Tea 101
Fasting And Tea – Understanding The Science

Fasting And Tea – Understanding The Science

I personally stumbled upon the practice of fasting for health 3 years ago. I found it to be absolutely insane and against all that I have learned in my past, but decided to give it a try. Here I am 3 years later and an absolute advocate for fasting! It has become a daily practice for me and something I have found to personally work well in my life.

After going down this path of fasting I was worried I would have to sacrifice my love for tea, or only enjoy it at certain times. In this article, I am going to look at what is currently being explored in the field of fasting and tea and how these two can go hand-in-hand, as well as possibly counteract each other.

I am NOT a trained physician! What I will be sharing is primarily from personal experience and research papers from trusted physicians and doctors. This is meant to be a guide to help start the thought process for you and hopefully educate a bit.

Let’s dive into the relationship of fasting and tea!

What Exactly Is Fasting?

There are many definitions of fasting nowadays…that is because there are actually different types of fasting! The general definition of a fast is an abstinence from calories, or limiting of one’s calories, especially when voluntary and as a religious observance (1). While the religious observance is part of fasting, we will not be getting into the details of that due to the fact that it varies from religion to religion and holds different definitions.

The multitude of definitions I am referencing comes primarily from the duration of the fast. These are a few of the major types of fasting practiced:


  • Prolonged Fasting: This style is a type of fast where people voluntarily go for over 24 hours without calories.
  • Intermittent Fasting: This style is an overview for a bunch of subcategories below. It focuses on the idea of eating for a designated time and then fasting for a designated time. Below I will describe the types of intermittent fasting!
    • 16/8: You fast 16 hours and eat within an 8-hour window. The hours can be changed to 14/10 or 18/6, but generally 16/8 is followed.
    • 5/2: You eat a calorie restricted diet 2 days of the week and eat normally the other 5. Calorie restricted diet here refers to 500 or fewer for women and 600 calories or fewer for men.
    • Eat-Stop-Eat: Similar to 5/2, except you fast completely from calories on your two days and eat normally the other 5.
    • Alternate Day: Every other day you fast or eat a calorie restricted diet and then eat normally the next day.
    • Warrior Diet: You only eat one large meal throughout the day. No snacking or any other calorie intake other than that one large meal.

How Does Fasting Work?


There are multiple types of fasting as described above, so how do they work in the body? It is not a simple answer unfortunately. There are many variables that need to be considered in order for this to be answered. One of the biggest being difference between men and women’s biology. I will try to generalize most of how fasting works in the body, but know that it is different for everyone!

When you body begins to go into a fasted state, chemistries change and new pathways/mechanisms begin to work. In a fasting state, your body’s blood glucose levels begin to drop. This leads to a decrease in insulin production. Insulin is a hormone response when you intake calories that causes your liver, muscles and fat cells to store glucose. When fasting and this insulin drops, your body looks elsewhere for energy. Initially this is the carbohydrates you have most recently eaten, but once those are all used up (~12-14 hours) the body starts burning stored fat.

It is important to note that in order to reach this state of burning fat you need to deplete your stored glycogen. This is why you cannot eat or drink any calories. This is why most of the fasting techniques require at a minimum 14 hours. The state you get into when you begin to burn fat is known as ketosis. This is because when your body burns fat instead of carbohydrates as energy it forms ketones.

Autophagy Process!

Another mechanism that I want to touch on is autophagy. Autophagy is the bodies self-cleansing process. What does this mean? When your body is depleted of food, the cells scavenge around for other energy sources. At a certain point, the healthy and strong cells of the body begin to consume the weak, broken or dying cells for energy! This is good because it allows us to get rid of potentially dangerous cells that if accumulated could cause cancers, inflammation and other diseases!

Now that we have touched on what fasting is, what it does and how it works, lets talk about how tea affects it!

How Does Tea Affect Fasting?

To the true fasting purists, anything but water breaks a fast. So they would say tea cannot be taken in during a fast.

Tea, without sweetener, is a calorie free beverage. So is it as simple as that to say that tea has no effect on your fast? Unfortunately, it is not that simple.

Tea contains many chemical compounds. Those include, polyphenols, caffeine, minerals, vitamins, amino acids & trace amounts of carbohydrates. While these levels of carbs, vitamins, and amino acids are not enough to effect your macronutrient levels (fat, carb and protein levels in grams), molecularly they may have an affect.

