Does Coffee Break Your Intermittent Fast? | Dr. Michael Van - The Science Of Optimal Human Performance
Everyone who has followed me knows I am one of the biggest advocates of fasting there is. The amazing topic of fasting inspired me to write my first book on this for crying out loud! I incorporate several fasting routines in my life, from daily intermittent fasts to extended 24-48 hour fasts. One thing that really helps me get through the fasting period is coffee. Black, organic coffee. No calories, but a beverage I thoroughly enjoy.

We have brilliant doctors out there who study fasting and offer their unique perspectives. We have experts like Dr. Satchin Panda of the Salk Institute, who has studied time-restricted eating and circadian biology extensively, and believes that coffee or any beverage other than water alone technically breaks your fast. The reason being is because the caffeine needs to be metabolized and can potentially disrupt your biological circadian rhythms.

Caffeine is absorbed in the stomach and enters the blood stream. Once in the blood, it can then direct its effects on the brain, kidney, liver, and heart. Caffeine can affect your biological rhythms through multiple pathways, mostly due to the effects on adenosine receptors. Long story short, caffeine is very structurally similar to a neurotransmitter called adenosine. Adenosine binds to receptors in your brain to make you feel tired. When you consume caffeine, this can also bind to these same receptors, blocking adenosine from binding. We will discuss more on this topic later in another article.

With that said, it has been widely accepted that this beverage is perfectly ok to consume during a fasting period. Coffee, along with tea, has pretty much a staple for many people’s fasting regimens. I still believe it is, and I will tell you my reasoning, especially in how it relates to fasting.

  • 1. First of all, coffee seems to be able to increase your body’s ability to utilize fatty acids as fuel. This helps support the effects of fasting, especially in relation to increasing fat burning and the utilization of ketones.
  • 2. Coffee actually reduces the likelihood of type II diabetes by improving insulin sensitivity and your glucose tolerance, although studies on this have been mixed.
  • 3. Coffee increases cellular autophagy! Remember, autophagy is a cleaning out process of your body where it rids itself of cellular waste products. Kind of a detoxing mechanism the body goes through. Out with the old, in with the new type of thing.
  • 4. Finally, coffee actually increases something called AMP-K. This is an enzyme that promotes fat burning and increases exercise performance.

We see that drinking coffee actually enhances the effects of fasting in many ways. In a sense, it is a way to biohack your fast with all these similar and complimentary benefits. If coffee is consumed in the morning hour, which I recommend, then I think it will have a minimal effect on your biological clock. After all, we want to be awake in the morning. Since coffee has a half-life of 6 hours, we definitely want to be mindful of not consuming this later in the afternoon to prevent proper sleep and melatonin release.

We already know that coffee consumption results in the inhibition of several metabolic diseases as well as a large reduction in overall and cause-specific mortality! It actually makes you live longer! That alone is enough for me to consume coffee during my fasting period. Give it a try. Not everyone responds well to coffee, but I think if it works for you, then it should definitely not be discouraged.

References:

1. http://blog.mycircadianclock.org/caffeine/
2. http://stm.sciencemag.org/content/7/305/305ra146
3. https://www.ncbi.nlm.nih.gov/pubmed/21352949
4. https://www.ncbi.nlm.nih.gov/pubmed/24769862/
5. https://www.ncbi.nlm.nih.gov/pubmed/15010440?access_num=15010440&link_type=MED&dopt=Abstract
6. http://care.diabetesjournals.org/content/27/12/2990#ref-1
7. https://link.springer.com/article/10.1007%2Fs10068-010-0151-6
8. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4632959/