How To Do The Fast 800
The Fast 800 is the umbrella term for a healthy lifestyle based on scientific evidence, encompassing diet, movement and mindfulness.
It’s not just 800 calories
The goal of The Fast 800 and our online programme is to empower you with the tools and knowledge to live a healthy lifestyle long-term. As a result, there are three flexible dietary approaches that can be followed:
- The Very Fast 800
- The New 5:2
- The Way of Life
Every approach follows the principles of a moderately low-carb, Mediterranean-style diet, one of the most researched and scientifically-praised diets. These approaches are designed to suit your goals and circumstances, and you can switch between each approach as your needs change. There is likely to be an approach suitable for you, whether you’re looking to lose a lot of weight for better health, or want to eat in a way that will support healthy ageing and promote longevity.
Join our email community
Learn more about The Fast 800 approach to healthy living by receiving our free content, health tips and recipes as well as exclusive offers, delivered straight to your inbox.
Creating a long-term lifestyle
It’s not recommended to stay on The Very Fast 800 for longer than 12 weeks, but The New 5:2 and The Way of Life can be followed long-term. Doing so will see you reap a number of ongoing health benefits, including improved mood, weight management, better sleep and digestion, more energy and you’ll be reducing your risk of developing chronic diseases like type 2 diabetes and heart disease.
The Fast 800 online programme offers non-vegetarian and vegetarian meal plans for each approach, created by our in-house nutritionist. No matter the approach, your meal plan will provide you with adequate protein and fibre to help you reach your goals, with plenty of variety and flavour to keep you feeling satisfied.

The Very Fast 800 and The New 5:2 include “fasting days” of 800 calories, but to maximise the benefits of all three dietary approaches, you’re encouraged to incorporate time-restricted eating (TRE), exercise and mindfulness to round out your The Fast 800 lifestyle. The online programme guides you through implementing these into your lifestyle with educational content, videos and a comprehensive exercise plan.
Practising small habits daily – like a short mindfulness activity, a quick but effective workout and making good food choices – is the backbone of The Fast 800, designed to make healthy living sustainable.
For further information on, or to join, The Fast 800 online programme, click here.
How to transition between approaches
When you join The Fast 800 Online Programme, your personalisation questionnaire will determine the most appropriate approach for your start. From there, you’ll learn how to move through the approaches as your goals and needs change. We also provide educational content to help you make the transition away from your current approach to a new, more flexible one that will help you long-term.
Weight loss is not linear and being aware of this is important; with social events, holidays and hormones, it is likely, and completely normal, that unwanted weight will creep back on or be harder to lose at times. If this does happen and you want to shift it quickly, you can change your meal plan back to The Very Fast 800 and follow it for a short period of time (we recommend just two weeks) or follow The New 5:2 for a more gradual approach. Alternatively, you can use the approaches in planning for events, holidays or periods that might be trickier to navigate.
For example, you might choose to follow The New 5:2, but switch to The Way of Life over a holiday period. If you come back from a holiday feeling sluggish or want a kick-start back into fasting, you might do a week or two of The Very Fast 800, before transitioning back into The New 5:2 long-term. The approaches are designed to integrate seamlessly into your life.
An example journey
Everyone is different, however, here’s an idea of how a member who starts The Fast 800 with a lot of weight to lose might move between the approaches throughout their first year.
- Do up to 12 weeks of The Very Fast 800
- Transition to The New 5:2 with some TRE, continuing until they reach a healthy weight
- Switch to The Way of Life, still practising TRE but perhaps adjusting eating and fasting windows
- If weight does creep back on, transition to The New 5:2, potentially increasing their TRE fasting window, or do a short reset of two weeks on The Very Fast 800 before moving to either of the long-term approaches.
Alongside diet, this person would also do a few short sessions each of resistance exercise and high-intensity interval training weekly, and regular mindfulness activities.
Progress markers to look for:
Not all progress is reflected in the numbers on the scale. If you’re not seeing much change in your weight, look for other signs of progress:
- decreased waist as well as other body measurements;
- healthier hair, nails and skin;
- better quality sleep;
- increased energy and fewer “crashes”;
- improved fitness;
- changes in how your clothes fit;
- improved digestion;
- clarity of mind; and
- reduced cravings.
Flexibility and finding what works for you are pivotal in maintaining a long-term, sustainable lifestyle. The Fast 800 is designed to complement your life and any event, holiday or challenge that comes with it.