Michael Mosley's Dietary Legacy: The Fast 800 Approach
The late Dr Michael Mosley, a beloved figure in British wellness broadcasting, achieved remarkable personal health transformations through his advocacy of specific dietary patterns. Before his tragic passing in 2024, Mosley established himself as a passionate proponent of intermittent fasting, particularly through what became known as the Fast 800 or 5:2 diet.
Personal Success with the Fast 800 Regimen
Dr Mosley adopted this dietary approach with clear objectives: to reduce his blood pressure, shed excess weight, and address his type 2 diabetes. The results were striking. Over a 12-week period, he lost nearly 20 pounds (9kg) and successfully put his diabetes into remission, demonstrating the potential effectiveness of this method for metabolic health improvement.
The Fast 800 diet, as shared on the official Instagram account, explains: "Our co-founder Dr Michael Mosley is best known for creating the 5:2 diet, with which he lost nearly 20 pounds (9kg) in 12 weeks and reversed his diabetes."
How the 5:2 Diet Works
The dietary protocol involves:
- Consuming approximately 800 calories on two selected days each week
- Eating normally without calorie restrictions on the remaining five days
- Following Mediterranean-style eating patterns with sensible portion sizes
Dr Mosley himself explained the appeal of this approach: "Since you are only fasting for two days of your choice each week, and eating normally on the other five days, there is always something new and tasty on the near horizon. In short, it's easy to comply with a regime that only asks you to restrict your calorie intake occasionally."
He emphasised that while weight loss occurs, the primary goal is long-term health improvement, with weight reduction being a beneficial side effect of the metabolic recalibration.
Expert Insights on Intermittent Fasting
Niamh Hennessy, lead dietician at Cromwell Hospital, provides professional perspective on why intermittent fasting has gained such popularity since Dr Mosley brought it to public attention.
"The idea behind intermittent fasting is that it gives your body a break from digesting food," Hennessy explains. "This can potentially lead you to have fewer calories than if you were eating more regularly. Also, eating less often can have positive effects on your blood sugar levels which can be useful if you have prediabetes or type 2 diabetes."
Potential Health Benefits Beyond Weight Loss
Hennessy highlights several mechanisms through which intermittent fasting may benefit health:
- Calorie reduction through structured eating windows
- Blood sugar regulation beneficial for metabolic conditions
- Potential triggering of autophagy - the body's process of removing damaged cells
"There is some evidence to show that autophagy can reduce your risk of cancer and other chronic diseases, but more evidence is needed," Hennessy notes, providing balanced scientific perspective.
Research Evidence and Considerations
Current research supports certain aspects of intermittent fasting while acknowledging areas requiring further investigation:
- A 2016 review found no evidence of harm from intermittent fasting regimens
- 11 out of 13 reviews examined showed weight loss outcomes
- Three additional studies demonstrated reductions in glucose and insulin levels
- Modified alternate day fasting showed weight reduction benefits
However, the research also indicates that intermittent fasting doesn't necessarily produce superior weight loss compared to continuous calorie restriction, suggesting individual preference and adherence may be key factors.
Practical Considerations and Cautions
Hennessy offers important practical advice for those considering intermittent fasting:
"For some people, intermittent fasting can lead to overeating. This is because when you go without eating for a while, your body makes more of the hunger hormone ghrelin. This can lead you to eat lots when you break your fast. So, eating healthily and being aware of how many calories you have is still important if you choose to try IF."
She emphasises that while current evidence suggests safety for most adults, individual consultation with healthcare professionals remains crucial, particularly for those with existing health conditions or specific dietary requirements.
The dietary approach championed by Dr Mosley continues to influence public health conversations, offering a structured method that many find sustainable for long-term wellness goals while providing metabolic benefits that extend beyond simple weight management.
