- Vegetarian and Keto options
- Nutritionist-made with macros and calorie counts

What is The Fast 800?
The official home of 5:2™ and intermittent fasting
A step-by-step programme that helps you lose weight fast and keep it off. With tailored meal plans, workouts and support we make it easier to get healthier.

Create sustainable habits

Feel fitter

Improve blood sugars

Lose weight

Live better and longer

Reduce risk of chronic disease
Dr Michael Mosley explains weight loss
As a science presenter and author, Dr Michael Mosley was well known for popularising intermittent fasting for better health, and making scientific research easy to understand and action. The Fast 800 team are committed to continuing his legacy and sharing his insights with our wider community. In this video, Michael shares:
- The biology behind weight loss
- How to turn your body into a fat burning machine
- His three key recommendations for losing weight safely and effectively
What does it cost?
Transform your health in 12 weeks, for only
12 Week Guided Programme
- Personalised meal plan, workouts and more
- Includes a FREE 7 day trial
- Exclusive website price
- Plus a bonus FREE month
Continue with flexible support for
per month
Monthly Graduate Membership
- Use what you have learnt in the 12 week programme
- Access all your favourite recipes, workouts, Community and more
- No lock-in contract. Cancel anytime. Exclusive website price
We've helped over 120,000 people just like you lose weight, keep it off and improve their health

After losing 30kg, I've gained so much more mobility, and my knee pain has eased up tremendously.

I lost 18kg in 3 months and have become the best version of myself.

I have lost 21kg and now I feel strong, happy and pain free!

I joined to tackle my weight loss - I didn't expect such increased energy!
How it works
Our flexible dietary approaches are designed to suit your goals and circumstances. Learn The Fast 800 way so you can tweak your approach as your needs change. It's more than a diet - it's a sustainable approach to a healthy lifestyle.
Personalise your programme
- Sign up and take our assessment
- Your programme is set with the right approach for your goals and circumstances
- Switch easily between each approach as your needs change
Lose weight and reprogramme your body
- Follow your meals and exercise plan
- Learn the science as you go
- Engage with your cohort and health coaches
- Track your progress
Learn to live a healthier life
- Incorporate The Fast 800 healthy habits into your daily routine
- Tweak your programme settings to suit you best
- Sustain your results

