Can depriving the body of sustenance connect us to God? Fasting is prominent in several major world religions, including Islam, Judaism and Buddhism. For many, it's considered a test of self-restraint and a pathway to greater wisdom; however, fasting can also become uniquely pleasurable for those who've ever attempted it. Mary Elizabeth Williams explores the intriguing effects of fasting on the brain. Of course, you can't starve yourself to nirvana; however, as she discovers, recent research affirms that regular restriction can improve cognition and even stave off some of the effects of ageing.