If you are contemplating the huge decision to undergo bariatric surgery, you should understand that you are making a lifelong choice that will require adjustments to your diet both before and after your surgery. Depending on your current BMI, you may have to follow a 6-month diet before weight loss surgery to ensure your safety and a smooth recovery.
The experts at the Laparoscopic Endoscopic Surgery Institute offer weight loss treatments that can help get your weight under control and improve your health. Dr. Williams and Dr. Curtis each have decades of experience in obesity medicine and in helping individuals achieve sustainable weight loss using a combination of medical interventions, proven strategies, and unwavering support from a team of highly skilled and compassionate professionals.
Why You Need a Pre-Weight Loss Surgery Diet
Every surgeon will have their own preferred pre-surgery requirements, but all of them will include a clear liquid diet at some point before they perform your surgery.
All surgeons also follow the “eat or drink nothing after midnight before your surgery” rule, which is a safety requirement that exists to prevent aspiration while you are under general anesthesia, which can lead to pneumonia and life-threatening complications.
Beyond the mandatory after-midnight fasting rule, your surgeon may require you to make significant changes to your diet before your weight loss surgery. We are often asked, “What should I eat before weight loss surgery?” The exact details of the type of diet or the duration can vary depending on which type of surgery you are having, the condition of your health, and your surgeon’s preferences. There are many reasons that you may need to follow a pre-surgery weight loss diet plan, including:
Lowering Your BMI
Each surgeon will usually create a specific plan for each patient that is customized to target their needs and circumstances, and the length of the diet and the foods or liquids you will be allowed are often based on your body mass index (BMI) and the condition of your health.
Many patients must follow a very strict diet before their surgery to reduce their BMI and decrease the risk of complications. Recent research has shown that patients with a higher body mass index (BMI) are more likely to experience complications. This study also reported that these risks increased incrementally by 2 percent for each single-point increase in their BMI, which is a significant amount and should convey the seriousness of doing all you can to ensure your safety by lowering your BMI before weight loss surgery.
Shrinking Your Liver
Following a pre-surgery weight loss diet plan is also a critical step for someone who is carrying a significant amount of excess weight because it helps to shrink the liver and reduces the amount of fat that has accumulated around their stomach.
Your liver sits directly on top of your stomach, and poor eating habits often cause the liver to become enlarged, which can make it difficult for the surgeon to safely work around to access your stomach. Sticking to your doctor-prescribed diet before weight loss surgery will help shrink the size of your liver, so the surgical team can safely conduct your procedure and deliver your desired results with a smooth recovery.
What Are the BMI Guidelines for a Pre-Weight Loss Surgery Diet?
Individuals with higher BMIs have an increased risk for complications when undergoing weight loss surgery, and so the duration of pre-surgery diets is longer for people who have higher BMIs and shorter for those with lower BMIs.
Below is a sample chart with a basic outline of what the timeline of a pre-weight loss surgery diet would look like, but keep in mind that each surgeon may have different requirements.
| BMI Range | Pre-Weight Loss Surgery Diet Duration |
|---|---|
| Below 38 | May not have to follow a liver-shrinking diet, but will need to follow the 2-day “liquid only” diet just before your surgery. |
| 38-39.9 | One Week |
| 40-44.9 | Two Weeks |
| 45-49.9 | Three Weeks |
| 50 and over | Four Weeks or Longer |
What Can I Eat in the Weeks Before My Weight Loss Surgery?
The exact answer to this question can vary for each person and depend on the surgeon who is performing your procedure, but for the majority of patients, their pre-op diet schedule will look something similar to this:
- They follow a diet that is high in protein and very low in calories for a certain number of weeks before their surgery (determined by their doctor, usually based on their BMI).
- For the two days leading up to their surgery, their diet consists of only liquids.
- After midnight the night before their surgery, they cannot eat or drink anything.
What Does a Day on a Pre-Weight Loss Surgery Diet Look Like?
| Food Category | Daily Guidelines |
|---|---|
| Protein Shakes |
|
| Non-Starchy Vegetables | No limit, but excludes potatoes, corn, and peas |
| Lean Protein | Two servings of 4 to 7 ounces (fish, turkey, or very lean ground beef) |
| Healthy Fats | 1 to 2 servings of olive oil, nuts, olives, or avocado |
What Is Not Allowed on a Pre-Surgery Weight Loss Diet Plan?
There are some things you need to completely avoid during your pre-weight-loss surgery diet, which include:
- Foods: pasta, rice, tortillas, bread, refined grains, anything with sugar or dairy (yogurt, cheese, milk, etc.)
- Beverages: alcohol, sugary drinks, carbonated drinks, and drinks with excess caffeine.
- Substances
- Nicotine, THC, marijuana: if you smoke, your doctor may prescribe medication to help you with nicotine cravings.
