We fast without thinking about it when we sleep through the night, but imagine if fasting for extended periods during the day could change our lives for the better? In recent years, intermittent fasting has moved from the fringes into the limelight. Some consider the word fast to have negative connotations and instead call it time-restricted eating – whatever you decide to call it, intermittent fasting is making its way into public consciousness and gaining popularity.
So, what are the benefits of intermittent fasting, and is it as healthy as fans claim? Let’s take a look.
What is intermittent fasting?
Intermittent fasting fundamentally comes down to strict periods of fasting – aka going without food and drinks that contain calories – set against periods of food consumption.
Like with any popular health trend, there are both enthusiasts and critics. And although intermittent fasting may sound like a diet, technically it isn't as you don't need to cut out any specific foods. Instead, intermittent fasting is considered an eating protocol – focused on the time window you spend eating rather than the amount or type of food you eat.
There are many ways to tackle intermittent fasting, but the at the root of all of the different approaches is to try and eat all of your food for the day within a specified time frame (we'll get into the specific protocols later) instead of grazing throughout the day and night.
Fasting may sound like a challenging way to approach eating. After all, some of us have been conditioned to believe that eating five or six small meals a day is healthy. Or perhaps you've had it drummed into you that breakfast is the most important meal of the day. To some, skipping breakfast feels like a downright crime!
The reality is that people have been fasting well before it became the 'it' trend, whether for religious purposes, out of obligation or for warding off illness. Nowadays, people fast for reasons ranging from weight loss to mental clarity – but how effective is it really?
Intermittent fasting benefits
Followers of intermittent fasting tout a wide range of reasons why they choose to intermittent fast. It's time to look at some of the top benefits of intermittent fasting, and see if it's up your alley or not.
Aids in weight loss
For some, intermittent fasting is an effective tool for weight loss. Because the time you spend eating is more limited, you may naturally consume less food and therefore fewer calories. At the same time, intermittent fasting can lead to hormonal changes that make weight loss easier, including increasing growth hormone levels in the body and managing insulin.
May reduce the risk of diseases
Intermittent fasting can reduce insulin resistance in the body, making it helpful in preventing type II diabetes. It's also showing promise in terms of lowering so-called "bad" cholesterol, which can cause heart disease. Although more human studies are needed when examining the correlation between fasting and disease, results so far have been exciting.
Once you get used to intermittent fasting, you may end up enjoying the simplicity of a reduced eating window. It requires less planning and meal prep, and could even save you a pretty penny or two!
May increase energy and focus
Many fans of intermittent fasting claim that their concentration and energy levels improve during a fast. The reason? It could be due to the body's release of norepinephrine, a hormone similar to adrenaline that enhances cognition and may also burn fat.
There are many other intermittent fasting benefits on top of all that, but every person is different and may experience different effects. As such, always consult with a primary care physician or medical professional before embarking on any new diet or lifestyle change.
How to intermittent fast
If you're interested in all the different ways to intermittent fast, here are some of the most common styles and methods:
The 16/8 protocol is one of the most common methods of intermittent fasting. Also known as the Leangains method, Swedish fitness coach Martin Berkhan popularized this form of intermittent fasting. This method is popular because it can be adapted to busy schedules.
Instead of eating and snacking from the time you wake up in the morning until it's bedtime, with the 16/8 protocol you fast for 16 hours and consume all of your food within an eight-hour window. What makes this style of intermittent fasting so common is that it's very flexible – it's up to you to decide when your eight-hour eating window begins and ends.
Let's say, for example, that you're not a big fan of breakfast. In that case, you could skip your morning meal and break your fast at around 1 pm; then make lunch your first meal and eat as you usually would and finish by 9 pm. Begin your fast, then repeat.
If you can't imagine life without your morning oats, change your eating window to one that suits your schedule or natural eating rhythm – you could skip dinner instead and begin your fast at 5 pm and end it (with breakfast) at 9 am.
This fast follows the same logic as the 16/8; the only difference is that your eating window is only four hours rather than eight. As an example, you could start eating at 5 pm and finish at 9 pm, then fast during the other 20 hours. This is a pretty intense fast, and not for those of you new to fasting, so try not to jump into a fast like this quickly. It's a good idea to work your way up slowly by starting with the 16/8 method and adding on the extra hours of fasting over time.
Another one of the most popular intermittent fasting methods is the 5/2 Diet, also known as the Fast Diet. This one differs from 16/8 and 20/4 because the fasting (other than sleep, of course) doesn't need to happen every day. Instead, while following 5/2, you would eat as you usually would for five days, then on the remaining two "fasting" days, you would restrict your diet to just 500 - 600 calories.
It doesn't matter when you have your two low-calorie days, as long as you don't do them back-to-back. Some people find this approach easier because it offers them the possibility to eat regularly for most of the week, while others find it more difficult. It's all about finding something that works for you and your lifestyle.
Is intermittent fasting healthy?
Intermittent fasting is healthy only if you make sure to eat nutritious food during your eating window. If you fast for hours only to binge on junk food during your feeding time, then you won't get the benefits of intermittent fasting that people go on about.
It's also important to note: If you have a history of disordered eating, are underweight, pregnant, breastfeeding or on prescription medications, be sure to consult your doctor or a specialist before trying intermittent fasting, as it could be dangerous for your situation.
But Why Intermittent Fasting and Keto?
Intermittent fasting and keto affect the metabolism in the same way (i.e. both lead to ketosis), so why not just use one or the other? Well, for practical reasons. Intermittent fasting is difficult when you're not on a ketogenic diet and the ketogenic diet gets a boost with intermittent fasting.
Keto dieters who are well into ketosis already have low blood glucose and insulin levels and are in full fat-burning more. They also have reduced appetite thanks to the satiating effects of a keto diet as well as elevated ketone levels. All this means that they'll experience less hunger and no sugar crashes when fasting.
If you're on a standard high-carb diet, not eating for long periods of time will cause sharp drops in blood glucose levels and a rise in hunger hormones. This can have you feeling shaky, weak, and irritable. Not to mention that it's impossible to function when feeling hungry all day.
And as for the benefits of intermittent fasting on ketosis – it works. Intermittent fasting helps raise ketone levels by keeping insulin levels low. Elevated ketones mean your body is burning fat for fuel. Furthermore, intermittent fasting allows you to reduce your calories even more while on a keto diet because you spend less time eating.