The world is full of pathogens that can harm our bodies
– like the now infamous COVID-19 from the Novel Coronavirus.

The good news is that our bodies generally do a good job fighting them off…
…but sometimes we want to do more to protect ourselves…
…so your question may be:

How do you boost your immunity – with fasting and ketosis?

You know there are many health benefits associated with fasting and ketosis, things like:

[+] Burn fat
[+] Spare muscle
[+] Detox
[+] Recover faster from workouts and injuries
[+] Healthier skin, joints and bones
[+] Reduce risk for Cancer, Diabetes, Heart Disease, Alzheimer’s, Parkinson’s and Stroke
[+] Clean up the gut
[+] More time
[+] More focus
[+] Improve mood
[+] Save money

These are great but, because of the novel Coronavirus and COVID-19, I’ve been asking:

Does fasting help fight off viral infections?

I initially thought that ketosis (from fasting, eg) was better for fighting off bacterial infections and that eating food (specifically carbs) would help fight a viral infection. I think the saying goes something like this:

Starve a cold. Feed the flu.

However, in my research I found (as usual!) that it’s not quite so simple…

The challenge with research these days is that it’s too easy to find studies that support just about any hypothesis.

Fasting is simple in practice but complex in its effects.

To answer whether or not fasting helps fight infections (and specifically viral infections coming from Coronavirus), it helps to understand what’s going on when you fast.

Two of the main actions taking place in your body are:

[1] Ketosis
[2] Autophagy

Thus we can start by first looking at research around ketosis and infections. If you’re a fan of keto your bias may lead you to the following conclusion:

Keto kills viral infections.

As I mentioned earlier, you can search and find studies and evidence to support just about any hypothesis.

So, yes, if you like, I can share the 1 study (and there are likely more!) I found showing that keto helps fight viral infections.

Mice fed a ketogenic diet were better able to combat the flu virus than mice fed food high in carbohydrates, according to a new Yale University study.
Ref: https://www.sciencedaily.com/releases/2019/11/191115190327.htm

Keto lowers inflammation.

I think this is an important point in light of COVID-19 because what seems to be the lethal problem is the body’s exaggerated immune response. This means that you have too much inflammation.

It would then seem to make sense to do what you can to lower inflammation. Ketosis undoubtedly lowers inflammation. 

However, I’m not aware of any studies looking at what happens with COVID-19 while in ketosis – or if it’s even possible to be in ketosis during the exaggerated inflammatory response.

Virus depends on sugar.

My research suggests that viruses need glucose to infect their hosts.
Ref: https://www.ncbi.nlm.nih.gov/pubmed/31732517

We know that fasting and ketosis lower glucose in the body significantly.

Therefore, we can hypothesize that ketosis greatly reduces the risk of viral infections.

How is keto bad for viral infections?

Good question. I’ve been searching for the answer… and I can’t find it. There are articles claiming that there’s no “proof” that keto prevents or fights COVID-19.

However, these articles I’ve seen point to no convincing evidence to back up their statements.

In fact, after doing my own research, I’m now convinced that fasting and ketosis can actually both help prevent infection from the novel coronavirus AND fight the virus. Not what I expected! 

What about autophagy to boost your immunity?

Wait a sec, what is autophagy?

This is what happens after fasting or restricting protein consumption for an extended period of time (hitting “peak autophagy” after about 2 days).

In simple terms, autophagy is your body’s way of “taking out the trash” by cleaning up dead and dying cells, along with viruses, bacteria and fungi.

When you’re eating, your body is more anabolic, meaning that it’s growing – and it has little time to clean up dead and dying cells.

When you fast, your body has time to do its thing and clean itself up. So, yes, autophagy seems to be good for boosting your immune system.

What about autophagy for the novel Coronavirus and COVID-19?

Yes, it seems there’s evidence that autophagy helps to fight the MERS coronavirus. 

A recent study revealed a disruption to the cellular recycling process in cells infected with the virus. This result clearly indicated that the MERS pathogen benefits from an attenuation of the cellular recycling process.
Ref: https://www.drugtargetreview.com/news/55567/autophagy-the-key-to-effective-mers-coronavirus-treatment/

This sounds like great news for people ramping up autophagy via fasting. However, the same study also explains that Coronavirus actively inhibits autophagy. Thus it’s still a guess as to how effective fasting might be – if it all.

For general immunity, fasting for autophagy seems like it can be a great benefit; however, for viral infections, its effect remains mostly uncertain.

Conclusion: Find the “right” amount of fasting.

In general I think most people eat far too much and too often than their bodies require leading to lower immunity and chronic disease.

For many people, fasting is scary…but it shouldn’t be. After all, most of us are already fasting while we sleep at night. Simply extending that fasting period can have major beneficial effects on your body and your health.

What’s the right amount of fasting for you?

Leave a Reply

Your email address will not be published.


{"email":"Email address invalid","url":"Website address invalid","required":"Required field missing"}

About the Author Jason Ryer


Jason Ryer is a Certified Breath Coach, Cold Therapy Guide, and former tech entrepreneur who combines ancient wisdom with modern science to help others optimize their wellbeing. After working as a software engineer at IBM and serving in the Peace Corps in Bolivia, Jason discovered the transformative power of breathwork and cold therapy. A certified Bulletproof Coach and trained by Wim Hof, he has guided over 1,000 people through breathwork and ice bath experiences. Now based in Thailand, Jason leads the Zen Strength movement, helping individuals reconnect with their natural resilience through breathwork, cold exposure, and mindset training. His journey from tech innovator to wellness guide reflects his mission of reuniting people with nature and optimal health.

Get my latest biohacks, health and wellness updates.

I'll share my updates, along with my latest biohacking secrets - to help you achieve weight loss and beyond: Burn Fat, Build Strength, Increase Immunity, Detox, and Boost Energy!