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Gastric Sleeve Diet

Posted on 04 Jun, 2020


Gastric Sleeve Diet – Pre-Operative & Post-Operative Diet Information

If you have done your research on gastric sleeve surgery, you won’t be surprised to learn that diet plays an important role in ensuring the pre-operative and post-operative health of patients. 

The pre-operative gastric sleeve diet is designed to reduce the size and weight of your liver to help the operation run smoothly. The post-op gastric sleeve diet will help patients recover, form new habits, and avoid post-operative complications. The long term success of Gastric Sleeve Surgery will depend on the patients' ability to implement lifestyle and dietary changes that improve overall health.

Gastric sleeve surgery refers to a weight loss procedure that involves a surgeon removing a part of the stomach to make the stomach smaller. The amount of stomach removed depends entirely on the patient, their weight, the surgeon and the desired effects. Once part of the stomach is removed (typically between 70-90% of the stomach), the remaining small pouch is stapled back together to provide a new, smaller stomach. 

Gastric sleeve surgery is a very common weight-loss procedure in Australia. The resizing of the stomach restricts the patient’s food intake, which leads to weight loss. Rather than the stomach being a large sack that can consume large portions of food, the new stomach is rather like a tube and will fill up with small portions. 

Following a gastric sleeve procedure, the patient will experience feelings of a full stomach much earlier, significantly reducing the amount of food they consume. Given it can be a significant financial commitment, an enormous lifestyle change, and will require an operation with a few weeks downtime, sleeve gastrectomy is somewhat of a last resort for obese and morbidly obese patients. 

Losing weight after gastric sleeve surgery can significantly improve the health of a patient. Obesity is the number one contributor to type 2 diabetes, heart disease, high blood pressure, high cholesterol, arthritis, and asthma. Those who are considered for gastric sleeve surgery are typically those who are morbidly obese, have attempted numerous weight loss routes, or will experience severe life-threatening conditions if they do not lose a substantial amount of weight. 


What Does Diet After Gastric Sleeve Look Like?

One of the biggest elements of a gastric sleeve procedure is the diet after gastric sleeve. In essence, gastric sleeve surgery is entirely changing the nature of a person’s digestive system. To say that diet plays a role before and after gastric sleeve procedure, would be an enormous understatement. 

Before the procedure, the clinic will provide the patient with a comprehensive diet to follow to minimise surgery risk and get the digestive system ready. Following the surgery, the patient will need to stick to a strict liquid diet after gastric sleeve to help the digestive system to recover. From there, the patient will need to make some drastic lifestyle and diet choices to aid their body in losing weight and maintaining a healthy body. 


Gastric Sleeve Diet Pre-Operation



The main objectives of dieting pre gastric sleeve operation are to reduce the risk of complications and to shrink the liver. On average, those that are overweight have a greater risk of experiencing complications during surgery than those of healthy body mass index. Furthermore, if you’re obese, your liver will likely have an accumulation of fat cells both in and around it – making it larger than it needs to be.

The liver sits right next to the stomach. A liver that is too large will make the gastric sleeve procedure more time-consuming, unsafe and complicated. Often before bariatric surgery, the patient will be assigned a diet that is low in carbohydrates, low in fat and moderate in protein, in an effort to shrink the size of the liver. Strictly following this kind of diet makes the surgery safer, the patient healthier, and ultimately prepares them for the diet they will be assigned for the first weeks after the surgery. 

To prepare for the gastric sleeve procedure, the patient will begin a strict diet to begin minimising portion sizes. This will involve the assistance and guidance of a licensed dietician and clinical psychologist. Two days before the procedure, the diet will switch to a clear, liquid diet. This may include protein shakes, water, broth, decaffeinated coffee and tea, jelly, and other approved liquids. 


Gastric Sleeve Post Op Diet

The gastric sleeve post-op diet will vary from patient to patient but can generally be categorised by weekly stages of the diet to help the body heal from the procedure. The first couple of weeks will involve a nutritious and mapped out liquid diet after gastric sleeve, containing water, broth, milk, fruit juice, jelly and decaffeinated tea and coffee.



