Fasting is not a new phenomenon. Many faiths recommend spiritual strengthening through periods of prayer and fasting—sometimes a day, sometimes seven, sometimes more. In the early 1900s scientists used fasting to treat diseases such as diabetes, obesity and epilepsy, although much of the published research was in laboratory animals. Recently, fasting—particularly intermittent fasting—is experiencing renewed interest as a medical treatment for disease rather than medication.
What is Intermittent Fasting?
Intermittent fasting is not a diet but rather a pattern of eating. It involves periods of eating and fasting. These cycles can be done every day or even one day a month. Two of the most popular types of intermittent fast are the 5:2 fast and the time restricted feeding fast.
The 5:2 fast, also known as The 5:2 Diet or The Fast Diet, calls for eating normally five days a week and restricting calories—500 calories per day for women and 600 calories per day for men—on the other two days. These fast days do not have to be right in a row.
Time-restricted feeding calls for eating food within a narrow window of time, typically a six to eight-hour window. Then fasting the remaining 16 to 18 hours a day. For example, with an eight-hour window, food is eaten between 11 AM to 7 PM.