Benefits of coffee when fasting
Although fasting is an ancestral practice, the science is still fairly new. Research does not yet answer with certainty if coffee breaks a fast in every scenario, however there are many studies that prove the benefits of fasting in the presence of coffee and caffeine in general.
From these studies we can infer that coffee, for the most part, does not harm a fast, and in fact it may actually enhance certain beneficial processes. Understanding the role that coffee plays during a fast is best done by examining the different goals of fasting individually. For the purposes of simplicity, we’ll first discuss whether or not black coffee breaks a fast.
Fasting for Body Composition
One of the most common reasons fasting has become so popular is because of its ability to dramatically impact body composition and promote fat loss. Due to its ability to suppress hunger and increase fat oxidation, coffee actually assists in mobilising fatty acids and may enhance fat loss.
Coffee has also been shown to activate the Nrf2 pathway, which is a genetic pathway that turns on over 200 genes, many of which are related to detoxification and fat loss.
Verdict: Black coffee probably doesn’t break a fast, and likely enhances the benefits.
Fasting for Energy and Mental Clarity
The energy and mental clarity that comes from a ketotic state during fasting is only emphasised with coffee. It’s no surprise that caffeine provides the body with an energy boost, but studies show that it also provides a cognitive boost that includes improved alertness, attention, and concentration. Due to its impact on energy levels, it is worth noting that consuming coffee late in the day will likely have a negative impact on sleep quality. Considering that sleep quality is a strong predictor on energy and mental clarity the following day, as well as overall health, we suggest consuming your coffee within the first half of the day, so that you can reap all the benefits and still achieve deep, restorative sleep.
Verdict: Black coffee probably doesn’t break a fast, and likely enhances the benefits.
Fasting for Gut Health
Fasting can make your gut stronger by giving it a rest from digestion, boosting its resilience against stress, increasing levels of good bacteria, and killing off harmful microbes. It’s no surprise that what we eat also influences our microbiome, and the latest science suggests that coffee, tea, and even wine might actually have a beneficial effect on your microbiome. The consumption of coffee (even decaffeinated) has been linked to a reduction in leaky gut as well as a more diverse colony of bacteria in the digestive tract. Coffee is also rich in polyphenols, which are antioxidants that act as fuel for microbes. However, if you experience any adverse effects from drinking coffee on an empty stomach, such as heartburn or acid reflux, you may want to forego the coffee during your fast.
Verdict: Black coffee probably doesn’t break a fast, unless you experience gastrointestinal issues from drinking it on an empty stomach.
Fasting for Longevity and Cellular Health
The health benefits of coffee on long-term health are well studied and show promise for daily coffee consumers. However, is coffee safe to drink during a fast when your goal is autophagy? It seems as though the science, while lacking in definitive long-term studies on humans, may point to yes.
A recent 2014 study conducted on mice showed that the consumption of both caffeinated and decaffeinated coffee triggered autophagy in vivo. In other words, not only does coffee likely not break a fast when it comes to longevity, it may even enhance the anti-aging effects (probably due to the polyphenols in coffee, not the caffeine).
Verdict: Black coffee probably doesn’t break a fast, and likely enhances the benefits.
Fasting for Boosting the Immune System
Fasting itself is well-known to have potent beneficial effects on the immune system. But does coffee hinder these effects? Although caffeine is generally anti-inflammatory, its impact on the immune system can vary from person to person. The relationship between coffee and inflammation is not yet clear, but studies suggest two autoimmune disease risk genes (NAT2 and HLA) may be involved in determining if coffee is helpful or harmful when it comes to healing or aggravating autoimmunity. For this reason, people suffering from autoimmune disease are advised to initially remove coffee from their diet and then reintroduce it later on.
Verdict: It depends on your personal health history. If you know you experience negative effects from caffeine or coffee, or have an autoimmune disease, you might want to avoid coffee during a fast.
Bottom Line: For most intents and purposes, if you stick to black coffee, you will not break your fast.
When you start to add calories to your coffee in the form of MCT powder you will technically break the fast. However the benefits will be the consumption of good fats which will enhance further fat burning by the way of ketosis. It will also help you stave off hunger and even extend your fasting period.
Coffee with sugar will break a fast in any scenario, due to sugar’s tendency to spike blood glucose and kick the body out of a fat-burning state.