Nutrition for Weight Loss Surgery

Following the right diet and eating techniques after weight loss surgery can make all the difference to your success. It’s essential that you understand that long-term weight loss doesn’t start and stop with surgery – it relies heavily on your nutrition and lifestyle following your procedure.

No matter what type of procedure you have had or are thinking about having, nutrition for weight loss surgery is a vital, ongoing component of meeting your weight loss goals.

At Weight and Metabolic Solutions Australia, we support all our weight loss patients throughout their journey with our Weight Management Program, designed to help you maintain your weight loss with the support of our professional team of nutritionists, dietitians and medical specialists.

Below is a brief guide to your nutrition for weight loss surgery. As a patient or participant in our Weight Management Program, you will receive comprehensive, step-by-step guides and tailored nutrition advice to help you maintain a healthy weight – for life.

Note – We have provided a Gastric Sleeve Diet page and a Gastric Bypass Diet page for those preparing for that specific procedures.

Nutrition for weight loss surgery - book and fruit.

Pre-Surgery Diet

It’s important that you get the right diet plan on track before you even have your surgery. As part of your pre-surgery consultation, you will be set an appropriate diet that works for you, your eating habits and the procedure you will be having.

This diet will most likely be a high-protein, low-carbohydrate diet with lots of fluids. For the two weeks leading up to your surgery, you may be put on a liquid diet with daily calories at or below 1,000. You may also be prescribed vitamins to help you get all the nutrients you need during this time.

It’s very important that you follow the diet plan you are prescribed, as it will help reduce bleeding during surgery and promote healing after your procedure. For the six hours before your surgery, you may not eat or drink anything. You can have small sips of clear water up to two hours before your surgery.

Post-Surgery Diet

Following your procedure, you will be given a detailed nutrition for weight loss surgery diet plan to promote healing and get you started on your new, permanent diet.

For the first two weeks after surgery, you will be on a strictly liquid diet to prevent complications and allow your stomach to fully heal. The next two weeks will see you move onto a pureed food diet, followed by two weeks of mashed food as you learn how much your new stomach can hold.

After mashed foods, you will move onto two weeks of soft foods, and then finally onto regular foods and your new, permanent diet. This high-protein, low-fat, low-carbohydrate diet will start you at consuming approximately 400-500 calories per day and eventually around 1000-1200 calories per day.

The diet is customised to you as the ideal calorie intake will vary between individuals.

Eat a rainbow of fruits and vegetables infographics with food and health icons set dieting and nutrition concept.

5 Factors for Nutrition Success

A good, long-term diet for weight loss involves five basic factors which dictate what you eat and how you eat.

1. Eat healthy foods

This means avoiding processed or modified foods and sticking to fresh meat, eggs, dairy, fruits, vegetables, nuts and whole grains. Get into a habit of reading food labels and if there are any more than 3-5 ingredients or any ingredients that you can’t pronounce on the label, put it back on the shelf.

You may have to change the way you prepare food as well. Don’t fry – try baking, grilling, poaching or broiling instead. Use skim milk instead of whole milk, chicken or vegetable broth instead of oil, and add flavour with spices or lemon juice rather than olive oil or butter.

You’ll soon find that you get used to and even enjoy healthy eating, and even get turned off by unhealthy foods. The trick is to just keep at it.

2. Eat protein first

Protein is one of the most important nutrients for your body, and if you don’t get enough, you can start to feel weak, tired, irritable and nauseous. With your smaller stomach, it’s important that you always eat the protein part of every meal first.

You’ll get your protein from things like meat, fish, legumes, nuts, soy and dairy products. Always look for lean or low-fat options, and if you’re having trouble getting enough protein in your diet, consider daily supplements or protein shakes.

3. Keep your blood sugar stable

Stable blood sugar means stable hunger and stable moods. To keep your blood sugar as stable as possible, avoid simple carbohydrates like white bread, white rice, potatoes, corn and peas, and anything with a lot of sugar in it.

Eat good carbs in small portions together with high amounts of protein, and mix plenty of vegetables and wholegrain foods into your diet.

4. Drink the right amount of fluids at the right times

Staying hydrated is extremely important after weight loss surgery. And that doesn’t mean just with water – about half of your fluid intake should include things like unsweetened, caffeine-free herbal tea to prevent electrolyte abnormalities from too much water.

You should be drinking about 8 cups of fluid a day, and you should never drink with meals. You must stop drinking an hour before eating and must wait at least half an hour after eating before you drink anything, or the liquids will quickly flush the food through your stomach which can affect digestion, make you feel hungrier and potentially lead to weight gain.

But it’s not as hard it sounds – you can quite easily meet your required liquid intake by measuring out your daily amount of fluids into a special bottle or container, keeping it next to you throughout the day and taking small sips every 15-20 minutes when you’re not eating.

5. Don’t snack

This is one of the fastest ways to impede your weight loss progress. Snacking between meals can lead to weight gain, so you need to make a conscious effort to only eat planned meals, at planned times.

Try keeping a diet journal and plan all your meals ahead of time to give yourself less potential for straying from your diet. When you go grocery shopping, take a shopping list – and buy only what’s on the list.

What to Avoid

As part of your nutrition for weight loss surgery, there are certain foods you will need to eliminate from your diet as well as some that you will need to limit your intake of.


  • High-saturated fat
  • Sugar, foods containing sugar and concentrated sweets
  • Fruit juice
  • Fried foods


  • Rice
  • Pasta
  • Soft, doughy bread
  • Nuts
  • Other fibrous food
  • Popcorn
  • Tough, dry, red meat
  • Carbonated beverages
  • Caffeine
  • Alcohol

Nutrition for Weight Loss Surgery: Help and Support

Weight loss is a journey, not a quick pit stop. You will need to make lifelong changes to your diet and lifestyle if you want to meet your weight loss goals and keep the weight off for good.

At Weight and Metabolic Solutions Australia, we strive to give you all the information and support you need to succeed. If you’d like to speak to someone about your weight loss surgery, nutrition or our Weight Management Program, please contact us today.