The following two weeks will involve soft, mashed and pureed foods to help your body to adapt to more textured foods. This post gastric sleeve diet will include things like yoghurt, pureed vegetables or meats, light smoothies, and thin soups. Week five to six of the diet after gastric sleeve surgery will have you moving to more tender cooked foods. This includes soft noodles, mashed potatoes, scrambled eggs, and basically any soft, lean proteins. 

The gastric sleeve post-op diet aims to slowly introduce foods and textures to the stomach lining. Slowly moving from liquids to purees to solids will help to avoid the stomach lining to experience irritation and stress. Furthermore, during the post gastric sleeve diet, the patient will need to relearn food consumption behaviours and become more aware of their portion sizes. The stomach pouch has been significantly reduced in size, and the patient will have to get used to eating much smaller portions and knowing when to reduce intake. 


The Best Diet to Follow After Gastric Sleeve Surgery

The best diet to follow after gastric sleeve surgery is the one that your clinic has set out with you. The clinic you work with will provide a multidisciplinary tailored approach to your weight loss journey, with the help of a surgeon, physician, dietician and psychologist. While there is plenty of useful information online about gastric sleeve post op diets, the best course of action is to strictly follow the guidance your clinic has set out for you. Your surgeon will provide you with the best diet to follow after gastric sleeve surgery – by sticking to it, you can ensure you are giving your body the best chance of supporting a healthy weight loss journey.


The Liquid Diet After Gastric Sleeve Surgery

In week one, following your surgery, you will be limited to a clear liquid diet after gastric sleeve surgery. Within this first week, your stomach may be very irritable, so it’s essential to stick to the liquid diet after gastric sleeve surgery. While it may sound tough to consume only clear fluids for an entire week, most patients will experience very little desire to consume much more. The hunger hormone that is ghrelin can be almost non-existent post gastric sleeve surgery, as the part of the stomach that produces most of this hormone is generally removed. 

During this first week, it’s important to stick to the following items and ensure they are sugar-free:

  • Water
  • Broth
  • Jelly
  • Decaf tea
  • Decaf coffee
  • Sugar-free ice-poles
  • Sugar-free drinks that are not carbonated

It’s also important to avoid:

  • Carbonated drinks
  • Overly sweet beverages
  • Sugar
  • Caffeine

After the first week, you’ll likely be moved to a full liquid diet after gastric sleeve surgery. During this week, it’s not uncommon for patients to begin experiencing their first signs of hunger pains. However, it’s important to remember to strictly stick to the post gastric sleeve diet set out by the surgeon’s team; this will ensure your stomach begins to slowly get used to its new digestive system. Full liquids will include: 

  • Protein shakes (sugar-free and with water)
  • Sugar-free pudding
  • Yoghurt
  • Soup with soft noodles
  • Creamed soup
  • Sugar-free sorbet
  • Watery oatmeal/porridge
  • Natural juice
  • Sugar-free, non-fat ice cream



This liquid diet after gastric sleeve may or may not coincide with the liquid diet you were assigned prior to the surgery. Ensuring that your body gets used to digesting these liquids before adding solid foods is crucial to helping your stomach heal properly. 


3 Weeks Post Gastric Sleeve Diet

After the first two weeks of the post gastric sleeve diet, the patient can finally introduce soft pureed foods into their diet. Patients will need to continue limiting sugars and fats; however, they will be looking at introducing more protein into their meals. The goals for three weeks gastric sleeve post op diet include:

  • Introducing new foods one by one
  • Eating slowly and mindfully 
  • Increasing protein intake

It’s important to introduce new foods into the diet one at a time and slowly, as the new stomach pouch can react differently to how it might have done before the surgery. Food may taste different, it may be tolerated differently, and food groups may be more difficult to digest than they were before. 

