If you haven’t seen the documentary ‘Eat, Fast and Live Longer’ yet it’s well worth a watch to get a better understanding of, not just the weight loss benefits, but the amazing health benefits of intermittent fasting.
In this documentary a health journalist, Dr Michael Mosley decides he wants to stay younger and physically active for longer and goes on a quest to find a way to stop the processes of ageing.
He meets a 101 year old marathon runner (video clip below) who has, not by choice but from living in a poor country, been eating a low calorie diet for most of his life which inadvertently extended his life and allowed him to stay active. He summed it up perfectly by saying “In poor countries people die of starvation, in rich countries they die of overeating.”
Mosley investigates further by travelling to the United States and meets a variety of scientists to see what the latest research shows.
The ‘Calorie Restriction with Optimal Nutrition’ Lifestyle:
He meets a ‘CRONie’ (someone who follows the CRON-diet which stands for Calorie Restriction with Optimal Nutrition) called Joe who was the same age as him but has spent the last ten years restricting his calories to 1900 calories a day compared to Dr Mosley’s estimated 2300 a day.
Joe had next to no body fat and extremely low triglyceride and HDL levels that Mosley who was surprised to be told that also he looks slim, his body was actually 30% fat. He was also told he had a high level of abdominal fat which is a risk factor for diabetes and cancer and age related diseases.
Joe showed no signs at all of developing any age related diseases and had next to no risk of heart disease or stroke.
Mosely decided he couldn’t bring himself to maintain a calorie restricted diet like Joe’s so looked for an alternative.
The Importance of Insulin-like growth factor 1 in Cell Ageing:
He meets Dr Valdo, a gerontologist who show’s him two mice in the lab. One was feed a intermittent fasting diet and the other was fed normally.
The non-iFasting mouse was far bigger than the fasting mouse and had a much shorter life expectancy.
Dr Valdo explained that a hormone called IGF1 (Insulin-like growth factor 1) is responsible for cell damage and ageing and that it’s production can be ‘switched off’ when we fast intermittently resulting in better health and a longer lifespan.
Mosley then did a 3 1/2 day fast and all of these risk markers decreased as well as his blood glucose levels. He also stopped producing as much IGF1 so his cells went into ‘repair mode’.
He decided he couldn’t bring himself to fast for that length of time every 1-2 months so needed to find another alternative.
Alternate Day Fasting:
He then met another gerontologist Dr Krista Varady (pictured below with Dr Mosley) and looked at Alternate Day Fasting (ADF) where you would eat 25% of your daily calorie needs as one meal at lunchtime and then ate whatever you like (including McDonalds!) the next day on alternating days.
She explained that most people on this fasting schedule 10-25% more food than usual the next day but it doesn’t counteract the deficit of calories from the fasting days!
The 5:2 Diet:
Mosley admitted that, although it sounded much easier than the other methods, it was highly unlikely he would be able to stick to ADF forever so followed a suggestion from neurologist Professor Mark Mattson to fast for 2 days a week and eat normally for the other 5 (a method that became known as the 5:2 Diet).
He then trialled the 5:2 Diet for 5 weeks. He admits that his fasting days ended up being “scattered around a bit” over a five weeks but managed to do his two days every week.
The results showed that he had halved the production of IGF-1, his blood glucose dropped dramatically and so did his cholesterol.
What Does this Mean?
These are all very impressive results from a health point of view however from a weight loss point of view it’s hard to say how successful it’ll be it will be for everyone. Dr Mosley was slimmer than your average person to begin with and admitted that he didn’t weigh himself before and after the trial but had to “tighten his belt a couple of notches” by the end which indicated he had lost weight.
To date there hasn’t been any research on the 5:2 diet so Dr Mosley’s experience cannot be an indicator of how it will affect everyone.
Many other people have had great success with it but there are so many factors involved such as age, level of insulin resistance, abdominal fat, gender and history of disordered eating that it makes sense to know about and try the other intermittent fasting methods before you pick the right method for you.
Have you seen this documentary? What did you think?