What diet do I need to follow post the Gastric Sleeve Surgery?

Full details of the best diet to follow post surgery moving from fluids onto a normal full diet, please refer to the handouts and recipes section

I am on fluids post surgery and I am struggling to hydrate enough, what do I do?

Post surgery, you will have experienced swelling at the scar line of the sleeve.  This reduces the volume of liquids your sleeve can tolerate at one time.  The total expected volume of 1/2 cup long term, could be as little as 3 sips in the early days post surgery. Remember every individuals experience will differ, so the impact of swelling will vary. Some people recover faster than others.

The first step to help reduce swelling faster, is to consume ice cold drinks, suck on ice cubes, zooper doopers, ice poles, hydralyte zooper doopers.   You may bethinking, I want o lose weight, why would I have sugar in the form of ice poles.  This can be answered in two ways:

  1. If you are struggling with hydrating adequately, but it is not bad enough to be re-admitted into hospital, the extra sugar is crucial for energy levels and absorption of water
  2. If your energy levels are fine, you have diabetes, then just suck onto water based ice cubes and diet icy poles, which will control the blood sugar levels also.

To support an increase in liquid intake, please graze all day long, as your sleeve will struggle with volumes in one sitting.

As the swelling settles, you will be able to consume more liquid in one sitting, which will help hydrate you better.

I find it too difficult to drink my 2L of water per day. What should I do?

During the liquid phase post surgery, anything you drink is hydrating you.  You do not need to drink 2L of water in addition.  Also it is very common for plain water to feel very heavy, metallic and even feel uncomfortable when it is drank.  To address this you can add a splash of cordial, juice or protein water into the water to help lighten the water. When the swelling in the sleeve settles, plain water will feel more comfortable.  Until then, Fiji water can also help.

Long term, it can be very difficult to drink 2L of water post surgery.  Please keep in mind that if your urine is pale yellow in colour and you o not feel thirsty, then you are adequately hydrated.  To achieve this, grazing on water all day is very important rather than trying to drink 1L in a very short period of time.

I recently have had surgery and very fatigued. What can I do ?

Experiencing fatigue in the early weeks post surgery is quite normal, due a sudden drop in calories.  When able, try and add the following three nutritional items in your diet consistently, as this will help increase your energy level:

  1. One meal replacement shake per day
  2. Protein powder (water or dairy based – any brand that you like the flavour of)
  3. Multi Vitamin specific for weight loss surgery.

Your goal as a minimum would be to achieve a total of 70-80gm protein per day.   Try and achieve 50gm protein from the combination f the shake and powder.  You may consider adding extra protein into the shake, to a maximum of 40gm of protein in one drink.  You can consume the shake as a meal or even as a snack after a good bout of exercise as a recovery drink.  Your body will be certainly asking for it.

Which is the best Multi Vitamin that I should take?

In Australia there are two key brands:

  1. FitForMe.com.au,
  2. BNmulti.com


The key differences are:

  • Fit for me is a once day tablet
  • BNmulti is twice a day
  • Both companies  have chewable and capsule options
  • Fit For Me has removed the iron from the chewable and coated it to be absorbed lower in the intestine to reduce the chances of nausea.

To ensure you achieve your maximum nutrition, the convenience and taste of fit for me, would be ideal for you.  Both supplements can only be purchased online using the links above

When should I begin taking the Multi Vitamins?

Commence your chewable multi-vitamin when you get home from hospital. If you like the flavour continue with these on an ongoing basis. If you prefer a tasteless version, there is a capsule available that is an amazing multi-vitamin for anyone who has had weight loss surgery.

The multi vitamins make feel nauseated, what should I do?

If you have just hard surgery and the supplements are causing nausea, please consider any of the suggestions below:

  • use the fit for me chewable, as it separates the iron into a very small white tablet that you swallow.  It is coated in a manner to help the iron be absorbed lower in the intestine to support, to lower the chance of nausea.
  • Break the fit for me into 2 sitting to lower the concentration
  • Ensure the multi vitamin is consumed with liquid or food, it will help reduce the impact of nausea
  • Consider swapping the chewable multi vitamin to the capsule.
  • Commence the capsule once off liquids

If you are weeks after surgery, swap from the chewable to the capsule version.  If the supplements specific for weight loss surgery still create nausea, it is best to discuss your needs with your dietitian / medical team.

I am experiencing diarrhea after surgery, what can I do?

Diarrhea can be caused by a number of things as indicated below:

  • LACTOSE INTOLERANCE:  All the Optifast shakes have a high level of lactose, so these can be replaced with the Optifast bars, chicken soup or desserts, to help lower the lactose content.  You can also add lacteeze tablets into the Optifast shakes to help break down the lactose.  Lacteeze tablets can be bought from your pharmacy.


  • IBS: If you do experience some irritable bowel disease symptoms caused by known trigger foods, please avoid these from your choice of foods


  • SURGICAL REASONS:  Post surgery the pressure in the sleeve is increased. For this reason liquids/foods can be pushed out of the sleeve too soon, which can cause diarrhea.   This can happen at any time randomly.  Post surgery, often 4 to 6 weeks later, things just settle.  If they do not and the situation is affecting your lifestyle, please discuss this with the medical team.