What to expect while following The Very Fast 800
Change doesn’t happen overnight, but in 12 weeks, a remarkable transformation is possible.
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Learn the basics of nutrition and understand metabolic rates and caloric needs
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Elevate your workout routines and enhance your exercise
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Understand your body’s unique needs and start setting achievable goals
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Begin to solidify the habits you’ve learned and prepare for a sustainable lifestyle
Try the programme for free
Sign up today and your 7-day free trial begins immediately. Week 1 of your programme will start on: Monday 17th February
How much does the programme cost?
Joining is as easy as clicking here in order to join via our website, OR making payment via the Google Play / App Store. (Search for The Fast 800!)
If you join via our website, you will pay £119 / AUD$199 / USD$149 for your initial 12 weeks’ access.
Access thereafter is at £12 / AUD$22 / USD$15 per month. This payment will renew automatically until it is cancelled. You can stop your membership at any time via your Profile page.
To take advantage of more payment options (including a monthly format) or to pay in your region’s currency, you may wish to pay via the Google Play / App Store. Simply proceed through the signup and checkout process to see pricing options.
Please note:
- All offers are ONLY available through website signups
- You can still download and use the app once you have signed up via our website
What's included in the Programme?
Our Programme teaches you the health benefits of a moderately low-carb Mediterranean-style diet, so it becomes a way of eating for life. It is based on the latest science and takes an evidence-based approach to healthy living focusing on nutrition, movement, behavioural change and sustainable lifestyle.
It includes:
- Education around science-based lifestyle best practice
- Weekly, time-saving meal plans – vegetarian and non-vegetarian – with automated shopping lists
- The Very Fast 800, The New 5:2 and The Way of Life approach plans, some with Keto options
- Exercise plans, incorporating HIIT and resistance training, designed for beginner to advanced levels as well as a library for further stretching, yoga and pilates videos
- Trackers to measure waist, weight, HbA1C, mood and sleep
- 800+ easy and delicious, nutritionist-developed recipes
- Mindfulness meditations
- Core learning content, plus access to exclusive articles
- Support tools for liaising with your usual treating doctor
- Access to a lively Community so you can chat with your fellow members and/or ask our online health coaches for support
How does the free trial work?
Your programme for weight loss and long term health starts straight away.
When you click “start now”, you’ll be asked to create an account. Once your account is set successfully, please go through the checkout process, which requires you to enter credit card details, to trigger your access to the personalisation quiz and the start of your 7-day free trial.
Your credit card will only be charged if you do not cancel prior to the end of the trial period.
Please note, once you cancel the free trial, you will lose access to your account straight away.
Who should avoid a low calorie diet or fasting?
The Fast 800 programme is not recommended for the following:
- People who are underweight and/or experiencing an eating disorder, or have a history or suspicion of an eating disorder
- Children (under 18 years old)
- Type 1 diabetics
- Pregnant women, breastfeeding mothers or anyone undergoing fertility treatment
- People who have a significant psychiatric disorder or substance abuse
- People who are under active investigation or treatment, or have a significant medical condition affecting ability to comply with diet
- People who have had a recent cardiac event, myocardial infarction or cerebrovascular accident (<3 months previously) or other heart abnormalities
- People who have had uncontrolled heart disease, uncontrolled hypertension, or kidney failure
- People who are feeling unwell, have a fever, are frail or recovering from significant surgery (<6 months ago)
- People who are on insulin. This is to avoid a potentially dangerous drop in blood sugar (hypo)
- People who are on ‘flozin’ medication (known as SGLT2 inhibitors, taken to reduce blood sugars). This is to avoid the rare complication and potentially dangerous condition called euglycaemic diabetic ketoacidosis (DKA), where despite having normal or only mildly raised ketones the medication can mask a serious complication of diabetes requiring urgent attention
Please read our medical disclaimer for additional information.
How much weight will I lose?
The DIAMOND Study performed by Oxford University and Dr Clare Bailey looked at the feasibility of using an 800 calorie, low-carb, med-style diet as a treatment for people with type 2 diabetes.
After 8 weeks the average weight loss was 9.5kg, sustained over the course of the trial.
Results also included a significant drop in blood sugars, blood pressure and the use of medication.
Can I re-start the 12-week Programme after I start?
As the Programme is guided, you are unable to pause or restart the course.
You can view content from previous weeks and you also receive a free four week trial of the monthly subscription service at the end of the 12-week Programme, to allow you to catch up on any missed content.
When does Week 1 start? Why is there "prepare" time?
Please be aware that Week 1 starts the Monday following sign-up. The time in between sign-up and Week 1 is called the Prepare period, and is designed to give you time to have a look around the Programme, start planning your shopping list and recipes, try a workout or two, and get used to how the programme runs and works.
