I write this a few hours before the beginning of Yom Kippur, the Jewish Day of Atonement, which involves a 25-hour fast starting at sundown tonight at 6.08pm and ending 7pm tomorrow.
The point of the fast is to help us reflect on our past year and repent for any wrongdoings, so we can make amends and look forward to a happier, healthier and more worthy year ahead. Eating would interfere with this process of atonement and reflection, and in many ways fasting feels like a very cleansing, purifying experience.
Jews are not the only people who fast, of course. There’s the Muslim festival of Ramadan where fasting every day for a month makes one day of fasting look rather lightweight in comparison!
Religion aside, fasting has in recent years become an essential part of a healthy lifestyle. A few years ago, Michael Mosely brought us the popular 5:2 diet which helped many people lose weight and prevent chronic diseases such as diabetes.
The focus has shifted more to Time Restricted Eating (TRE) or Intermittent Fasting (IF) where people fast overnight for a minimum of 12 hours working up to 14 and 16 hours, with an ‘eating window’ of 12, 10 or 8 hours respectively. So if you were to follow the 16:8, your last meal might finish at 8pm and you wouldn’t eat until midday the following day.
Aside from effective weight loss, many people who fast achieve better hormone balance, improved gut health, greater immunity, and even a better night’s sleep. At the end of the day, when we’re not eating we’re allowing out body to carry out the essential repair and maintenance jobs that it can’t do when the digestive system is in operation.
There has been much research done on TRE and IF, and one eminent researcher in this field is Professor Valter Longo who has studied what happens to mice when they are in fasting mode. The benefits are very exciting and include reduction of visceral and abdominal fat, fatty liver disease and insulin resistance and although the studies are still confined to mice, it holds much promise for us humans!
There’s a process called autophagy associated with fasting, which literally means “self-eating”, and is the body's way of cleaning out damaged cells, in order to regenerate newer, healthier cells. This could well be the secret to a longer, healthier lifespan so think about how you can give your body a break from food and discover the benefits for yourself.
I’ve fasted on this holiest day of the Jewish calendar for over four decades and whilst it used to be confined to once a year, I now practice it daily (at least 12 hours) and feel all the better for it. “I wish you well over the fast” is a common greeting on Yom Kippur and I would like to extend it to anyone who decides to observe this ancient practice, regardless of their faith.
6 Ways to do Intermittent Fasting
A great podcast with my fave doc Dr Rangan Chatterjee, interviewing Prof Valter Longo. Eating for Longevity with Professor Valter Longo
Is Autophagy the Secret to Life Extension