Optifast Weight Loss Shakes Review & Guide

A weight loss journey can feel pretty overwhelming, especially when you’re first starting out. It can seem like there’s so much to remember, from calorie counting to workouts, to knowing if you’re on track towards achieving your goal. That’s why the team at Optifast created what it claims to be a range of specially formulated products that are designed to help those with serious weight loss needs. So, if you’re looking for results and a helping hand along the way, Optifast might be the answer you’ve been looking for.

What is Optifast?

The Optifast VLCD Program is a very low-calorie diet (VLCD) designed to help people who are obese or severely overweight. A VLCD (Very Low-Calorie Diet) is described as a ‘low carbohydrate, total diet replacement for the dietary management of obesity’. It allows up to 800 calories per day, which must include an appropriate amount of protein, fatty acids, carbohydrates, vitamins and minerals for ‘safe and fast weight loss’.

How does Optifast work?

Optifast’s ‘total weight loss program’ is split into four levels: Intensive Level, Active 2 Level, Active 1 Level and Maintenance Level. Each stage incorporates different Optifast products and a variety of meal replacements, including shakes, snacks, desserts, soups and bars. These items are said to be specially formulated to provide patients with their daily requirements of vitamins and minerals.

According to the Optifast website, all products contain the recommended daily requirements for vitamins, minerals, trace elements, fatty acids. The products are also stated to follow the Codex Alimentarius International Standards for VLCD/VLED. But because this is a VLCD program, it’s always recommended that you speak with your doctor before starting this program or any other VLCD weight loss program.

Intensive Level

The Intensive Level is the Very Low-Calorie Diet (VLCD) aspect of the Optifast program and the first stage of the process. It’s a total diet replacement that allows approximately up to 800 calories per day, and individuals are recommended to stay on this level for no longer than 12 weeks. The daily plan involves:

  • Three OPTIFAST VLCD products
  • Two cups of low starch vegetables
  • One teaspoon of vegetable oil
  • Two litres of water.

Optifast states the Intensive Level aims to help people achieve a large initial weight loss whilst preserving lean body mass. It’s also designed to achieve to induce a mild ketosis to assist with weight loss. But keep in mind that for the first few days, you might experience side effects like fatigue, hunger, lack of concentration, nausea and headaches due to the massive change in your diet during the transition.

OPTIFAST VLCD Program Active 2 Level

The Active 2 Level on the Optifast program involves consuming a total food intake of 1000 calories per day by replacing two meals with OPTIFAST VLCD products. This diet also requires having one healthy, low-calorie meal, which contains approximately 350 calories per day. Other daily requirements include:

  • Two or more cups of low starch vegetables
  • At least two litres of water or calorie-free fluids
  • One serve of fruit (70 calories)
  • One serve of dairy (100 calories).

When combined with exercise, this phase can support patients in losing approximately 1-2 kilos per week, which is said to be a healthy level for losing weight. However, if you’d prefer to skip the Intensive Level, the Active 2 Level is said to be appropriate for people who need to achieve significant weight loss and can be used as an alternative starting point for those who find the Intensive Level too restrictive or are advised by a healthcare professional.

OPTIFAST VLCD Program Active 1 Level

If the Intensive Level isn’t suitable for you, Optifast says the Active 1 Level can be used as a meal replacement program for those with a BMI of 25-30kg/m2. The Active 1 Level of the OPTIFAST VLCD Program involves dieters consuming approximately 1200 calories per day. The length of time you stay on this level depends on your weight loss goals and lifestyle.  Your diet will involve:

  • Replace one meal with an OPTIFAST VLCD product
  • Two low-calorie meals (350 calories each)
  • Two or more cups of low starch vegetables
  • At least two litres of water or calorie-free fluids
  • Two serves of fruit (70 calories each)
  • One serve of dairy (100 calories).

Maintenance Level

The Maintenance level of the Optifast dieting program is an ongoing level where patients are encouraged to continue tracking their weight on a weekly basis and their food intake. This level requires moderate exercise to maintain a patient’s goal weight and to prevent any kilos lost creeping back.

The OPTIFAST VLCD Program Maintenance Level includes three calorie-controlled meals. Each meal should be approximately 350 calories, allowing you a total calorie intake of around 1500 calories per day. Your daily diet will include:

  • Two cups of low-starch vegetables
  • Two serves of fruit
  • One serve of dairy
  • Two litres of water.

Range of Optifast products

Optifast VLCD Bars

The ready-to-eat Optifast bars can be used as snacks or meal replacements, with each bar supposedly high in protein and a great source of fibre. Each box contains six 70g bars in flavours such as:

  • OPTIFAST VLCD Chocolate Bar
  • OPTIFAST VLCD Cappuccino Flavour Bar
  • OPTIFAST VLCD Berry Crunch Flavour Bar
  • OPTIFAST VLCD Assorted Bar Pack
  • OPTIFAST VLCD Cereal Bar

Optifast VLCD Shakes

The Optifast weight loss shakes are said to be high in protein and fibre to help you stay fuller for longer. Most Optifast shakes are available in boxes which include either 10 or 12 sachets, each containing 53g worth of flavoured weight loss shake. Although products like the OPTIFAST VLCD Chocolate Flavour Shake and OPTIFAST VLCD Vanilla Flavour Shake 18 Pack provide a larger selection with 18 sachets. Different flavours include:

