Understanding Intermittent Fasting
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Understanding Intermittent Fasting

Intermittent fasting is a process that resembles a timeout for your gut. This article explains the process, and how it benefits the body.

You’ve heard of the paleo, keto and low-carbohydrate diets. With the number of diet plans around these days, you would think there was no room for more. But there’s a new kid on the block - intermittent fasting.

While fasting is not new - it’s been practised for centuries, primarily for religious and spiritual reasons - this form of restricted eating has gained traction with athletes and fitness buffs only in the last several years or so. It has been promoted by bestselling books and endorsed by celebrities like Hugh Jackman and Benedict Cumberbatch. It is also said to be extremely popular among Silicon Valley’s top executives, who credit it for boosting their energy levels.

Why fast?

Intermittent fasting reportedly has many other benefits. Recent studies by Dr Valter Longo, a biochemist at the University of Southern California, on the effects of periodic fasting on rodents indicate that it could promote better blood sugar balance.

In fact, the experiment, reported The Independent, showed that, after a few months of periodic fasting - alternating seven unrestricted eating days with four restricted ones - the rodents’ pancreas actually started producing insulin again.

“The days of restricted eating gave the pancreas a break that allowed it to remove and recycle many of its cells. Then, when they started eating again, new cells that were capable of producing insulin emerged,” it elaborated.

Another study by Dr Longo involving humans with high blood sugar also showed improvements in blood sugar levels.

Other studies suggest fasting can boost the body’s defences against a range of health issues, including inflammation. Lowering the body’s inflammatory markers can help reduce the risk of developing health conditions such as type 2 diabetes, rheumatoid arthritis and multiple sclerosis.

Another benefit is improved memory and learning. Dr Mark Mattson, chief of laboratory of neurosciences at the National Institute on Aging in Baltimore, who has studied the effects of intermittent fasting on the brain in animals, found it reduces “brain inflammation”. He was quoted in Today: “Intermittent fasting improves cognition, which is learning and memory, and protects nerve cells from dysfunction and degeneration.”

Get on the plan

Given that many of these experiments have been done on animals rather than humans, not all are sold on the diet’s claims. However, those who have experienced its benefits are willing to let themselves go hungry - for specific periods.

There are variations of the plan for those who would like to jump on the bandwagon. Some encourage you to fast daily, others on alternate days and yet others on a weekly basis.

The Daily Fast

This fasting protocol by Swedish nutritionist Martin Berkhan recommends you eat all your meals within an eight-hour window. You can skip breakfast and choose to eat later in the day.

This works out to a 14- to 16-hour fast a day, where you consume nothing except noncaloric fluids. Sleeping hours are included in this time frame.

Alternate Day Fasting

You eat what you want for one day, then go on a restricted diet (fewer than 500 calories for women and 600 calories for men) the next. When you include sleeping time, the fast can last as long as 32 to 36 hours.

Eat Stop Eat

In this protocol created by Brad Pilon, author of Eat Stop Eat, you fast for 24 hours once or twice a week. Your fast should be broken by a regular-sized meal and you can maintain a regular exercise programme without any special diet recommendations for workout days.

The 5:2 Fast

On this plan, you cut your food down to onequarter of your normal calories on fasting days. That would work out to about 500 calories for women and 600 calories for men. Whether you consume the calories in one sitting or throughout the day is up to you.

On the other five days of the week, you can eat normally. On your fasting days, it is recommended that you exercise more lightly than on your non-fasting days.

Is it safe?

A firm believer in this form of eating, Dr Mattson has been skipping breakfast for 35 years. “Once you get used to it, it’s not a big deal,” he told The New York Times. “I’m not hungry at all in the morning, and this is other people’s experience as well. It’s just a matter of getting adapted to it.”

He feels that humans are well-suited for intermittent fasting given our ability to store food in our body. “From an evolutionary perspective, it’s pretty clear that our ancestors did not eat three meals a day plus snacks,” he said.

While fasting for short periods of time is probably safe for those who are healthy, this eating plan is not for everyone. If you are hypoglycaemic, diabetic or pregnant (and/or breastfeeding), avoid fasting until you have normalised your blood glucose and insulin levels, or weaned your baby.

Before embarking on a new diet, particularly one that involves fasting, you may wish to consult a doctor or get a referral to a registered dietitian.