Nutrition Information for Bariatric Surgery

Bariatric surgery is just the first step in the treatment of obesity. Your commitment to a healthy diet and following the recommendations specified by your dietitian and surgeon will result in greater success with weight loss and maintaining it in the longer term. Patients who attend regular follow up appointments with the dietitian are likely to have more success with weight loss.

Pre-Approval Stage (for public patients only)

In the pre-approval stage, your GP will be referring you to a team of health professionals to assist you with a weight loss plan. Working with a dietitian and psychologist, you will start to make dietary and lifestyle changes which will help you to lose weight pre-surgery and maintain healthy eating habits after surgery.

If you have been referred to see a dietitian at Joondalup Health Campus (JHC), we recommend that you attend 3 appointments to be assessed and managed as part of the pre-requisite for you to be considered for bariatric surgery. Speak to the Joondalup Bariatric Services staff to make an appointment with the JHC Dietitian and please inform the receptionist that you are in the 'Pre-Approval Stage'.

Preparing for Surgery

You will be asked to commence on a Very Low Energy Diet (VLED) using meal replacements about 2 to 4 weeks prior to your surgery and your surgeon will advise you of the duration required for this. Your dietitian will discuss the details of the VLED diet in your pre-admission appointment. Please book your first review appointment with the dietitian for Week 2 post-surgery as soon as you have attended the pre-admission appointment.

Speak to your surgeon or staff at the Special Medical Assessment Clinic about when you will need to start fasting in preparation for your surgery.

After Surgery

Day of Surgery to Week 2 Post-Surgery:
After your surgery, you will be admitted to the ward and allowed to commence on nourishing fluids. You will be having small sips of low fat, nourishing, high protein fluids frequently throughout the day. Fluids should be lump free and no thicker than thin yoghurt. Your dietitian will provide further information at your pre-surgery appointment.

  • All procedures: Fluid only diet for 2 weeks, aiming for a minimum of 1.5L fluid/day with the majority of fluid being high protein nourishing fluids.
  • Remember that the goal at this stage is to maintain hydration and consume adequate protein to preserve muscle mass and assist with healing post-surgery

Weeks 3 to 4 Post-Surgery:

You will start on small serves of puree food, aiming to have 3 main meals daily. Include a variety of puree fruit and vegetables, porridge, soup, puree meat, fish and low fat dairy products in your diet. Portion sizes recommended for main meals are:

  • Lapband: ½ cup of puree food at each main meal.
  • Gastric sleeve and gastric bypass: ¼- ½ cup of puree food at each main meal and include high protein drinks between meals.

Week 5 Post-Surgery:

You will be commencing on soft, moist food for main meals, 3 times per day. Include a variety of soft, mashed fruit and vegetables, weetbix, soup, soft boiled egg, minced meat, fish or chicken.

  • Lapband: Aim to have 1 cup of food at main meals.
  • Gastric sleeve and gastric bypass: ½ cup of food at each main meal and include high protein drinks between meals.

From Week 6 onwards post-surgery (long-term):

  • Lapband: You will continue to have 3 small meals per day, aiming to have 1 cup of solid food at each meal. Avoid grazing and you will not require regular snacks unless you are unable to meet your nutrition requirements with main meals.
  • Gastric sleeve and gastric bypass: You will continue on 3 small meals per day, consuming up to ½ cup of solid food at each meal. You will require high protein snacks or nourishing fluids between meals.
  • Include a protein source at each main meal and aim to eat the protein portion of your meal first.
  • Frequency of subsequent review appointments will be advised by your dietitian.


  • It is important to stick to the recommended portion size and advice provided by your dietitian to avoid any complications. You are likely to overstretch your stomach if you overeat. Stop eating once you have consumed the amounts recommended above or once you feel satisfied.
  • Chew your foods well; from Weeks 3-4 onwards, it should take you about 20 to 30 minutes to eat your meals.
  • It is important that you continue to choose healthy, low kilojoule food after surgery.
  • Remember to sip on low energy fluids such as water, diet cordial, tea or coffee (without sugar) frequently throughout the day to maintain hydration.
  • From Week 3 post-surgery, avoid drinking fluids with meals. Fluids are best taken ½ hour before and 1 hour after meals.
  • Avoid drinking carbonated drinks or using a straw when drinking as it can cause bloating.
  • For patients having lapband surgery, you may find some foods difficult to tolerate long-term including bread, tough meats, chicken breast, rice, pasta, nuts, popcorn or carbonated beverages.
  • Avoid food and drinks containing high amounts of concentrated sugar (e.g. juices, honey, soft drinks, cordial or lollies).
  • Advise your surgeon or dietitian if you are experiencing nausea, vomiting, palpitations, diarrhoea or sweating associated with eating.
  • If you experience any changes in bowel habits or nutritional issues such as ongoing difficulty with tolerating food, please make an appointment to see your Dietitian or JBS surgeon.


  • After you are discharged from hospital, you will need to commence on a comprehensive multivitamin (chewable or liquid) and calcium and vitamin D supplement. Chewable gummies or children's multivitamin are not adequate for your needs. Additional supplements may be required and you will be advised by your dietitian or surgeon.
  • If you have diabetes, you will need to monitor your blood sugar levels regularly. Make an appointment to see your GP before commencing on a VLED and after surgery to review your diabetes medications.
  • Depending on the type of surgery you had, you may be at a high risk of nutrient deficiencies. Your dietitian will discuss this with you and may recommend that your GP perform a blood test every 6 to 12 months.  


This handout contains general information only. For more specific advice regarding your diet post-bariatric surgery, please make an appointment to discuss this with your dietitian.

This document remains the property of the Dietetics Department at Joondalup Health Campus and may only be reproduced with prior approval and appropriate source referencing.

Disclaimer All information contained in this handout is current at the time of revision. If you have concerns about your health, you should seek advice from your general practitioner or health care provider. If you require urgent care you should go to the nearest Emergency Dept. Created: [February 2014]  

Joondalup Bariatric Services
Suite 26, Level 2, Joondalup Private Hospital, 60 Shenton Avenue,
Joondalup WA 6027

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