Cutting to the chase: You can Intermittent fast for as long as you want! There are many benefits to fasting that continue throughout the fasting period, as well as a few downsides which we will discuss. Typically, I won’t engage in intermittent fasting for longer than 3 months at a time, but you can safely make this routine a key part of your life for extended periods.
Fasting is an age-old practice where foods, drinks or even just select food and drinks are abstained from.
Fasting comes in a number of different forms, some examples are:
- The 5/2 method
Where you eat normally for 5 days and for the remaining 2 you minimize your intake. Roughly 500-600 calories is considered acceptable.
- Windowed fasting
Fast for a number of hours for the day and have an eating window in the remaining hours. For example, fast for 16 hours and eat within the remaining 8.
- The skip a meal method
You miss a daily meal of breakfast, lunch or dinner.
- The Warrior Diet
The idea is to only consume one meal at dinner time.
But the big question is; how long to intermittent fast for?
Currently, there is very little scientific evidence showing the benefits and side effects of fasting long term. There is however a lot of information on the pros and cons of intermittent fasting in the short term. This could shed some light onto what is possible long term, but due to the lack of scientific evidence is not proven.
There are a number of lasting benefits for the human body:
- You will eat less
Overall you will consume less food due to restricted eating windows or skipped meals.
- Possible weight loss
I say possible as this will depend on what you eat, and what else you do. Intermittent fasting is not a free pass to eat whatever you want and you’ll suddenly lose weight, a balanced diet is still required. However, fewer calories may mean a deficiency in energy, leading to possible weight loss.
- Helps to promote better cognitive function
Your brain will perform better as you will be using less of the stored energy you have for converting food into new energy.
- Allows the body to cleanse itself
Having no food to process will allow your body to spend the energy on maintenance or repair instead, pushing out toxins and flushing waste the way that it should.
Fasting side effects
There are some side effects to be wary of, especially when starting to fast:
- You will be hungry
As the body will be accustomed to receiving food at certain times, you will feel hunger when you start to miss meals. The first week of fasting can be hard, but eventually your body adjusts and the hunger pains become much less common.
- You may feel fatigued
The deficit of calories entering your body can may make you feel tired, but as your body adapts you will find this disappears.
- Your mood can change
The part of the brain that regulates your mood also regulates your appetite. During the initial process you may feel irritable due to the change.
- Can lead to dehydration
While fasting, you need to consume extra water. This is due to the body not being able to retain as much water due to the lower amounts of food entering your body. If you are drinking more water, then there is also the added side effect of needing to use the bathroom more often!
My experiences while fasting
My first fast was a 16:8 windowed fast (16 hours fasting and 8 hours eating), in combination with a fairly strict Ketogenic diet. As it was my first time fasting, I did not know how long to intermittent fast for. In the end, I decided to try it for one month and see what the effects were on my body. I also had one cheat meal a week, but purposefully didn’t overindulge. I just enjoyed some sneaky carbohydrates such as a wrap or burger (no chips!).
It had great effects on my body while fasting, including increased mental clarity and weight loss. Although the first week was hard as my body adapted, I was feeling the benefits within a few days. Thankfully, I didn’t have any of the common issues such as irritability or get what is known as “keto flu”, although I did suffer from a feeling of fatigue for the first few days.
While I felt like I could keep going after the initial month, I was missing some of my favorite carbohydrate meals, and so I came off the diet and fast. Since then, I have been on and off with fasting, doing a month here or there to change things up. The only time I have suffered any negative effects has been when I wasn’t fasting.
I believe fasting can be used to assist an individual with a healthier lifestyle. In my opinion, on its own the effects are minimal. But when combined with regular exercise and a healthy diet, fasting can have amazing effects.
I think that while you may do a more difficult fasting type, such as the 20:4 windowed fast or a 5:2 fast, once you reach your goals it would be feasible to scale back your efforts. This may mean a more relaxed fast such as a 16:8 or perhaps including a cheat meal (or perhaps an extra one) into your diet.
What do others think?
From friends who have done fasting to individuals sharing their experiences online, there is a multitude of personal stories about fasting. I haven’t found anyone who has stated that they have had negative effects from fasting long term. I have found however that there is a large amount of praise for fasting and its benefits in both the long and short term.
If the lack of long term scientific evidence worries you, you could always do fasting for a short period of time, revert to a normal lifestyle, and later choose to try fasting again.