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What is The Fast 800?

The official home of 5:2 and intermittent fasting

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.

Create sustainable habits

Feel fitter

Improve blood sugars

Lose weight

Live better and longer

Reduce risk of chronic disease

What our members say

We've helped over 100,000 people just like you lose weight, keep it off and improve their health

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What's included

Personalised meal plans to suit your goals

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

200 guided workouts, no equipment required

  • Low impact beginner to advanced fitness
  • Resistance, cardio, yoga and pilates

800+ simple and tasty recipes

  • Automated shopping lists
  • Satisfying portions and a range of global cuisines

Real support, as you need it

  • Member-only Health Coach support
  • Be part of an interactive cohort

Member-only app for ultimate convenience

  • Weight loss tools in the palm of your hand
  • Use your programme any time, anywhere

Behaviour change course and mindfulness

  • Science-backed support to make new habits stick
  • 40+ guided mindfulness videos

What does it cost?*

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.

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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 15th July

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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

With delicious meals to enjoy, not endure

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!

As seen in

Dr Michael Mosley explains the biology behind weight loss

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The science behind The Fast 800

The biology behind weight loss

Burning energy 101

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.

The sugar problem

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.

How to burn fat

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.

What to expect while following The Very Fast 800

Click on the timestamps to see how the typical body responds over 12 weeks to our most popular approach

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Blood sugar

You may see a stabilisation

How you feel

Less hungry, with more energy and motivation

Weight loss

Potential weight loss

Body fuel


What's happening?

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.

Blood sugar

You will see a stabilisation

How you feel

You may feel more positive

Weight loss

Less hungry with more energy and motivation

Body fuel


What's happening?

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.

Blood sugar

You should see a stabilisation

How you feel

Sleeping well. Sustained energy and motivation

Weight loss

Sustainable weight loss

Body fuel


What's happening?

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.

Blood sugar

You should see a stabilisation

How you feel

Strong and motivated to continue with your health goals

Weight loss

Overall, significant weight reduction

Body fuel


What's happening?

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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The Fast 800: Australia’s Leading Online Weight Loss Program

The Fast 800 is Australia’s leading choice for achieving fast weight loss with a scientifically-backed approach. Our comprehensive online weight loss programs are tailored to fit your lifestyle, offering you the guidance and support you need to reach your health goals. Whether you’re seeking a structured weight loss meal plan in Australia or flexible online options, The Fast 800 has you covered.

Step into a world of health and transformation with The Fast 800, Australia’s leading online weight loss program. Embrace the journey towards a healthier, more vibrant you with our customised meal plans and comprehensive support. We’re here to guide you every step of the way, ensuring your path to weight loss is not only successful but also enjoyable and sustainable.

Our Program

  • Customised Weight Loss Meal Plans: Dive into our personalised weight loss meal plans, specifically designed for fast weight loss in Australia. Our plans are crafted to suit your individual dietary needs and preferences, ensuring you enjoy delicious, nutritious meals while on your weight loss journey.
  • Comprehensive Online Weight Loss Programs: Experience the convenience and effectiveness of our online weight loss programs. With The Fast 800, you have access to expert advice, community support, and a wealth of resources at your fingertips, all accessible from the comfort of your home.
  • Support Every Step of the Way: Our program is more than just a diet plan; it’s a holistic approach to weight loss. From nutritional guidance to fitness tips, we provide comprehensive support to help you every step of the way.

Join The Fast 800 Community

Embrace a healthier lifestyle with The Fast 800’s online weight loss programs. Join our community of like-minded individuals in Australia and start your journey towards effective and sustainable weight loss today.

Get Started With The Leading Weight Loss Meal Plan In Australia

Embark on a health journey with The Fast 800, where your aspirations for fast and sustainable weight loss become a reality. Our tailored online weight loss programs and meal plans are specifically designed for the Australian lifestyle, offering you the perfect blend of convenience, support, and expertise. Join our thriving community and take the first step towards a healthier, more vibrant you. With The Fast 800, a successful and rewarding weight loss journey is more than a possibility and we’ve seen thousands of people achieve their weight loss and health goals.. Start your journey today and experience the change you’ve always desired. Your path to wellness begins here, with The Fast 800.

