Unless a fast-free period has been declared, Orthodox Christians are to keep a strict fast every Wednesday and Friday.
abbamoses.com

Canon 1251 Abstinence from eating meat or another food according to the prescriptions of the conference of bishops is to be observed on Fridays throughout the year unless they are solemnities; abstinence and fast are to be observed on Ash Wednesday and on the Friday of the Passion and Death of Our Lord Jesus Christ.
http://www.catholic.org/clife/lent/abfast.php

Michael Mosley’s interesting discovery of the 5:2 diet – which at first blush looks like a much more sustainable and healthy way of keeping weight down than any other I’ve heard of – isn’t all that much of a discovery. In an age when only scientific evidence counts, though, it might help us to appreciate again the wisdom of the ancient Christian, Jewish and Islamic traditions of abstinence.

As the quotation above shows, Christianity has a long tradition of abstinence – two days a week originally. The Christian community probably inherited it from contemporary pious Jewish practice (though it was never a requirement of the Law), though they changed the days because it made sense for one fast day to be Friday, the day of the crucifixion. Islam continued to recommend abstinence on Mondays and Thursdays, probably the same days as Jewish practice.

And what is fasting / abstinence in this context? In the Christian tradition, not an absolute prohibition on food, certainly. catholic.org again: ‘The Church defines this as one meal a day, and two smaller meals which if added together would not exceed the main meal in quantity.’ And abbamoses.com agrees: ‘When fasting, we should eat simply and modestly. Monastics eat only one full meal a day on strict fast days’. That’s awfully close to the 500/600 calories suggested for the abstinence days on the 5:2 diet.

Confession time: I’ve become aware that as a bishop, you get lots of opportunities to eat very fattening food. There’s definitely more of me than there used to be. So why is it that it took an article in the Daily Telegraph (not my normal paper, you will understand) to remind me of the resources in my own tradition? I just hadn’t made the connection between what I knew as a part of church tradition, and my own life.

Of course in the faith traditions, abstinence isn’t about weight loss: that’s a phenomenon of modern times, for most of us. Much more deeply, it’s about discipline: living the best life for you, not the easiest. So, yes I am going to try to adopt the Christian pattern of abstinence. If I turn down your lovely sponge cake, please try not to be too offended. And I am (more importantly) going to try to pay more attention to the wisdom of the church’s tradition, without having to have it filtered through popular science first.