By Melanie McGrice, AdvAPD

As you know, OPTIFAST VLCD is a very low energy diet (VLED) in which energy and carbohydrates are reduced to a very low level causing the body to convert fat stores into useable glucose via ketosis. It is formulated as a complete meal replacement to meet the daily requirements for all vitamins and mineralsi, but as dietitians we know that the nutrition requirements for an 80kg woman are very different to a 160kg man. So, to assist clients to meet their nutritional requirements, it’s essential that we tailor our prescription to suit the individual’s needs. One of the key nutrients to review is proteinii.

So, how can you ensure that your clients meet their protein requirements during the Intensive Level of the OPTIFAST VLCD Program?

  1. Calculate their protein requirements
    Individual protein requirements should be calculated using a patient’s Adjusted Ideal Body Weight (Adj IBW*). Most healthy patients require 0.75-1g protein/kg Adj IBW whilst losing weight using a VLED.
  2. Look for reasons a client may need higher or lower protein requirements
    In some cases, such as individuals with higher baseline lean muscle mass, or certain medical conditions may require higher than average protein requirements. Assess the patient and their risk of losing disproportionate muscle mass and if required, use a higher rate of protein to calculate their requirements.
  3. Consume additional protein on top of the 3 prescribed OPTIFAST VLCD products
    If you have calculated that your client requires higher protein, you can try the following options for increasing protein intake:
    • Use OPTIFAST VLCD ProteinPlus
      OPTIFAST VLCD ProteinPlus can be used in place of standard OPTIFAST VLCD Products. Each OPTIFAST VLCD ProteinPlus contains 28g of protein per serve, and is a low lactose alternative to the Standard OPTIFAST VLCD Shakes.
    • Use additional OPTIFAST VLCD products
      Each OPTIFAST VLCD product contains approximately 20g of protein, which would provide 60g of protein over the day. If this is not adequate protein for your client, you may want to increase the number of products they consume. For example, if calculated that the patient requires ~100g of protein per day, an additional 2 x OPTIFAST VLCD products can be prescribed to meet their requirements. It is important to consider that additional products will increase carbohydrate load, and this could potentially jeopardise the ability to initiate and maintain a ketotic environment. Therefore, assess each client’s needs individually. Encouraging patients to have these additional VLED products as mid-meal snacks can promote a more even distribution to assist with protein and nutrient absorption, as well as satiety.
    • Use additional BENEPROTEIN
      The use of a pure protein supplement such as BENEPROTEIN can be beneficial to meet increased protein requirements without providing any additional carbohydrate. Four scoops of BENEPROTEIN provides approximately 24g of protein, and can be added to the OPTIFAST VLCD Shakes, Soups or Desserts.
    • Use high protein foods
      Lean animal based meats as well as eggs and nuts provide good sources of protein while being low in carbohydrate, and therefore can be used to provide additional protein. This can be particularly useful to increase compliance with the OPTIFAST VLCD Program, as missing out on eating ‘real’ food can be a major drawback for some people. It is important to educate clients regarding appropriate portion sizes of high-protein foods as although they don’t contain a significant amount of carbohydrates, they may still be higher in total kilojoules. Patients should aim to have approximately 65g cooked red meat, 80g cooked poultry, 100g cooked fish, 2 eggs or 30g nuts for a serve.


*Adjusted IBW is equal to [(Actual Body Weight-IBW) x 0.25] + IBW. Note 0.25 is the % excess metabolically active body weight.


[i] Queensland Health, Optifast general practitioner information sheet, 2009; Queensland government


[ii] Delbridge E & Proietto J (2006); State of the Science: VLED ( Very Low Energy Diet) for Obesity; Asia Pac J Clin Nutr;15 (Suppl):49-54