14th June 2023

How to use Shakes on the 5:2 diet

The 5:2 diet is an excellent way of losing weight, keeping it off, and improving your health in many different ways. However, it can be difficult to know what you can and can’t eat on fasting days, while still getting all the right nutrition within fewer calories. Enter The Fast 800 Shakes, developed to complement fasting and the 5:2 diet. 

Designed with fasting days in mind, catering to different dietary needs, and with natural ingredients at their core, our 5:2 Shakes are a staple when attempting this intermittent fasting approach.

In this article, we explore what exactly the 5:2 diet is, its benefits, and how our Shakes can support your journey. 

What is the 5:2 diet?

The 5:2 diet is a method of intermittent fasting involving two ‘fasting’ days per week, and a no-calorie restriction, Mediterranean-style diet, with sensible portions, on the other five days. 

It was popularised by Dr Michael Mosley when he discovered the health benefits of intermittent fasting after being diagnosed with type 2 diabetes in 2012. 

How to do the 5:2 diet

The ‘5’ represents five days a week of eating a balanced, nutritional Mediterranean-style diet of the usual 2000-2500 calories a day. The ‘2’ represents two days a week of consuming 800 calories, which we refer to as fasting days. 

The benefits of following a 5:2 diet are extensive. Scientific evidence has shown us that intermittent fasting and the 5:2 approach may:

  • Improve insulin response, reducing risk of type 2 diabetes
  • Improve metabolism efficiency
  • Activate autophagy for cell regeneration
  • Improve quality of sleep
  • Maintain muscle mass during weight loss
  • Delay dementia and Alzheimer’s disease [1]
  • Reduce the risk of cancer [2]

Eating a Mediterranean-style diet will ensure you are consuming all the healthy fats, protein, fibre and vitamins and minerals your body needs, and our 5:2 shakes provide those essential nutrients in a conveniently, calorie-controlled portion. Additionally, you can follow The New 5:2 Approach on our Online Programme which can help keep you on track, provide you with exclusive exercise videos and meal plans designed by our in-house experts, and be a part of a network of other people trying the programme who have the same health goals as you.

To find out more about how to do the 5:2 diet, head here.

What are the 5:2 shakes?

The Fast 800 5:2-friendly shakes were designed with nutrition and convenience in mind. When following the 5:2 diet, it’s essential to ensure you’re consuming enough protein, fibre and healthy fats to keep you fuller for longer, and keeping up with your daily recommended nutrients.

The shakes are 200 calories per serving, and can be enjoyed on fasting and non-fasting days. On non-fasting days, the shakes can be used to add nutrition to meals, like making your breakfast more protein-rich and filling. On fasting days where your calorie intake is lower, the low-calorie 5:2 friendly shakes help to supplement your nutrient intake. Here’s some more nutritional information about our shakes:


Many of the shakes contain over a third of your recommended daily protein. Protein is key to weight loss, and essential for the growth and repair of your body tissue. Consuming 60g of protein a day provides many health benefits, and increases satiety and decreases hunger, while maintaining muscle mass and helping prevent weight regain.[3]


Fibre keeps your gut microbiome happy, and our shakes contain around a quarter of your recommended daily fibre. It consists of indigestible carbohydrates present in the cell walls of fruits, vegetables and whole grains. Fibre is digested by certain bacteria that have been suggested to prevent weight gain and various chronic illnesses, like type 2 diabetes.[4]

Vitamins and minerals

The Shakes contain 25% of your recommended daily intake of 26 vitamins and minerals per serving, including Vitamin A, Magnesium Oxide, and Vitamin B-12. These all help keep you nourished and support healthy weight loss and intermittent fasting.

How to best enjoy The Fast 800 5:2 shakes

Shakes are the ideal option for busy lives. Whether you’ve got kids running around and no time to cook, or you work in an office and need to take food in, having a nutritionally sound shake on hand to either enjoy on a fasting day or alongside a meal on a non-fasting day can be a real life-saver. Ready in 30 seconds with no cooking involved.

On non-fasting days, it’s as simple as shake, drink, fast – just add water, or your choice of dairy or non-dairy milk, and enjoy as a filling, 200-calorie meal. Or, if you’re looking for a little more, try one of the creative, free recipes on our website. From pancakes to smoothie bowls, there’s something for every taste bud! On non-fasting days, we recommend adding the shakes mix to smoothies, treats (like this delicious chocolate mug cake), or enjoying alongside meals to boost your daily nutrient intake.

Try our range of shakes flavours (with both vegetarian and vegan options, available in the UK, Australia and NZ). Or, if you’d like to learn more about the 5:2 diet, continue on to this article.


Mattson MP, Longo VD, Harvie M. Impact of intermittent fasting on health and disease processes. Ageing Res Rev. 2017 Oct;39:46-58. doi: 10.1016/j.arr.2016.10.005. Epub 2016 Oct 31. PMID: 27810402; PMCID: PMC5411330.

Harvie M, Howell A. Energy balance adiposity and breast cancer – energy restriction strategies for breast cancer prevention. Obes Rev. 2006 Feb;7(1):33-47. doi: 10.1111/j.1467-789X.2006.00207.x. PMID: 16436101.

Blom WA, et al. Effect of a high-protein breakfast on the postprandial ghrelin response. Am J Clin Nutr. 2006 Feb;83(2):211-20. doi: 10.1093/ajcn/83.2.211. PMID: 16469977.

InterAct Consortium. Dietary fibre and incidence of type 2 diabetes in eight European countries: the EPIC-InterAct Study and a meta-analysis of prospective studies. Diabetologia. 2015 Jul;58(7):1394-408. doi: 10.1007/s00125-015-3585-9. Epub 2015 May 29. PMID: 26021487; PMCID: PMC4472947.

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