  • OPTIFAST VLCD ProteinPlus Chocolate
  • OPTIFAST VLCD ProteinPlus Vanilla
  • OPTIFAST VLCD Chocolate Flavour Shake
  • OPTIFAST VLCD Vanilla Flavour Shake 18 Pack
  • OPTIFAST VLCD VLCD Assorted Shake Pack
  • OPTIFAST VLCD Caramel Flavour Shake
  • OPTIFAST VLCD Vanilla Flavour Shake
  • OPTIFAST VLCD Chocolate Shake
  • OPTIFAST VLCD Coffee Shake
  • OPTIFAST VLCD Banana Flavour Shake
  • OPTIFAST VLCD Banana Flavour Shake
  • OPTIFAST VLCD Strawberry Flavour
  • OPTIFAST VLCD Chai Flavour Shake

Optifast VLCD Soups

The Optifast Soups are available in packs of eight 53g sachets, with one sachet equal to one meal. These soups are claimed to be full of protein and come in various flavours, including:

  • OPTIFAST VLCD Vegetable Soup
  • OPTIFAST VLCD Chicken Flavour Soup
  • OPTIFAST VLCD Country Style Tomato Soup

Optifast VLCD Desserts

For anyone with a sweet tooth, Optifast provides a small selection of dessert options. Each box provides eight 53g sachets, and each treat must be prepared in advance and set in the fridge before eating. These flavours include:

  • OPTIFAST VLCD Chocolate Dessert
  • OPTIFAST VLCD Lemon Crème Dessert.


The Optifast VLCD ProteinPlus is an alternative option to the regular Optifast shakes and can be used on any level of the Optifast VLCD Program. The flavours available include chocolate and vanilla. This range is said to have similar side effects to the brand’s standard line of weight loss shakes.

How much does Optifast cost?

Optifast’s meal replacement products and snacks cost around $3.75 – $5.50 RRP per serve. This means that when it comes to groceries, the only other foods you’ll need to buy while on this program are fresh vegetables and some fruit. The Optifast program recommends low starchy vegetables such as broccoli, mushrooms, leafy greens like spinach and kale, eggplant and zucchini. Optifast’s products are available in pharmacies, hospitals or through its website.

What are the benefits of Optifast?

The Optifast ethos is all about support, so the team at Optifast has put together a comprehensive online support program, specifically designed to provide customers with a personal experience while on their weight loss journey. The online program assists customers to plan and track their progress – from their food to their training and of course – results.

Tracking results is a key factor in any successful weight loss experience, as it not only provides encouragement but can be empowering as you witness your hard work paying off. The online Optifast program also enables you to connect with an accredited Optifast VLCD Healthcare Professional, not to mention the support from other Optifast members who are on the journey with you.

Am I allowed to use the OPTIFAST VLCD program?

When you’re considering whether OPTIFAST is the weight loss brand for you, keep in mind that it’s not recommended for everyone.

Normal weight (BMI <24kg/m2)

Optifast warns that individuals with a normal weight should never use the VLCD or the Intensive Level of the VLCD Program because it can result in losing too much lean body mass. This includes people who have a BMI less than 24kg/m2.  Instead, the brand recommends chatting with an Accredited Practicing Dietitian for a suitable weight management plan.


The OPTIFAST VLCD Program should not be used by pregnant women because it apparently leads to elevated levels of ketones in the blood. While the levels are said to be low, the impact of the program on the foetus is unknown. Plus, the OPTIFAST VLCD Program isn’t catered to suit the increased nutrient requirements of pregnancy.

Optifast also recommends pre-menopausal women consider taking appropriate contraception if on the Intensive Level of the OPTIFAST VLCD Program.


The Intensive Level of the OPTIFAST VLCD Program is not recommended for women who are breastfeeding. Active 2 or Active 1 Levels may be used, but you must first ask your healthcare professional about whether either of these two programs are suitable for you.

Children under 18 years of age

Optifast advises that children under the age of 18 should stay away from the OPTIFAST VLCD Program.

Existing disease

Optifast warns against using the VLCD Program if you have liver disease, renal disease, or where porphyria is present in your body. It’s also not recommended for people who have recently suffered a Myocardial Infarction (Heart Attack) or have been diagnosed with Unstable Angina (chest Pain).

In any case, you should always check with your doctor to see if the OPTIFAST VLCD Program is safe for you to use.

Does Optifast have gluten-free or lactose free options?

All OPTIFAST VLCD products are said to contain some level of lactose and soy-based ingredients. If you have Coeliac Disease or gluten intolerance, be aware that items such as the OPTIFAST VLCD Chocolate, Cappuccino Flavour & Berry Crunch Flavour Bars are still made on equipment that also process oats. So, while these bars are not made with ingredients which contain gluten, they may still be unsuitable.

Optifast shakes, desserts, and soups are similarly made on equipment which create products containing egg. Optifast Bars are also made on equipment used to make products involving tree nuts and peanuts.

Is Optifast worth the money?

The Optifast VLCD Program is intended to assist medically at-risk patients who are required to lose weight in order to lower their risk of weight-related illnesses. It’s also catered to suit those looking to maintain a healthy weight after completing the program.

If you’re worried about having to stick to drinking the same weight loss shake each day, Optifast serves up a variety of meal replacements in a variety of flavours. You can find these shakes, soups, desserts, snacks and bars in pharmacies, hospitals or via the Optifast website.

To see how other brands are trying to help Aussies trim the fat with their sweet line of weight loss shakes, don’t forget to check out our reviews by hitting the link below.

About the author of this page

Dean Heckscher

This report was written by Canstar Blue’s Content Projects Lead, Dean Heckscher. He’s our resident expert on all things automotive, health & fitness, streaming and more. Dean is also one of Canstar Blue’s customer research report producers, helping to turn complicated subjects into easily-digestible information for our readers. He’s passionate about helping consumers make better-informed purchase decisions on all manner of consumer goods and services.

Weight Loss Shakes Compared

Picture credits: P-Kheawtasang/Shutterstock.com