Disclaimer: The content of this website is not a substitute for medical advice that is relevant to you and your situation. Please discuss any questions or health concerns you may have with your Alevia bariatric doctor.

Gastric Sleeve vs Gastric Bypass Surgery

Bariatric surgery is considered a treatment option for people who live with obesity, and for whom treatments such as lifestyle change and/or anti-obesity medication, have not been effective.  Both gastric sleeve and gastric bypass surgery have the same goal: to help you to lose weight, through altering the hunger and appetite hormones involved in weight regulation, however, the difference lies in how the procedures are completed.

The gastric sleeve surgery, or “sleeve gastrectomy”, is a common weight loss surgery recommended for people who live with obesity. It involves removing up to 85% of the stomach to make it smaller, which helps people lose weight by limiting the amount of food they are able to consume, and increasing feelings of fullness. 

On the other hand, gastric bypass surgery is completed by creating a small pouch in the stomach and  connecting it directly to the small intestine, bypassing the first part of the small bowel, so that food reaches the gut more quickly and increases feelings of fullness and reduces hunger. 

In Australia, gastric sleeve surgery and gastric bypass surgery are done laparoscopically (keyhole surgery), where a small video camera and surgical tools are inserted into the abdomen. 

Diet After Bariatric Surgery

After your bariatric surgery, it is crucial to follow a specific diet, as prescribed by your healthcare team, to optimise your weight loss success. The guidelines for this diet will be carefully planned by your doctor or dietician, giving you balanced meals that will be lower in calories but still high in protein to help prevent loss of muscle mass. The diet also helps your stomach to heal after having the surgery. Your bariatric diet might seem overwhelming at first, but you will progress through the stages quickly and be eating a healthy diet, – but much lower in calories than before –  and on the road to success with long term weight control.  

Though the post-surgery treatment plan will vary between patients, here is a general guideline of what to expect with your bariatric diet. 

There are 4 main stages in a post-surgical diet, namely:

  1. Consumption of clear fluids/full fluid diet. Following this diet, the patient will only be able to consume fluids that are thin enough to be consumed through a straw.
  2. Puree diet – The patient may be able to consume pureed foods, combined in a blender. 
  3. Soft diet – In a soft diet, the patient’s diet will slowly normalise in terms of texture and will allow for small amounts of soft food.
  4. Normal diet – The final stage of the bariatric diet, which will now include portion-controlled solid foods. 

Full Fluid Diet

Your new stomach has staples that need to be protected from solid and bulky food textures after your bariatric surgery. You will need to allow at least 6 weeks for the staples to fully heal and the swelling to reduce. If you eat anything that is too solid or textured, then there is a chance that you will develop severe pain or even a breakdown of the wound that can lead to rehospitalisation. 

So in the first two weeks you may be required to stick to a strictly fluid diet. 

Fluids you can consume during this stage include:

  • skim milk
  • thin soup and broth
  • unsweetened juice
  • sugar-free gelatin
  • sugar-free icely poles
  • meal replacement shakes

You will need to take small sips of your fluids to ingest slowly. Carbonated drinks and beverages with sugar should also be strictly avoided during this stage of the diet plan. Once your body can tolerate drinking fluids, your doctor or dietician may prescribe pureed foods to be included in the diet. 

Pureed Diet

In weeks 2-4 your staples are starting to heal, however eating solid and textured foods is still not recommended. Your food should be combined in a blender to make a puree, similar to the texture of baby food. Foods can include:

  • Stewed or casserole meats, chicken or fish 
  • Lentils or legumes mashed or pureed 
  • Yoghurt, ricotta or cottage cheese
  • Grated, mashed or pureed fruits eg. stewed apples
  • Grated, mashed or pureed vegetables  eg. grated carrot.

However, you may want to avoid fruits with lots of seeds, such as strawberries or kiwi fruit. But the good news is – you can begin chewing again! 

Soft Foods Diet

By week 4-6 the staples finish healing and your stomach swelling has reduced, so you can now re-introduce and enjoy eating some soft foods like vegetables, fruit, grated salads, chicken, fish and soft-boiled eggs. You can also incorporate protein shakes once a day. You’ll still need to avoid eating fibrous vegetables like broccoli and cauliflower, as they are harder for your body to digest. 

It is important to remember to eat slowly and chew your food well to avoid placing any stress on your stomach. Hydration is also essential; you should aim to drink 1-2L of fluids everyday.

Solid Foods/Stabilization

At this stage, your staples are likely to have completely healed with minimal swelling. 

This means you can eat textured food again! But before you rejoice, it is still essential to keep in mind that your new stomach size can’t handle the same portions of food that your pre-surgical stomach could have. Make sure you maintain a slow pace when eating, chew your food well and eat nutritious, balanced meals to fuel your body. 

Steer clear of foods that lack nutritional value and are tougher to digest, such as:

  • corn on a cob
  • popcorn
  • fried foods
  • tough meat
  • carbonated drinks
  • dried fruit
  • crunchy food
  • bread and bread products

Your Alevia doctor and bariatric surgeon will help guide you through your post-surgical weight loss journey and advise you as to when you can resume eating normally. 

For ongoing weight management care after bariatric surgery or for a less-invasive medical alternative, get in touch with one of our bariatric doctors who can provide you with compassionate and independent advice on the most suitable way for you to lose weight.