While some people mistake fasting with starvation, intermittent fasting is actually about alternating periods of eating with periods of fasting. The difference with starvation is that you voluntarily control the time when you eat. You usually get an eating window which is a period of time during the day when you are allowed to eat, which is followed by a period of time where no consumption of food is admissible.
The intermittent fasting craze started a few years ago with some celebrities like Hugh Jackman and Kourtney Kardashian swearing by it as a weight-loss solution. This is a legitimate option to meet your healthy lifestyle goals, according to Mark Mattson, a neuroscientist with Johns Hopkins Medicine in Baltimore, who wrote a review in the December issue of New England Journal of Medicine. "The state of the science on intermittent fasting has evolved to the point that it can now be considered as one approach, with exercise and healthy food, to improving and maintaining health as a lifestyle approach," he claimed.
If you are new to intermittent fasting, you should hydrate with water before, during, and after the fast. You should also avoid processed and unhealthy foods before and after fasting. For best results, prepare healthy meals for your first meal after the fast to avoid binging on junk food.
There are many ways to do intermittent fasting:
Circadian rhythm
During this method you fast for 13 hours and have an 11-hour feeding window. It starts at sunset and ends in the morning. This fast is based on the research of scientist Dr. Satchin Panda, and it mimics the body's natural clock.
16:8 method
The 16:8 method was popularized by Hugh Jackman as an easy and quick way to lose weight. This is a very popular fasting method where you restrict your daily eating window to 8 hours a day, and you fast for 16 hours. During that eating window, you can fit as many meals as you can, as long as you remember that for best results, you should be eating healthy and less caloric meals. It simply won't work if you eat large amounts of junk food or great amounts of calories. To accomplish this method, you can either skip breakfast or dinner.
During the fasting period, you are only allowed to drink water, black coffee and tea with no milk.
18:6 Intermittent Fast
This is an 18-hour fast with a 6-hour feeding window. Although it is similar to the 16:8 method, the couple of extra hours help your liver get rid of more glycogen while allowing your body to use ketones for fuel. It can also activate autophagy which rids the body of damaged cells.
20:4 Method
Although this is one of the most effective fasting methods for weight loss, it is recommended to switch to this fast once you are a seasoned faster. This is one of the best ways to lose weight quickly as it boosts ketone production. This restrictive type of fast that only allows you to eat during 4 hours per day has moderate autophagy benefits and also helps your mind stay alert.
36 Hour Fast
This challenging one-off fast that allegedly helps reset the metabolism and promote cellular cleansing. Also known as the "Monk Fast" for being restrictive, it is not recommended to do it more than once a week. It might also be a good way to kick-off your diet.
Alternate-Day Fasting
Also known as the "caveman diet" ADF is basically an ongoing 36-hour fast where you alternate a 36-hour fast with a 12-hour feeding window. Given how restrictive it is, new research has examined its health impacts.
Dr. Elizabeth Lowden, a bariatric endocrinologist at the Northwestern Medicine Metabolic Health and Surgical Weight Loss Center at Delnor Hospital in Illinois, explained this method to Healthline. "Alternate-day fasting tends to include both regular food intake alternating with full fasting, meaning no food intake at all, or a significantly reduced intake of about 500 calories."
Some of the potential benefits of ADF include weight loss, increased ketone bodies, lowered cholesterol levels
According to the NHS website, "it's really important not to use an extreme diet if you have a long-term illness, or if you have an eating disorder or a previous history of eating disorders."