What is intermittent fasting?

Intermittent fasting is an eating plan that switches between fasting and eating on a regular schedule. Research shows that intermittent fasting is a way to manage your weight and prevent — or even reverse — some forms of disease. But how do you do it? Many diets focus on what to eat, but this plan is all about when you eat. As a weight loss approach it has been around in various forms for ages, but was highly popularized in 2012 by BBC broadcast journalist Dr. Michael Mosley’s TV documentary Eat Fast, Live Longer and book The Fast Diet, followed by journalist Kate Harrison’s book The 5:2 Diet based on her own experience, and subsequently by Dr. Jason Fung’s 2016 bestseller The Obesity Code. They all  generated a steady positive buzz as anecdotes of its effectiveness proliferated.

With intermittent fasting, you only eat during a specific time. Fasting for a certain number of hours each day or eating just one meal a couple days a week, can help your body burn fat. And scientific evidence points to some health benefits, as well.

There are several different ways to do practice the program, but they are all based on choosing regular time periods to eat and fast. For instance, you might try eating only during an eight-hour period each day and fast for the remainder. Or you might choose to eat only one meal a day two days a week. There are many different intermittent fasting schedules. These programs work by prolonging the period when your body has burned through the calories consumed during your last meal and begins burning fat.

Types of Plans

It’s important to check with your doctor before starting intermittent fasting. Once you get his or her go-ahead, the actual practice is simple. You can pick a daily approach, which restricts daily eating to one six- to eight-hour period each day. For instance, you may choose to try 16/8 fasting: eating for eight hours and fasting for 16.

Another, known as the 5:2 approach, involves eating regularly five days a week. For the other two days, you limit yourself to one 500–600 calorie meal. An example would be if you chose to eat normally on every day of the week except Mondays and Thursdays, which would be your one-meal days.

Longer periods without food, such as 24, 36, 48 and 72-hour fasting periods, are not necessarily better for you and may be dangerous. Going too long without eating might actually encourage your body to start storing more fat in response to starvation.

Benefits of the plan

Research shows that these programs do more than burn fat. When changes occur with this metabolic switch, it affects the body and brain.

There are a range of health benefits associated with the practice of intermittent fasting. These include a longer life, a leaner body and a sharper mind.

Many things happen during intermittent fasting that can protect organs against chronic diseases like type 2 diabetes, heart disease, age-related neurodegenerative disorders, even inflammatory bowel disease and many cancers.

Here are some intermittent fasting benefits research has revealed so far:

• Thinking and memory. Studies discovered that intermittent fasting boosts working memory in animals and verbal memory in adult humans.
• Heart health. Intermittent fasting improved blood pressure and resting heart rates as well as other heart-related measurements.
• Physical performance. Young men who fasted for 16 hours showed fat loss while maintaining muscle mass. Mice who were fed on alternate days showed better endurance in running.
• Diabetes and obesity. In animal studies, intermittent fasting prevented obesity. And in six brief studies, obese adult humans lost weight through intermittent fasting.
• Tissue health. In animals, intermittent fasting reduced tissue damage in surgery and improved results.

Is the process safe?

Some people try intermitting fasting for weight management, and others use the method to address chronic conditions such as irritable bowel syndrome, high cholesterol or arthritis. But this diet process isn’t for everyone.

Keep in mind that intermittent fasting may have different effects on different people. Talk to your doctor if you start experiencing unusual anxiety, headaches, nausea or other symptoms after you start intermittent fasting.

Source: Johns Hopkins Medicine