How Will I Feel During My Weight Loss Surgery Liquid Diet?
Having to follow a “liquid-only” diet before weight loss surgery is something most people worry about, and they often wonder how they will manage it. To be honest, the first several days of this weight loss surgery liquid diet plan can be very unpleasant, and you may experience some uncomfortable but completely normal symptoms.
Your body will eventually adjust to the lower intake of calories, and these side effects should dissipate within a few days. Staying very well hydrated and drinking around 64 oz of approved beverages and liquids every day will help reduce the severity of these symptoms. The most common symptoms you may have while your body adjusts may include:
- Hunger pangs and food cravings.
- Feeling weak and tired with low energy.
- Headaches
- Stomach discomfort that may include feeling nauseous, or constipated or you may have diarrhea.
- Moodiness or irritability.
Timeline for Pre-Weight Loss Surgery Dietary Restrictions
| Timeframe | Instruction |
|---|---|
| 1 to 6 Weeks Before Surgery | Follow the diet plan provided to you by your surgeon to help prepare your body for surgery and reduce the risk of complications. |
| 2-14 Days Before Surgery | Consume only liquids and follow the specific instructions provided by your surgeon, since everyone’s circumstances are different and the surgeon will usually customize your plan. You may be limited to clear liquids only, or sometimes your diet is progressive and begins with broths. |
| 8 Hours Before Surgery | You are not to eat or drink anything because it is critical for your safety during surgery. Breaking this rule may cause your surgeon to cancel or postpone your surgery due to serious safety risks. |
What If I Cannot Follow the Pre-Op Diet Before My Weight Loss Surgery?
A pre-surgery weight loss diet helps you prepare both physically and mentally for the major changes you must make to your diet and your lifestyle to achieve sustainable weight loss and reach your goals. The main purpose of the pre-surgery diet is to reduce the risks during surgery, but it also helps to jumpstart the beginnings of the commitments you are making when you decide to undergo bariatric surgery.
The significant changes you must make to your diet before and after your weight loss surgery are not something you can skip over. Complete dedication and a firm commitment are critical for any type of weight loss surgery to deliver and maintain the results and improvements to your health you are looking for.
If you feel like you will not be able to even follow a short diet to prepare yourself for a safe surgery, you should do some serious thinking about whether you will be able to maintain the dietary restrictions that you must follow long-term after your surgery.
Undergoing bariatric surgery and having to make substantial changes to your lifestyle will not be easy, but it is absolutely possible, and many individuals have accomplished it, and so can you. Losing weight on your own, without any support system, is almost impossible, but working with professionals like those at LESI can bring real results that last.
Where Can I Find Help With Weight Loss, Before and After Surgery?
The professional bariatric team at the Laparoscopic and Endoscopic Surgery Institute (LESI) in Alpharetta, Georgia, provides ongoing support for their patients from the first consultation and throughout their weight loss journey. The experienced and knowledgeable bariatric surgeons, nurses, coordinators, and support team work together to guide you through your pre-surgery diets, lifestyle changes, nutrition education, and your recovery. After surgery, the LESI team continues to provide you with the support and resources you need to be successful in maintaining a healthy weight.
Set up a consultation today to learn more about losing weight with the help of the experts at LESI.
Frequently Asked Questions
What Happens If You Cheat on Your Pre-Weight Loss Diet Plan?
Your medical team will be monitoring your BMI in the weeks leading up to your bariatric surgery, and if they do not see the required improvements in your health, they may cancel or postpone your surgery.
It is very important that your liver is not enlarged when the surgeon attempts to gain access to your stomach, because they have to stop the surgery and repeat this process later. The diet you are asked to follow before weight loss surgery is critical for shrinking your liver and ensuring you are safe from aspiration during the operation.
What Is the Best Meal to Eat before Surgery?
The best meal to eat before your weight loss surgery depends on how close you are to your surgery date and the weight loss diet plan your surgeon gives you to follow. In the time leading up to your surgery, your meals should be high in protein and low in sugar and fat until your liquid diet starts.
What Vitamins Should You Avoid before Surgery?
There are certain vitamins and supplements that you should stop taking before surgery because they can raise the risk of bleeding or interfere with anesthesia. Vitamin E, fish oil, and herbal supplements like ginseng, garlic, and ginkgo are commonly stopped before surgery, but your surgeon will talk with you about specific ones or certain medications that you should stop taking before your weight loss surgery.
How Much Weight Do You Lose on a 2-Week Pre-Op Diet?
Most patients lose between 5 and 15 pounds during their pre-weight loss diet, but this can vary for each person. The main goal is to shrink the liver and reduce some of the excess fat that is located around the stomach to reduce the risk of complications during and after the surgery.
