6 Benefits Of Caffeine While Fasting

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Caffeine While Fasting

Taking caffeine while fasting may not seem like an ideal drink if you’re only just starting with the diet. For caffeine lovers, however, you will be delighted to know it’s still on the menu during your fast.

Aside from water, drinking coffee is allowed, provided you take it with no additives. While some may argue it isn’t genuinely fasting, consuming caffeine during your fasting window has beneficial impacts.

Let’s dive deeper into how caffeine can benefit you.

Why Do People Fast?

Intermittent fasting (IF) has become popular as a fitness trend, but it originally started as a religious practice. It is a way for believers to strengthen their connection in both the body and the soul. Today, people fast for health reasons or implement it as their way of life.

With intermittent fasting, you only eat during a specific time. Fasting for a certain number of hours each day or eating just one meal a couple of days a week can help you lose weight, which is its main selling point. Intermittent fasting prolongs the period when your body has burned through the calories consumed during your last meal and begins burning fat.

Depending on your goal, fasting can be done in different ways and at different times—another of its many advantages.

Intermittent Fasting And Caffeine

When starting intermittent fasting, you will have to consider how you can go without food for several hours. This is when liquids play a support role during your fasting period, specifically with caffeine.

The rule is that you only drink very low or no-calorie beverages during your fast. Coffee and even tea just so happen to fit right into that rule. When done right, you will be able to prolong your fasting hours when you drink coffee or tea.

Why Can You Drink Caffeine While Fasting?

The reason why you can drink moderate amounts of caffeine, especially coffee, during fasting periods is that it contains very few calories and is unlikely to break your fast.

Drinking coffee while fasting falls on the modified version of intermittent fasting. For strict intermittent fasting, however, you should avoid any drinks containing calories and stick to consuming water.

Benefits Of Fasting And Caffeine

While intermittent fasting can promote weight loss, these are the health benefits you can gain from it:

1. Reduced Inflammation – studies have shown that intermittent fasting and coffee consumption may reduce inflammation markers. When used together, the effects of caffeine and fasting may compound for increased anti-inflammatory activity1,2.

2. Better Brain Health – both drinking coffee and intermittent fasting have demonstrated promise in slowing mental decline and protecting against diseases such as Alzheimer’s and Parkinson’s3

3. Increased Autophagy – autophagy is the process by which your body breaks down old or damaged cells and regenerates new ones in their place. This allows your body to repair and heal on a cellular level, decrease inflammation, and more.Fasting is linked to higher levels of autophagy, as is with coffee which also boosts autophagy. Together, they may help the body fight aging, disease, and inflammation at greater rates4,5.

4. Improved Insulin Sensitivity – both fasting and caffeine may help manage insulin resistance, lower insulin levels, and reduce the risk of type 2 diabetes6. For this benefit, you’ll want to opt for a light roasted coffee, which more effectively manages blood glucose.

5. Boosted Metabolism – fasting and caffeine have been shown to increase your body’s metabolic rate, speeding up weight loss and promoting fat burn7,8.

6. Lessens Hunger – if you’re worried about hunger pangs during IF, a coffee intake may reduce the sensation of hunger. Many people say that caffeine, and warm beverages, help them to feel full. 

Types Of Coffee

The most recommended coffee for fasting sessions is black coffee since it contains no calories. An added benefit to it is that it can provide over 50% of your body’s energy for normal body functioning.

Other types of coffee, such as bulletproof coffee, can be consumed while fasting but in moderation. A typical bulletproof coffee has an average of 320 calories per cup, which doesn’t follow the strict intermittent fasting rule.

To have the full advantages of fasting, you may want to stick to black coffee consumption instead.

How Much Coffee Can You Drink While Intermittent Fasting?

You can drink black coffee up to 1–2 cups of coffee during your fast. The average nutrients in it may not be enough to initiate a significant metabolic change that would break your fast.

In general, drinking coffee moderately won’t significantly disrupt intermittent fasting. You just need to be sure that you’re only drinking black coffee and without any added ingredients in it.

What Can You Mix It With?

If drinking black coffee might not be that appealing to you, you can opt to add minimal amounts of these:

  • Nutmeg
  • Cocoa
  • Cinnamon
  • Almond Milk
  • Himalayan Sea Salt

What Should You Avoid?

While caffeine is permitted during intermittent fasting, it should be restricted to small amounts. At the same time, even though drinking black coffee is fine, adding the ingredients below can impact your metabolism and blood sugar, causing you to break your fast.

  • Milk
  • Cream
  • Plant-based Milk
  • Sugar
  • Creamers


It’s important to state that there is always a risk with how much caffeine you consume. When starting intermittent fasting, you should limit your coffee intake and see how your body may react to caffeine.