12 week Weight Loss Program: A Transformative Journey

Embarking on a weight loss journey can be both exciting and daunting. The key to success often lies in a well-structured, time-bound approach that promises measurable results. Our 12 week weight loss program does just that. It offers a meticulously planned path that ensures each day contributes to your overarching goal.

Whether you’re a newbie or someone who’s tried other methods in the past, this transformative journey is crafted to make every step count, ensuring you see the changes you desire by the end of the 12 weeks.

Your 12 week Weight Loss Challenge Transformation

Embarking on a weight loss journey is always a pivotal decision. But what if you could witness a significant transformation in just 12 weeks? Our 12 week weight loss program is designed for those who seek noticeable changes in a structured and efficient manner. With this 12 week weight loss challenge, you are provided with a comprehensive plan that targets both physical and nutritional aspects, ensuring that you get the most out of every single day.

The beauty of a 12 week weight loss plan is that it is neither too short to see results nor too long to maintain commitment. As the weeks progress, you’ll find yourself more invested, not just in shedding pounds, but also in adopting a lifestyle that prioritises health and well-being. So, if you’re keen on setting forth on a journey to better health, this 12 week weight loss program holds the key. Let’s explore what it’s all about.

A Proven Strategy for Measurable Change

The concept behind our12 week weight loss challenge is grounded in proven strategies and methodologies. While many weight loss avenues promise quick fixes or immediate results, a 12 week weight loss approach allows the body and mind ample time to adapt, learn, and transform. With each week, participants not only shed pounds but also garner a deeper understanding of their body’s needs, strengths, and potential. This holistic approach ensures that weight loss is not just a fleeting phase but a stepping stone to lasting health and wellness.

Tailored to Individual Needs

Everybody’s weight loss journey is unique, and our 12 week weight loss program respects that individuality. By combining the core principles of weight management with customisation based on one’s specific needs, we offer a path that is both universally effective and personally tailored.

This balance ensures that participants don’t feel lost in a one-size-fits-all plan. Instead, they feel understood, supported, and motivated as they work through their 12 week weight loss journey, witnessing tangible results along the way.

Why Choose a 12 week Weight Loss Program?

When it comes to shedding those extra pounds, timing is crucial. A 12 week weight loss challenge strikes a perfect balance. It’s long enough to cultivate healthy habits, yet short enough to stay motivated and see results.

  • Structured Plan: Our program gives you a detailed roadmap. You won’t wander, wondering what to do next.
  • Quick Results: 12 weeks is all it takes to see a transformed you.
  • Scientific Approach: Every strategy implemented is backed by science, ensuring effectiveness and safety.

What to Expect in Your 12 week Weight Loss Challenge

Every week in our 12 week weight loss program presents new challenges and milestones. Here’s a snapshot of what you’ll experience:

Weeks 1-4: Foundation Phase

  • Learn the basics of nutrition and exercise.
  • Understand your body’s unique needs and start setting achievable goals.
  • Monitor initial weight loss and celebrate small victories.

Weeks 5-8: Intensification Phase

  • Elevate your workout routines and introduce more advanced exercises.
  • Understand the science of weight loss, understanding metabolic rates and caloric needs.
  • Continue tracking progress and adjusting goals accordingly.

Weeks 9-12: Consolidation Phase

  • Begin to solidify the habits you’ve learned over the past two months.
  • Focus on maintaining weight loss and preventing any rebound.
  • Prepare for a post-program lifestyle to ensure sustained results.

Start Your 12 week Weight Loss Challenge Today

Change doesn’t happen overnight, but in 12 weeks, a remarkable transformation is possible. If you’re ready to commit, to put in the work, and to reap the rewards, our 12 week weight loss program awaits. Here’s to a healthier, happier you.

Typical results from The Fast 800

Based on data collected from 23,000 members

Weight loss

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

Long term sustained weight loss

Waist circumference reduction

Improved blood sugar levels

Lower HbA1c levels

Frequently Asked Questions

Browse through our most commonly asked questions

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How much does the programme cost?

What's included in the Programme?

How does the free trial work?

Who should avoid a low calorie diet or fasting?

How much weight will I lose?

Can I re-start the 12-week Programme after I start?

When does Week 1 start? Why is there "prepare" time?

Why 800 calories?

Do I have to give up coffee, smoking or alcohol?

Still got questions? Please visit our full FAQ page or contact us and we’ll get back to you!

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