- Vegetarian and Keto options
- Nutritionist-made with macros and calorie counts
A personal trainer, nutritionist and member-only app, ready when you are.
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Developed by Dr Michael Mosley and a team of nutritionists and doctors following the latest science, our step-by-step programme helps you lose weight fast and keep it off. With tailored meal plans, workouts and support we make it easier to get healthier and activate your body’s ability to burn fat.
We've helped over 100,000 people just like you lose weight, keep it off and improve their health
Calli lost 21kg and found freedom from all medication.
Jill lost 30kg and found better mobility with less knee pain.
Garry lost 31kg and found out how much he loves running!
Jan lost 18kg and started swimming again.
Jennifer lost 18kg, as well as her headaches and asthma. She found her blood pressure in the normal range.
Pavel lost 63kg and put his pre-diabetes into remission.
Helen lost 21kg, as well as her pain and thyroid issues. She found more energy!
12 week programme
( – select your currency when you sign up)
This gives you access to the 12 week programme plus one extra month of membership to The Fast 800. After that, your ongoing monthly membership is . You can cancel this monthly membership at any time. *This price structure is only available via the website.
Start your personalised programme now with your first 7 days absolutely free
Sign up today and your free trial begins immediately. Week 1 of your programme will start on:
Monday 26th FebruaryJoin today!
Our low-carbohydrate, Mediterranean-style meals are nutritionally balanced to keep you fuller for longer and promote rapid fat burning. They are easy to prepare and of course, taste great!
Your body mainly runs on two types of fuel: sugar (in the form of glucose) and fat. When it uses glucose, fat is stored in the body.
When you have more glucose than your body needs for energy, it eventually gets stored as body fat. This commonly happens when someone eats a high-carbohydrate (sugar & starch) diet.
When you eat a low-carb diet, your body has less glucose to run on. So, it starts to use your fat stores instead. You can fast-track this process by intermittent fasting.
The Fast 800 Programme will teach you how to combine delicious food with intermittent fasting so you can burn through excess fat stores and return your body to health.
Click on the timestamps to see how the typical body responds over 12 weeks to our most popular approach
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You may see a stabilisation
Less hungry, with more energy and motivation
Potential weight loss
The body is likely in ketosis, and is adapting well to using fat as fuel. Motivation to continue will increase as the scales start to shift. Weight loss will differ from person to person.
You will see a stabilisation
You may feel more positive
Less hungry with more energy and motivation
Metabolic health is improving. Your body is using energy more effectively and is able to switch between glucose and fat for fuel. Weight loss may stall for a few weeks, which is normal as the body continues to adjust.
You should see a stabilisation
Sleeping well. Sustained energy and motivation
Sustainable weight loss
You're in a good routine and have sustained energy for exercise. Your metabolism switches between glucose and fat burning easily. You may see a return to stable weekly loss of around 1lb/0.5kg a week.
You should see a stabilisation
Strong and motivated to continue with your health goals
Overall, significant weight reduction
Your body can now use the energy from your food efficiently. Insulin sensitivity has improved, meaning less insulin is required to control blood sugar levels. Your health is on track and you can feel the difference!
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Based on data collected from 23,000 members
6kg 3 mths
Members following the online programme for at least three months lost an average of 6kg
7.3kg BMI > 30
Members who started with obesity (BMI >30) lost an average of 7.3kg after three months
Members with a BMI ≥ 30 were likely to sustain an average weight loss of 8.7kg at 12 months.
Members with a BMI ≥ 30 saw a significant reduction (on average 4.7cm after 12 weeks) in waist circumference, which is linked to significant health benefits.
Of members with pre-diabetes with a BMI ≥ 30, 61% had blood sugars returned to normal after 12 weeks.
The average decrease in HbA1c values within the diabetic member group was 28 mmol/mol, which is clinically significant.
Browse through our most commonly asked questions
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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.
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.
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.
The Fast 800 programme is not recommended for the following:
Please read our medical disclaimer for additional information.
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.
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.
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.
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.
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.
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