Please ensure that you are signing up according to how much Prepare time you would like before Week 1 commences – for example, if you would like a full week of Prepare time, please sign-up on a Monday or Tuesday, and if you would like to start Week 1 right away, please sign up on a Saturday or Sunday.
If you have any issues with the start date of your programme, please get in touch via our Contact Us form.
Why 800 calories?
800 is the generally accepted number of calories used to achieve weight loss in scientific studies. Professor Roy Taylor, leading researcher into the reversal of type 2 diabetes, used 800 calories in his test group in the DiRECT Trial.
We have found that 800 calories is high enough to be manageable for most members, but low enough to trigger a range of desirable metabolic changes.
Do I have to give up coffee, smoking or alcohol?
No, you don’t have to give up any of these whilst following the Programme although, obviously, we would certainly advise everyone to stop smoking as soon as possible, irrespective of their blood sugars.
Coffee and alcohol are still allowed on the programme although the calories in both of these drinks need to be included in the daily calorie limit (noting that alcohol is highly calorific).
A pint of beer or a large glass of wine contains 180 calories, so really best avoided or kept to a minimum.
The good news is that red wine is included in the Mediterranean-Style diet, so once you finish The Very Fast 800 and The New 5:2, and move onto ‘The Way of Life’ approach you will be able to introduce alcoholic drinks back into your lifestyle (we go over this in more detail in the Programme learning content).
Black coffee and tea are fine although you will need to include any milks in your daily calorie count.
What is the 12 week weight loss plan for better health?
Your 12-week weight loss plan awaits
Starting a weight loss journey is a big step. Our 12-week weight loss programme is here for people who want clear results in an easy-to-follow way. With this 12-week weight loss plan, you get a complete guide that looks at exercise and eating right, making sure you make the most of each day.
If you’re ready to start this exciting journey, our 12-week diet plan is here to guide you.
A plan that truly works
Our 12-week weight loss programme is based on the latest science in healthy living. The foundation of our 12-week weight loss plan is a Mediterranean-style diet, intermittent fasting and calorie restriction, as required.
Personalised for every individual
Everyone’s journey to weight loss is different, and that’s why our 12-week weight loss programme is designed to fit individual needs. By merging the main ideas of weight control with a plan made just for you, we provide a 12-week weight loss plan that works for everyone and yet feels personal. What’s more, as the weeks go by, your 12-week weight loss workout plan will progress as you get fitter and stronger.
Our members often say that this personalised approach helps them to feel seen, supported, and inspired as they move forward in their 12-week weight loss journey, seeing real changes as they go.
Why opt for our comprehensive 12-week weight loss Programme?
Choosing the right time to embark on your weight loss journey can make all the difference. Our 12-week weight loss plan has been thoughtfully crafted to offer an optimal duration. With the 12-week weight loss programme, there’s ample opportunity for you to establish and reinforce healthy habits. Yet, it’s succinct enough to ensure you remain motivated and consistently observe the transformative results you crave.
A well-defined roadmap
Our 12-week diet plan paired with the 12-week weight loss workout plan provides a clear and comprehensive guide. Each stage is meticulously planned out, getting rid of any guesswork. So, with every day that passes, you’ll be confidently moving forward, certain of your next step.
Witness your transformation
The beauty of a 12-week weight loss journey is its tangible results. As you progress week by week, you’ll not only feel the difference but see a rejuvenated version of yourself emerging.
Science-backed approaches
What sets our 12-week weight loss programme apart is its foundation in scientific research. This commitment to evidence-based methods, which are also delicious and achievable, ensures you’re in reliable hands as you journey towards a healthier you.
Navigating through our 12-week weight loss Programme
As you embark on our 12-week weight loss plan, each week promises fresh challenges and notable milestones. Here’s a brief overview of your journey:
Weeks 1-4: foundation phase of the 12-week weight loss
- Unpack the foundational principles of nutrition and physical activity.
- Tune into your body’s specific requirements and lay down realistic objectives.
- Keep an eye on your starting weight loss achievements and take a moment to rejoice in those initial successes.
Weeks 5-8: intensification phase of the 12-week weight loss workout plan
- Amp up your exercise routines by incorporating more intricate workouts.
- Grasp the intricacies of weight loss science, including insights into metabolism and the role of calories.
- Stay committed to monitoring your advances and fine-tuning your objectives as you proceed.
Weeks 9-12: consolidation phase of the 12-week diet plan
- Take the time to reinforce and make permanent the beneficial habits you’ve picked up during the program.
- Prioritise the retention of your weight loss accomplishments, ensuring you don’t backtrack.
- As the 12-week weight loss phase draws to a close, gear up for a lifestyle that not only retains but enhances the positive changes you’ve achieved.
Embark on your 12-week weight loss journey now
If you’re set to dedicate yourself and to savour the benefits, our 12-week weight loss plan is ready for you. Embrace the 12-week weight loss workout plan and the 12-week diet plan, paving the way to a fitter, more healthy version of yourself.