Intermittent fasting, simply stated, is cycling between periods of fasting and eating. It’s currently a very popular method to lose weight and improve health.

The goal of this beginner’s guide is to provide everything you need to know about intermittent fasting, in order to get started.

What is intermittent fasting?

Intermittent fasting is not a diet, it’s a pattern of eating. It’s a way of scheduling your meals so that you get the most out of them. Intermittent fasting doesn’t change what you eat, it changes when you eat.

In this respect, it’s not a diet in the conventional sense but more accurately described as an eating pattern.

Common intermittent fasting methods involve daily 16-hour fasts or fasting for 24 hours, twice per week.

Fasting has been a practice throughout human evolution. Ancient hunter-gatherers didn’t have supermarkets, refrigerators or food available year-round. Sometimes they couldn’t find anything to eat.

As a result, humans evolved to be able to function without food for extended periods of time.

In fact, fasting from time to time is more natural than always eating 3–4 (or more) meals per day.

Intermittent Fasting Methods

There are several different ways of doing intermittent fasting — all of which involve splitting the day or week into eating and fasting periods.

During the fasting periods, you eat either very little or nothing at all.

These are the most popular methods:

The 16/8 method: Also called the Leangains protocol, it involves skipping breakfast and restricting your daily eating period to 8 hours, such as 1–9 p.m. Then you fast for 16 hours in between.

Eat-Stop-Eat: This involves fasting for 24 hours, once or twice a week, for example by not eating from dinner one day until dinner the next day.

The 5:2 diet: With this methods, you consume only 500–600 calories on two non-consecutive days of the week, but eat normally the other 5 days.
By reducing your calorie intake, all of these methods should cause weight loss as long as you don’t compensate by eating much more during the eating periods.

Many people find the 16/8 method to be the simplest, most sustainable and easiest to stick to. It’s also the most popular.

How It Affects Your Cells and Hormones

When you fast, several things happen in your body on the cellular and molecular level.

For example, your body adjusts hormone levels to make stored body fat more accessible.

Your cells also initiate important repair processes and change the expression of genes.

Here are some changes that occur in your body when you fast:

Human Growth Hormone (HGH): The levels of growth hormone skyrocket, increasing as much as 5-fold. This has benefits for fat loss and muscle gain, to name a few

Insulin: Insulin sensitivity improves and levels of insulin drop dramatically. Lower insulin levels make stored body fat more accessible.

Cellular repair: When fasted, your cells initiate cellular repair processes. This includes autophagy, where cells digest and remove old and dysfunctional proteins that build up inside

Gene expression: There are changes in the function of genes related to longevity and protection against disease.

A Very Powerful Weight Loss Tool

Weight loss is the most common reason for people to try intermittent fasting .

By making you eat fewer meals, intermittent fasting can lead to an automatic reduction in calorie intake.

Additionally, intermittent fasting changes hormone levels to facilitate weight loss.

In addition to lowering insulin and increasing growth hormone levels, it increases the release of the fat burning hormone norepinephrine (noradrenaline).

Because of these changes in hormones, short-term fasting may increase your metabolic rate by 3.6–14%

By helping you eat fewer and burn more calories, intermittent fasting causes weight loss by changing both sides of the calorie equation.

Studies show that intermittent fasting can be a very powerful weight loss tool.

A 2014 review study found that this eating pattern can cause 3–8% weight loss over 3–24 weeks, which is a significant amount, compared to most weight loss studies.

According to the same study, people also lost 4–7% of their waist circumference, indicating a significant loss of harmful belly fat that builds up around your organs and causes disease.

Another study showed that intermittent fasting causes less muscle loss than the more standard method of continuous calorie restriction.

However, keep in mind that the main reason for its success is that intermittent fasting helps you eat fewer calories overall. If you binge and eat massive amounts during your eating periods, you may not lose any weight at all.

Health Benefits

These studies have shown that it can have powerful benefits for weight control and the health of your body and brain. It may even help you live longer.

Here are the main health benefits of intermittent fasting:

Weight loss: As mentioned above, intermittent fasting can help you lose weight and belly fat, without having to consciously restrict calories.

Insulin resistance: Intermittent fasting can reduce insulin resistance, lowering blood sugar by 3–6% and fasting insulin levels by 20–31%, which should protect against type 2 diabetes.

Inflammation: Some studies show reductions in markers of inflammation, a key driver of many chronic diseases.

Heart health: Intermittent fasting may reduce “bad” LDL cholesterol, blood triglycerides, inflammatory markers, blood sugar and insulin resistance — all risk factors for heart disease.

Cancer: Animal studies suggest that intermittent fasting may prevent cancer.

Brain health: Intermittent fasting increases the brain hormone BDNF and may aid the growth of new nerve cells. It may also protect against Alzheimer’s disease.

Source : Healthline

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