Each and every year we see new health trends pop up that are supposed to change the world. Some of these are just that – trends – destined to disappear back into obscurity. Others though, come backed by science, years of use, and loyal followers.
This year, intermittent fasting seems to be in the spotlight.
So, what exactly is it? Does it work, or will it go with those other fads once we’ve all taken it for a spin?
What is Intermittent Fasting?
Intermittent fasting involves cycling between periods of fasting and eating.
When you don’t fast, and you’re eating every few hours, your body will constantly use the incoming food energy. It may not need to burn much body fat, if any, so you may just be storing that fat. Your body may be saving it for a time when there is nothing to eat. If you’re eating all throughout the day, your body isn’t entering that fasting state until bed. This can lead to weight gain because you haven’t given your body the time to burn stored food energy.
In contrast, intermittent fasting allows the body to use its stored energy. That’s what it’s designed to do.
With fasting, during the eating periods, you eat. Of course that doesn’t mean eating as much as you possibly can – just normal portions, and healthy meals. During the fasting periods, you eat either very little or nothing at all. It’s that simple.
Research shows that it can:
- improve metabolism
- change hormone levels to facilitate weight loss
- reduce insulin resistance
- increase the brain hormone BDNF
- lower blood sugar
- aid the growth of new nerve cells
- reduce inflammation
- help clear out toxins and damaged cells
And even though I mentioned this as the “new health trend” at the beginning, fasting is actually really old. We know that our ancient ancestors didn’t eat 3 square meals a day. Sometimes they couldn’t find food and didn’t even eat one meal a day. Humans have evolved to be able to function without food for extended periods of time. In fact, fasting from time to time is actually more natural than always eating 3–4 meals per day.
Ok, so how do you do it?
The Basics on Fasting
There are several different types of intermittent fasting. The basic principle is the same – splitting up your day or week into eating and fasting periods.
These are 4 of the most popular methods. Each one has been shown to be effective, it just depends on your lifestyle and working to figuring out which one works best for you:
1. The 16/8 Method
The 16/8 method involves fasting every day for 14–16 hours and restricting your daily eating window to 8–10 hours. This usually involves skipping breakfast and restricting your daily eating period to 8 hours. So you only eat between the hours of 12 – 8pm, for example. Then you fast for the other 16 hours in between.
This is like having a true “fast” day, where you eat nothing for a 24 hour period. It could mean you eat breakfast one day, then fast until breakfast the following day, or the same, just with dinner. You do this once or twice a week.
3. Alternate Day Method
This is similar to Eat-Stop-Eat, but it ramps it up a bit. With alternate-day fasting, you fast every other day.
There are several different versions of this method. In some, on fasting days you don’t eat anything. In others, it’s sort of like the 5:2 diet (below), and you significantly reduce your calorie intake. It just depends on what works for you.
4. The 5:2 Diet
The 5:2 diet involves eating normally 5 days of the week and restricting what you eat on the other two days. This usually means limiting your calorie intake to 500–600. So Tuesday and Friday, or Monday and Wednesday, for example. These are usually divided into two small, very healthy meals.
So, you’re not technically fasting on any day – you’re just really limiting your food intake, giving your body the message that it needs to work off some of that stored energy.
**Note – with each of these methods, you can drink water, coffee, tea, and other zero-calorie beverages during the fast. These can significantly reduce the feelings of hunger felt while you’re not eating.