By eating slowly and mindfully, you can speculate how each food reacts with your new stomach lining. Taking care with each meal will identify foods that cause gas, stomach upset, diarrhea or any other reactions. The diet for three weeks post sleeve gastrectomy will look like:

  • Protein shakes with either water or non-fat milk
  • Almond milk, coconut milk
  • Hummus
  • Cottage cheese
  • Soft cereals
  • Oats
  • Soft vegetables (steamed or boiled)
  • Soft cheeses
  • Ground chicken or beef
  • Soup 
  • Scrambled Eggs
  • Steamed fish
  • Canned tuna and salmon
  • Mashed fruit (bananas, avocado, canned fruit)

During this period, it’s important to avoid:

  • Sugar
  • Starchy foods including pasta, rice, and bread
  • Fibrous vegetables including celery, broccoli, asparagus, raw leafy greens


6 Weeks Post Op Gastric Sleeve Diet

At this point, patients will be able to consume and enjoy more solid foods. The 6 weeks post op gastric sleeve diet will focus on putting the new-normal eating plan into long term effect. It’s important to keep the emphasis on lean protein, vegetables, and nutrition-dense meals. Continue to introduce one food at a time to monitor the body’s reactions, while also avoiding sugary sweets and soft drink. 

The 6 weeks post op gastric sleeve diet is less of a strict food group and will focus more on adapting your new food choices into a healthy lifestyle. This is where a lot of patients get stuck and fall back into poor eating habits – it’s important to remember that your body needs good nutrition and to be well looked-after to continue supporting your weight loss journey.



Gastric Sleeve Diet After One Year

Following gastric sleeve surgery, it is important for a person to not only change the food that they are consuming but also how they are eating it. The gastric sleeve diet after one year will focus on healthy eating habits and behaviours to reduce the risk of unnecessary weight gain or complications. 

At the one-year mark, the gastric sleeve surgery clinic will assess how the patient is adjusting to their new lifestyle and ensuring that they are making the right food consumption choices. These eating behaviours for the gastric sleeve diet after one year include:

  • Consuming between four and six small meals a day, instead of three large ones
  • Chewing thoroughly and slowly
  • Ending a meal upon feeling full
  • Choosing nutritionally balanced meals
  • Eating high protein count foods
  • Avoiding unnecessary eating due to stress or boredom
  • Taking dietary supplements, depending on dietician’s advice
  • Drinking at least 1.5 litres of water every day
  • Avoiding drinking fluids within 15-30 minutes of a meal, as this may lead to overfilling stomach pouch and vomiting

While it’s all good and well to eat well immediately following your gastric sleeve surgery, the one-year mark post-operation will provide a good indication on whether or not you have the ability to make the right lifestyle changes for your body. Many view gastric sleeve surgery to be a weight loss solution; while in reality, it requires an entire change of lifestyle. The gastric sleeve diet after one year will ultimately reflect the diet one will be following for the foreseeable future.



Not Following Your Gastric Sleeve Diet 

Failing to follow your set out gastric sleeve diet or “cheating” the guidelines can come with some serious consequences. Don’t forget – your body has been surgically altered; if you’re not committed to making serious lifestyle changes, you will only do yourself harm. Not following the gastric sleeve diet can result in diarrhea, severe dehydration, constipation, bowel obstruction, or a very serious gastric leak. 

The gastric sleeve diet is a multiphase diet that experts have designed to prepare for the surgery, speed up recovery, and ease the transition to a lifetime of healthy and mindful eating. Introducing food groups slowly enables the body to get used to its new sized stomach and digestive system. The diet after gastric sleeve surgery that is specifically mapped out for you before and after your procedure will be tailored to suit the needs of your body, your nutritional intake, and your new lifestyle. Following these phases of the post gastric sleeve diet and the expert advice of your clinic’s dietician is crucial to the success of your procedure and weight loss journey.


Central Coast Surgery Gastric Sleeve Diet

Gastric sleeve surgery is a life-changing procedure. The surgery makes it easier to lose weight, get moving, and make better lifestyle choices. A healthy pre-op and post-op gastric sleeve diet ensures a safe recovery and will steer you in the right direction for long-term weight loss success. 

If you’re interested in gastric sleeve surgery or weight loss surgery, get in touch with one of our leading consultants at central coast surgery today. We are the bariatric specialists providing exceptional weight loss solutions and lifestyle changes from Sydney all the way up to the Central Coast.