I have become constipated, what should I do?

The best thing to do is to get on top of the situation as soon as possible.  Commence a laxative to support your bowels opening up.  When the laxatives are commenced, when your bowels open, do not immediately stop these. It is recommended to slowly wean off them, to allow time for your body to adjust to a lower food intake hence a reduce output.

To support an increase in fibre, you may consider the addition of Benefibre.  This is ideal for the sleeve as it does not gel up and place pressure on the cut

I am tolerating liquids really well, can I move onto pureed food sooner?

No.  It is strongly recommended to remain on the liquids on the full time frame.  Progressing too quickly will possibly increase your risk of a delayed leak.  If this occurs, it does take months to recover.  Also if we progress too quickly, the swelling in the sleeve can be aggravated, which will only delay progression onto a full diet.

How do I know my sleeve is ready to progress onto the next phase from liquids, pureed and soft solid to a full diet?
  • Once you can handle a ½ cup of liquid comfortably in a single sitting consumed in 15mins MULTI PLE TIMES DAY, this will indicate that any swelling that resulted after surgery is settling down, hence the capacity of the sleeve has increased and you will be able to tolerate solid food slowly. The reduction in swelling also allows more peristalsis to allow digestion and movement of the food down the sleeve.


  • If you rush the progression and you can’t tolerate liquids correctly and if you tried to progress onto stage 1 food too quickly, it will hurt and be very uncomfortable and put you at risk of the sleeve leaking. The sleeve does not have the strength/movement to move the food down the sleeve.


  • Do not rush progressing onto solid food prematurely. The more solid food will make feel very nauseated and uncomfortable and your nutritional well be will be compromised further. If you progress to solid food prematurely before your body is ready, it will feel like lead in the chest area as the food just sits like


  • If it takes close to 30mins to consume ½ cup of liquid, you are not ready to progress. Wait until you pass the above test and begin to progress.


  • The same test must be used to assess if the swelling has reduced at the end of each transition phase from pureed and soft solid.  For example when  on pureed food for the appropriate time frame, the test to assess if you can progress onto soft solid food is to be able to handle 1/2 cup in 15min comfortably.


  • As you progress between each stage, it is normal for the volume of food you can handle in one sitting reduces before it increases back to 1/2 cup total in a meal time.
Is it ok to graze?

Immediately after surgery up to the point you are on a full diet, eating normal solid food, yes it is ok to graze.  The reason, this allows time for the swelling to reduce to allow you to eat sufficient amounts of food to be satisfied.

Long term, grazing on food between meal times from habit, boredom emotional reasons will slow down the weight loss and on some occasions, cause weight regain.

Can I drink and eat at the same meal time?

No, not ideally.  Drinking at your meal time will move the food through the sleeve faster causing an increase in calories consumed and you will feel hungrier earlier.

After your meal is eaten, waiting 20-30mins is ideal

Before you eat, waiting 5-10mins only is sufficient.

I am struggling to eat enough food to get my protein in, what should I do?

Unless you stretch the sleeve it is impossible to consume enough protein from normal solid healthy food. So the only way to consume enough protein is to drink your protein by including a high protein drink per day. The drink would should have a maximum of 40gm protein in one sitting. Beyond that your body can’t absorb any more. Per day, try and consume 70 to 80gms of protein per day.  Some examples of protein powder and bars can be seen under the supplement tab

Can I drink alcohol?

Yes you can. It is best to wait until you are on a normal unrestricted diet. Be mindful that you affected by the alcohol. For example if you drink one standard drink, you will feel as though you have had 2 to 3. So, do not drink and drive.

Can I drink soft drink?

Yes you can drink soft drinks, however it will not feel very comfortable. The gas gets trapped in the sleeve and feels very undesirable. Yes, even if it is diet soft drink. It is encouraged you do not have any soft drink of any type, even diet soft drink. Sweet drinks lean you towards less desirable food choices and the diet brands make you hungry.

My weight loss is slow, what can I do to pick it up?

Everyone will lose weight at a different rate. A starting weight above 130kg will always experience a greater weight loss initially, compared to a starting weight of 100kg.  so please keep this in mind.  It is also best to not compare yourself to others, as this can create frustration and possibly derail you.  Always look at the ultimate goal, of losing your excess weight and keeping it off.  For some this does occur at a slower pace.  So what should you expect:

  • Your weight loss journey will always start from the pre surgical VLCD.  On average, you are looking at  3 to 4 kilograms weight loss per month.  Some months will be slower than others.  This is normal.  So reflect on this at the 2, up to 8 month mark as a guide.  If you weight loss stalls for two weeks, it is ok, always look at the average.
  • As you get closer to your ideal weight, your loss will always slow down.
  • At the 3 week mark post surgery, weight loss can stop. This is ok.  It will pick up again.
  • On the scales your weight will always oscillate 1/2 to 1 kilogram up and down.  This is normal.  So if you see your weight increase by 200gms, this is not weight gain.  In fact quite normal.
  • If you are a few months after surgery, and you would like to increase your weight loss, you may consider 16/8 intermittent fasting.  Click here to view more details. A food diary recording exactly what you have eaten as the day progresses will highlight if anything needs improving.
  • If you can become more physically active and incorporate some light weight as medically able would be ideal.
My weight loss has plateaud. But why, I am hardly consuming any calories?