Since you are drinking coffee on an empty stomach, you may experience some discomfort. Some of these may be:


Caffeine can loosen your lower esophageal sphincter muscle, which is the valve between the esophagus and stomach9. This could cause acidic stomach contents to enter the esophagus, resulting in uncomfortable GERD symptoms, which refer to Gastroesophageal Reflux Disease.

Anxiety or Panic Attacks

If you face frequent bouts of anxiety and panic attacks, it’s better to skip coffee during intermittent fasting.

Bad Heart Health

If you have a pre-existing heart condition, avoid coffee. You should stay clear from this beverage during fasting if you suffer from high blood pressure or heart rate. 

Hormonal Imbalance

Excessive caffeine influences estrogen levels by distorting estrogen to progesterone ratio or creating an imbalance in estrogen metabolites. 


Coffee impacts the absorption of levothyroxine (used in thyroid meds). Coffee also contributes to estrogen dominance,  inhibiting T4 to T3 conversion.

Irritable Bowel Syndrome with Diarrhea (IBS-D)

Coffee stimulates the release of gastrin, the main gastric hormone. This speeds up intestinal transit time. Coffee can also stimulate the release of bile (which is why some people run to the bathroom soon after drinking coffee) and digestive enzymes.

What Else Can You Drink During Fasting?

Hydration is key to a successful fast. Some other liquids that can boost the beneficial effects of fasting and won’t break a fast are:


Intermittent fasting can be done easily and made bearable if you consume liquids during your fast. Drinks such as black coffee can be enjoyed while fasting just as long as they are consumed in minimal amounts.

The benefits of intermittent fasting can also be enhanced by coffee which includes reduced inflammation and insulin sensitivity.

As with any significant dietary or lifestyle change, discuss fasting and coffee consumption with your doctor before starting any fasting plan.


1 Paiva C, Beserra B, Reis C, Dorea JG, Da Costa T, Amato AA. Consumption of coffee or caffeine and serum concentration of inflammatory markers: A systematic review. Crit Rev Food Sci Nutr. 2019;59(4):652-663. doi: 10.1080/10408398.2017.1386159. Epub 2017 Nov 3. PMID: 28967799.

2 Mattson MP, Longo VD, Harvie M. Impact of intermittent fasting on health and disease processes. Ageing Res Rev. 2017 Oct;39:46-58. doi: 10.1016/j.arr.2016.10.005. Epub 2016 Oct 31. PMID: 27810402; PMCID: PMC5411330.

3 Nehlig A. Effects of coffee/caffeine on brain health and disease: What should I tell my patients? Pract Neurol. 2016 Apr;16(2):89-95. doi: 10.1136/practneurol-2015-001162. Epub 2015 Dec 16. PMID: 26677204.

4 Anton SD, Moehl K, Donahoo WT, Marosi K, Lee SA, Mainous AG 3rd, Leeuwenburgh C, Mattson MP. Flipping the Metabolic Switch: Understanding and Applying the Health Benefits of Fasting. Obesity (Silver Spring). 2018 Feb;26(2):254-268. doi: 10.1002/oby.22065. Epub 2017 Oct 31. PMID: 29086496; PMCID: PMC5783752.

5 Federico Pietrocola, Shoaib Ahmad Malik, Guillermo Mariño, Erika Vacchelli, Laura Senovilla, kariman chaba, Mireia Niso-Santano, Maria Chiara Maiuri, Frank Madeo & Guido Kroemer (2014) Coffee induces autophagy in vivo, Cell Cycle, 13:12, 1987-1994, DOI: 10.4161/cc.28929

6 Ding M, Bhupathiraju SN, Chen M, van Dam RM, Hu FB. Caffeinated and decaffeinated coffee consumption and risk of type 2 diabetes: a systematic review and a dose-response meta-analysis. Diabetes Care. 2014 Feb;37(2):569-86. doi: 10.2337/dc13-1203. PMID: 24459154; PMCID: PMC3898757.

7 Teruya T, Chaleckis R, Takada J, Yanagida M, Kondoh H. Diverse metabolic reactions activated during 58-hr fasting are revealed by non-targeted metabolomic analysis of human blood. Sci Rep. 2019 Jan 29;9(1):854. doi: 10.1038/s41598-018-36674-9. PMID: 30696848; PMCID: PMC6351603.

8 Bakuradze T, Boehm N, Janzowski C, Lang R, Hofmann T, Stockis JP, Albert FW, Stiebitz H, Bytof G, Lantz I, Baum M, Eisenbrand G. Antioxidant-rich coffee reduces DNA damage, elevates glutathione status and contributes to weight control: results from an intervention study. Mol Nutr Food Res. 2011 May;55(5):793-7. doi: 10.1002/mnfr.201100093. Epub 2011 Apr 4. PMID: 21462335.

9 Lohsiriwat S, Puengna N, Leelakusolvong S. Effect of caffeine on lower esophageal sphincter pressure in Thai healthy volunteers. Dis Esophagus. 2006;19(3):183-8. doi: 10.1111/j.1442-


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