Fasting Part 2 (Doing it Right and What Not to Do)
One nice thing about fasting is it’s hard to do incorrectly.
Not impossible, mind you, but pretty darn hard.
On its face fasting is simply restricting how much you eat for a set period. This is an easy concept to execute, but may be hard mentally.
Now, the inclusion of time-restricted eating protocols like intermittent fasting has made fasting a little bit more complicated, but it’s not rocket science.
As I mentioned in my previous article, fasting is a fairly safe endeavor, and the risks are quite low for an individual.
And while safe, it’s incredibly beneficial.
But still, even though fasting is inherently simple, some guidance can be applied to fasting.
Like, how long should you fast? And, how frequently? How much is too much? And so on and so forth.
Allow me to cover this in detail and tell you what I think is the best method to start fasting.
Hot to Fast Well for Maximum Benefit (and Safety)
One of the things about fasting that’s so beneficial is how your body essentially eats itself for a time and disposes of unneeded and unbeneficial cellular tissue.
This is referred to as autophagy and I’ve written about it before.
Fasting for 24-36 hours is enough to induce full-blown autophagy which is one of the best things fasting can produce from a health standpoint.
But a 24-36 hour fast is pretty ambitious for most, so let’s just break down what kind of fasting is available to you and how to approach it.
1 - Intermittent fasting/time-restricted feeding—Meals are consumed within a limited number of hours (such as 6-8 hours) each day, with nothing consumed during the other hours. This is also known as intermittent fasting.
2 - Alternate-day fasting: Eating is unrestricted every other day, and no or minimal calories can be consumed on the days in between.
3 - 5:2 eating pattern: Eating is unrestricted for 5 straight days each week, followed by 2 days of restricted caloric intake.
4 - Periodic fasting: Caloric intake is restricted for multiple consecutive days, such as 5 days in a row once a month, and unrestricted on all other days.
These are the most common forms of fasting.
As you can see in these profiles of eating, many times fasting is happening regularly. Every other day in some cases, or every 5 days in others.
What does this say about “how much is too much?”
It’s a good question.
I believe that if a person doesn’t have an eating disorder, or is not predisposed to an eating disorder, doing it as often as every other day is not a bad thing.
Of course, those with an eating disorder could encounter issues with fasting as they restrict eating enough that it causes harm to their body.
One way to ensure you’re not playing footsie with an eating disorder is by fasting and watching your BMI and other vitals (like resting heart rate and HRV). If you’re within the healthy range for your BMI and heart rate, then fasting is likely not detrimental to your health.
Again, the frequency with which you fast is only going to be harmful if you begin to consume fewer and fewer calories and nutrients to the point where your nutrient intake and body weight fall outside of the healthy ranges.
This is why the metabolic flexibility provided by these kinds of fasts can accommodate for periods of total food restriction - provided you’re getting enough nutrients and calories during your feeding periods.
I think if you’re new to fasting then intermittent fasting is the way to go. It’s easy to understand and it doesn’t require an incredible amount of mental fortitude and discipline to accomplish.
Once you gain the hang of that approach it won’t be hard to level up to the other, more “extreme” fasting methods.
Now that you have a good summary of how to do it (and how often), let’s get into how to carry on during a fast and how to end a fast.
How to Fast and Break a Fast Correctly
One of the questions people often ask when fasting is “Can I have anything besides water during a fast.”
The answer is both yes and no.
The jury is still out on whether or not adding in additional calories (like those from coffee) interrupts getting into an autophagic state. And by that I mean there haven’t been exhaustive studies done on ultra-low caloric intake and what it does to the fasted body.
So, if you want to be extra sure nothing happens, refrain from consuming anything other than water (enhanced only with electrolytes).
Now, there is an argument that if you’re doing intermittent fasting, or other kinds of time-restricted eating you can have a few calories (less than 10 in a day) and still get the benefits of improved insulin sensitivity and BDNF increases.
Again, the benefits of fasting are varied and vary by the goal.
The other question comes around breaking a fast.
In most of the fasts mentioned above breaking a fast of 16-48 hours can be done without much thought. Though, you should eat something high in fat and protein because your digestive system won’t be extremely upset by those kinds of nutrients.
A longer fast (say over 3 days) should be broken with a light meal consisting mostly of fat and protein, but it really should be small. You won’t harm yourself if you eat a large meal, but your gut may not react favorably and you might find yourself ducking into the bathroom more often than normal.
This is about it, although I’m sure you may still have questions. The best individual advice on this will come from your healthcare provider.