluid at room temperature. Your healthcare professional may prescribe a clear liquid diet before or after some medical procedures or if you have digestive problems such as vomiting or diarrhea.
Duration and Timing
Typically, the clear liquid diet begins approximately two weeks before surgery, as specified by your physician. Starting two days prior to your operation, you will begin a clear liquid diet and continue throughout the day to prepare your digestive tract for surgery. This diet ensures your stomach and intestines are mostly empty while keeping you hydrated.
Allowed and Restricted Foods
On a clear liquid diet, you can consume:
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- Water
- Clear broth
- Plain gelatin
- Clear fruit juices such as apple juice and white cranberry juice
- Plain tea or black coffee (NO milk or creamer)
- Clear, electrolyte-replenishing drinks such as Pedialyte, Gatorade, or Powerade (NOT yogurt or pulp-containing "smoothies")
- Ensure Clear or Boost Breeze (NOT the milkshake varieties)
- Sugar-free versions of drink mixes like Kool-Aid and Crystal Light
It is important to avoid:
- Solid foods
- Milk and dairy products
- Alcoholic beverages
- Liquids with red or purple coloring
- Regular fruit juice
- Slider foods
Nutritional Considerations
A clear liquid diet can't give you all the calories and nutrients you need. It is designed to be very low in carbohydrates and fat to force your body to use the fat stores it already has. In addition to clear liquids, aim for a fluid intake of 64 ounces per day. Your physician may allow protein drinks such as Nectar and Isopure, but make sure to consume only the recommended amount. The liquid diet is designed to be very low in carbohydrates and fat to force your body to use the fat stores it already has. This helps your body use the fat in your liver and shrinks the liver before surgery. Other than protein supplements, you should only drink calorie-free or low-calorie drinks, such as water, flavored waters, sugar-free gelatin and/or broth.
Managing Discomfort
It is normal to feel nauseous, have a headache, or become irritable during the first 48-72 hours of your liquid diet. These bad feelings will pass as your body gets used to the diet. It is also normal to have loose stools and need to use the restroom frequently during the liquid diet.
Special Considerations
- Diabetes: If you have diabetes, talk with the healthcare professional who helps manage your condition. You may get specific instructions to help manage your blood sugar, also called blood glucose, while on a clear liquid diet. Test your blood glucose levels often.
- Medications: Also, take any medication as directed by Dr. Certain medications must also be discontinued prior to surgery.
- Bowel Prep: Around noon the day prior to your weight loss operation you will be instructed to begin bowel prep.
- Fasting: Do not eat or drink anything, including mints or gum. Do not swallow any water while brushing your teeth and rinsing. It’s normal to feel hungry in the morning when you check into the hospital.
Preoperative Weight Loss: What the Research Says
While some studies suggest that a modest weight loss of 5-10% in the immediate preoperative period could facilitate surgery and reduce the risk of complications, evidences from randomized and retrospective studies do not support the hypothesis that pre-operative weight loss could improve weight loss after BS surgery. Very low calories diet (VLCD) and very low calories ketogenic diets (VLCKD) are the most frequently used methods for the induction of a pre-operative weight loss today.
The Importance of Protein
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.
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Supplements
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.
Post-Operative Nutritional Management
After surgery, nutritional counselling is recommended in order to facilitate the adaptation of the eating habits to the new gastro-intestinal physiology. Nutritional deficits may arise according to the type of bariatric procedure and they should be prevented, diagnosed and eventually treated. Finally, specific nutritional problems, like dumping syndrome and reactive hypoglycaemia, can occur and should be managed largely by nutritional manipulation.
General Pre-Surgery Instructions
- Shower with the antibacterial soap the pre-operative nurse at the hospital gave you when you pre-registered for surgery. Thoroughly wash your entire body before rinsing, including your navel. Please inform the office if you are allergic to the specific antibacterial soap given.
- Pack a bag for your hospital stay with any personal items you may need such as a contact lens container, sleep apnea mask and any daily medications you take. Leave all jewelry, credit cards and other valuable items at home. Remember to pack comfortable clothes to wear after your procedure and bring all educational materials that Dr.
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