What are Michael Mosley's intermittent fasting times?

December 2, 2025 •

2 min read

Following his popular 2012 documentary 'Eat, Fast, and Live Longer,' Dr. Michael Mosley's intermittent fasting methods gained widespread attention, offering a flexible route to weight loss and improved health. So, what are Michael Mosley's intermittent fasting times and how do they work within the Fast 800 approach for weight management and metabolic health?

Quick Summary

This article explains the core intermittent fasting principles advocated by Dr. Michael Mosley, detailing the evolution of the 5:2 diet and various daily time-restricted eating windows.

Key Points

Fast 800: This diet involves a rapid weight loss phase of consuming 800 calories every day for up to 12 weeks.
New 5:2 Diet: A sustainable approach where you eat 800 calories on two non-consecutive days each week and normally for the rest.
Time-Restricted Eating (TRE): Involves daily fasting windows, with Mosley preferring the 14:10 method (14-hour fast, 10-hour eating window) for sustainability.
Flexible Approach: Mosley’s programs offer flexibility, allowing adjustments to fit individual lifestyles and goals.
Mediterranean-Style Eating: All of his methods are paired with a moderately low-carb, Mediterranean diet emphasizing whole foods, healthy fats, and protein.
Consult a Doctor: It is essential to seek professional medical advice before starting any of these diets.

A Guide to Dr. Michael Mosley’s Fasting Methods

Dr. Michael Mosley popularized intermittent fasting through books like The FastDiet and The Fast 800. His approach encompasses various methods aimed at improving metabolic health and aiding weight loss. Understanding the different timetables is key to finding a suitable plan.

The Evolving 5:2 Diet

The 5:2 diet, a well-known Mosley plan, has been updated since its initial launch. The original version (2013) involved calorie restriction to 500-600 calories on two days. The updated 'New 5:2' recommends 800 calories on two non-consecutive fasting days per week, combined with a Mediterranean-style diet on other days, finding 800 calories more sustainable.

The Fast 800: Rapid Weight Loss

The Fast 800 is a more intensive, short-term plan (up to 12 weeks) for faster weight loss. This phase involves eating 800 calories daily, focusing on low-carb, Mediterranean-style meals. Afterward, people often transition to the New 5:2.

Time-Restricted Eating (TRE): Daily Fasting Windows

Mosley also supports time-restricted eating, with daily fasting periods. He suggests starting with 12:12 (12-hour eating window, 12-hour fast) and progressing to 14:10 (14-hour fast, 10-hour eating window), which he finds sustainable long-term. While 16:8 is another option (16-hour fast, 8-hour eating window), Mosley considers 14:10 more sustainable for most.

Comparing Michael Mosley’s Intermittent Fasting Times


Method	Calorie Intake	Fasting Duration	Sustainability	Suitability	Notes
Fast 800 (Rapid Phase)	800 calories/day	24-hour calorie restriction	Short-term (up to 12 weeks)	For those with significant weight to lose; requires commitment	Not for long-term; often combined with TRE
New 5:2 Diet	800 calories (x2 days/week)	Two non-consecutive days/week	Long-term	Gradual, steady weight loss and weight management	Combines calorie restriction with flexibility
TRE (14:10)	No calorie counting	14-hour fast, 10-hour eating window	Very Long-term	Metabolic health improvements, sustainable for most	Daily consistency; recommended by Mosley for the long haul

The Importance of the Mediterranean Diet

Across his plans, Dr. Mosley highlights the importance of a nutritious, Mediterranean-style diet. This diet emphasizes whole foods, healthy fats, lean protein, and vegetables.

Conclusion

Dr. Michael Mosley's methods offer various intermittent fasting times, from the New 5:2 to TRE, emphasizing combination with a Mediterranean diet. Choose a method suited to your lifestyle and always consult a healthcare professional before starting. More information is available on {Link: The Fast 800 website https://thefast800.com/}.

Frequently Asked Questions

The original 5:2 diet required women to consume 500 calories and men 600 calories on fasting days. The new, updated version has a more forgiving target of 800 calories for both men and women on fasting days, as Mosley found this to be more sustainable.

Time-restricted eating, or TRE, involves reducing the window in which you eat each day. Dr. Mosley recommends starting with a 12:12 pattern and progressing to a 14:10 window, which he considers a highly sustainable approach for long-term benefits.

The rapid weight loss phase of the Fast 800, which involves consuming 800 calories per day, is recommended for a maximum of 12 weeks or until you reach a healthy BMI.

Yes, Mosley and The Fast 800 program encourage combining TRE with the 5:2 diet for maximum health benefits. For example, on your 800-calorie days, you can choose to eat your meals within a compressed eating window like 10 hours.

Mosley's methods emphasize a moderately low-carb, Mediterranean-style diet. This means focusing on whole foods, lean protein, vegetables, and healthy fats, especially on fasting days to promote satiety and metabolic health.

No, while 16:8 is a popular intermittent fasting method, Dr. Mosley has stated it can be 'pretty tough' for long-term adherence. He often advocates for the more sustainable 14:10 method as a long-term approach.

You can choose any two non-consecutive days of the week that fit your schedule. Having at least one normal eating day between fast days can make the approach easier to manage.