What is religious fasting, how does it affect health?

Whether it involves completely abstaining from food and drink or a lighter, lower-calorie form of eating, fasting is practised in various religions and philosophies across the world, including Christianity, Islam, Judaism, Buddhism, Hinduism, Taoism and Jainism.

Fasting has been used therapeutically since at least the 5th century bce, when Greek physician Hippocrates recommended abstinence from food to some patient Source: Getty / Getty Images/mustafagull