One of the compounds that is under question especially is caffeine. Caffeine is known to reset the internal clock in our body, but what is not fully understood is how it affects our circadian rhythm and metabolism. While there is actually a little evidence that shows the caffeine may have a positive effect on your fast, by boosting autophagy and other beneficial mechanisms, many circadian rhythm specialists state otherwise.

One doctor that has dedicated much time and research to this field is Dr. Satchin Panda. Him and Dr. Rhonda Patrick share a fascinating conversation about this topic. Check it out here or click the image below!

Tea has been shown to help with hunger pangs and keep people’s energy up during prolonged fasts. Tea can give you a much-needed break from water when taking time away from calories.

Is Fasting Right For Me?

I personally have tried all the above fasting techniques. They all have similar, but different results for me. I now have found a nice balance of a mixture of them that works well and is not super strict. Ultimately, you have to find what works well for you!

I drink tea while I fast. I find it gives me a greater appreciation for the tea as well as allows me to feel the effects of both the tea and fasting.

Ultimately, it is up to you to decide if fasting is right for you. Do your own research! Find trusted sources with dedicated research to this topic! Talk to a physician about this! Be your best advocate.

Hopefully this opened your mind to fasting and tea. If you are interested in this, you may be asking well wait…are there certain teas that are better than others? Well, we will be having another post out soon that will go into specifics about each tea, what are the best or worst, why and more! Be on the look out for that!

Let us know in the comments if you have anymore questions about fasting and tea. Share with a friend too!


1. https://www.dictionary.com/browse/fasting

2. https://wexnermedical.osu.edu/blog/does-intermittent-fasting-work#:~:text=In a fasting state, blood,and begins burning stored fat.

3. https://pubmed.ncbi.nlm.nih.gov/15640462/

4. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC329619/

5. https://pubmed.ncbi.nlm.nih.gov/12107252/

6. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3946160/

7. https://pubmed.ncbi.nlm.nih.gov/21410865/

8. https://medium.com/@drjasonfung/green-tea-helps-fasting-1f9aded8fa35

9. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6412948/

10. https://www.foundmyfitness.com/episodes/does-drinking-coffee-break-your-fast

6 thoughts on “Fasting And Tea – Understanding The Science

    • Author gravatar

      Thank you so much for this excellent post! I periodically fast for religious reasons (I am a devout Christian), but I also sometimes fast to clear all of the junk out of my system (I’ll be the first to admit that I don’t have the greatest eating habits in the world. Haha). i too love tea, but I never thought about the connection between tea and fasting until now (I don’t usually drink tea during my fasts). As you have mentioned, unsweetened tea doesn’t contain any calories, and as such, I could drink it without breaking my fast. I’ve just restocked my tea, and I will definitely start incorporating it into my fasts (I plan on doing the next one in a couple of weeks)! Great read! God bless you!

      • Author gravatar

        C.N. thank you for the insight! I agree, there are so many awesome reasons to fast. Let us know how your fasts are when you incorporate tea! If you want recommendations on what tea to use for your fast, check out the post on “Tea For Fasting”!

    • Author gravatar

      Fasting and tea is a very interesting article with new information I was not aware of, I never knew fasting was technically for 24 hours. This is a good website to learn about tea, and I am a regular tea drinker so I will be a regular reader from now on


    • Author gravatar


      Thanks for putting together this great article.

      I’m a fan of intermittent fasting, and longer fasts every few months which I do to trigger autophagy.

      I’ve always used coffee to help me through a fast, and the video you linked to was very informative for me.

      I’m going to try tea instead of coffee next time, as the caffeine content is slighty lower. As you point out yourself, there is no clear science as to whether or not caffeine can interfer with autophagy.

      Thanks again!

    • Author gravatar

      This is an excellent post and the topic is closer to my heart both for health and religious reasons. Like you said in this article as well, I have done various types of fasts including 24+ fast over a period of time according to my religion. I’ve also done a 16/8, 12/12/, 14/10 18/6 etc and you are right they all bring tremendous benefits to your physical, mental and spiritual health. I highly recommend it to anyone who haven’t got any underlying health issues, will greatly benefit from it.
      I personally don’t drink anything during the intermittent fasting as I feel I benefit greatly without any drink. My energy and mental clarity level goes really high. Plus when I drink water/tea I get more hungry. I’ve also done a post on my website on this topic. Please check it out if you can.

      Thank you for this great information

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