If your weight loss has stopped and you are in the early weeks post surgery, this can be normal.  Your body is still recovering from surgery.  Also please reflect on the amount of weight you have lost since you started the VLCD pre surgery.  Does this meet the 3-4 kilograms per month on average?  Most likely.  A short stall in weight loss is normal.  It will pick up.

Also if the calories are too low, such as 500calories or less, your body can think you are in starvation mode and slow down the weight loss for survival reasons.  Do work on increasing these a little where possible.  However if the swelling is intense with the sleeve, this can be difficult. So nutritious calorie controlled options of the 3 key aspects, will help:

  • a shake per day
  • protein powder
  • Multi Vitamin for the sleeve

Also question if your weight loss has actually plateaud. The scales may not be moving, but if you find your clothes are feeling looser, then you are not on a plateau.  A true plateau is when you are not losing weight on the scales and your clothes are not feeling loser.  Also if neither of the two aspects change for atleast 2-4 weeks, then yes it is a true plateau, of not losing weight.  it will be time to reflect on the following:

  • review food intake – keep a 2 week food diary
  • review exercise levels – can they be changes or increased
  • any non-hungry eating occurring
  • are liquids calories sneaking in: sugar in hot drinks, soft drink, juices or alcohol
  • Consider 16/8 intermittent fasting
  • Consider the shake VLCD diet for 3 weeks

If nothing can be improved, just keep going and the weight will slowly trickle off through your consistency of keeping to an amazing lifestyle.

How can I minimize hair loss?

Include the top 3 things as soon as possible and consistently to minimize hair loss:

  1. One shake per day
  2. protein powder  (1 and 2 to provide 50gm protein in total)
  3. Multi vitamin specific for the sleeve surgery

In addition please consider the following:

  1.  Consider a blood test to ensure there are no nutritional deficiencies.
  2. Possibly add in hair nail and skin supplement
  3. ensure diet is balanced
  4. Consider extra supplementation, after your diet is reviewed with a dietitian.  You could possibly be doling everything correctly, but the weight loss is so significant that the body resort to survival mode.  A consultation with a Dietitian is crucial at this stage.
How many calories should I be aiming for?

1000 to 1200 calories would be a guide.  Under the gastric Sleeve Presentation, there is a video explaining this in detail.  Please click here to view.

Should I avoid carbohydrate rich foods to lose weight?

Absolutely not.  Carbohydrate rich foods such as, pasta, rice, bread, grains, fruit, potato, corn and legumes as some examples, when eaten in a solid amount of 1/4 cup portion at a meal, this is not a lot of food.  If carbohydrate rich foods are avoided,  then your diet will only consist of animal protein such as meat, chicken, fish, egg, tofu (vegetables) with carb free vegetables.  If this suits you, then please feel free to limit your food choices and follow this plan

However if you enjoy variety and would like to add a small amount of carbohydrate, this will be absolutely fine.  The key is to chew not drink your carbohydrates.

For example eating whole fruit of 1/2 cup portion really limits the calories.  If you drank 1/2 cup orange juice, that could provide the calories of 2-3 pieces of fruit.

Details of managing calories and carbohydrate rich foods plus the fatty and sugary food are detailed in the video under the Gastric Sleeve Presentation, 

I am noticing, that I can eat more food and I am feeling hungry ?

Yes, this is a very common experience. Lets work through very important question in stages.

  1. You will find it easier to eat more volumes of food once the swelling in the sleeve completely settles.  This is the time to be very diligent with the amount of food is eaten. Do measure out 1/2 cup of food as an ideal portion.
  2. It is important to not feel full after a meal.  feeling full is a sign of over eating
  3. Feeling full often with solid food, will certainly stretch the sleeve, you will be able to eat much bigger volumes.
  4. The goal is to feel satisfied after a meal not full and use this as  guide to how you should feel after a meal
  5. When you feel hungry, review what was the previous meal eaten. Was it solid in nature or more of a liquid consistency?  Liquids pass through the sleeve quickly and yes you will feel ready to eat sooner. Often when people feel less restricted, it is interpreted as feeling hungry. This is incorrect.  It does take time to learn what these new feelings mean.
  6. If truly feeling hungry and eating the ideal types and amounts of food, then feel free to include an additional snacks as needed
Can the sleeve stretch and increase in size?

Yes, absolutely.  The sleeve increases in size from feeling full after a meal and eating solid food, not liquid based meals such as a latte or soup.

Liquids can pass through the sleeve quickly and this total volume can be more than 1/2 cup. This is normal once the swelling settles.  This doe snot indicate that the sleeve has increased in size.

The sleeve has stretched when you can eat more than 1/2 a cup of solid food in 15mins.

If the sleeve has stretched, 16/8 intermittent fasting can help reduce the sleeve size again reset it. For details of the fasting, click here.