Intermittent Fasting 101: Can You Drink Coffee During the Fast?

Intermittent Fasting 101: Can You Drink Coffee During the Fast?

What is Intermittent Fasting?

Intermittent fasting (IF) is an eating habit characterized by frequent, brief fasts. Rather than restricting what you eat, intermittent fasting limits when you eat by incorporating lengthy periods of fasting into your routine. 

There are several forms of intermittent fasting plans, but they all rely on selecting regular periods for eating and fasting. The 16:8 technique is the most popular, in which you skip breakfast and limit your daily eating window to 8 hours, followed by a 16-hour fast. 

Most people who use this strategy fast for 16 hours per day and consume all of their calories during the remaining 8 hours. Other prominent intermittent fasting methods include alternate day fasting, the 5:2 diet, and eating within a 6- to 8-hour window each day.

The key claimed benefits of intermittent fasting include fat reduction, improved metabolic health, greater lifespan, and improved cognitive function. Intermittent fasting, according to proponents, causes a calorie deficit without the need to intentionally control calories, making weight loss more manageable. It may also improve hormone function, reduce inflammation, and boost biomarkers associated with health and lifespan. 

More study is needed, but preliminary findings indicate that intermittent fasting may be an effective and long-term dietary strategy for weight reduction and metabolic health improvement for some people.

Different Types of Intermittent Fasting

Intermittent Fasting 101: Can You Drink Coffee During the Fast?

Intermittent fasting is a common diet technique, and there are various distinct methods:

16:8 method: This entails fasting for 16 hours each day and limiting feeding time to eight hours. For example, skip breakfast and just eat from 12 to 8 p.m.

5:2 diet: This strategy entails eating regularly five days a week while limiting calories to 500-600 on two of them.

Alternate day fasting: Fast every other day. On fast days, some people ingest between 0 and 500 calories.

The Warrior Diet: Fast during the day and eat a large meal at night. A typical fast lasts 20 hours, with a 4-hour meal window.

Eat-Stop-Eat: Follow a 24-hour fast 1-2 times a week while eating normally on the other days.

OMAD: Eat only one meal each day, resulting in a daily 23-hour fast. 

There are no clear guidelines for intermittent fasting. Many people tailor their techniques to their specific lifestyles and tastes. However, all varieties need reduced meals and calorie intake for specific periods.

Does Drinking Coffee Break Your Fast?

Understanding whether coffee interferes with the fasting state requires understanding what “breaking a fast” entails. The basic purpose of fasting is to redirect the body’s energy source from glucose (obtained from eating) to stored fat. 

This shift has several metabolic advantages, including higher insulin sensitivity and fat burning.

Consuming calories is often seen as breaking a fast. Plain black coffee, on the other hand, has little calories (2-5 per cup), which are inadequate to break the fast. Black coffee does not greatly affect insulin levels or fat oxidation, therefore it does not technically break a fast.

However, adding sugar, milk, or cream to coffee adds calories and may cause an insulin response, thus “breaking” the fast by altering the body’s metabolic state. As a result, how you enjoy your coffee has a significant influence on your ability to fast.

Can You Drink Coffee During Intermittent Fasting?

Yes, you can drink coffee while intermittent fasting, with certain limitations. Black coffee is widely accepted among the fasting community due to its low-calorie content, which is unlikely to seriously disturb the fasting process. 

In fact, coffee can be good since it increases alertness and may improve the fasting experience by decreasing hunger.

Benefits of Coffee While Fasting

  • Caffeine suppresses appetite, making it simpler to stick to the fasting window.
  • Caffeine improves the metabolic rate, which might help you burn more calories during the day.
  • The combination of coffee and fasting can boost lipolysis, the process by which the body burns down fat.
  • Coffee includes a high concentration of antioxidants as well as vitamins and minerals such as magnesium, potassium, and vitamin B.

Tips for Drinking Coffee While Fasting

  • Drink your coffee black. Adding cream, milk, or sugar to your coffee breaks your fast. Stick with black coffee, espresso, or Americanos.
  • Limit your coffee intake. While a cup or two of black coffee is unlikely to interfere with your fast, drinking coffee all morning may undermine its advantages due to acidic effects on the gut. Consume coffee in moderation.
  • Don’t consume coffee too late in your fast. Caffeine in coffee may make it difficult to fall asleep if drunk late in your meal window. Drink coffee early in the day.
  • Select high-quality coffee. Choose fresh beans and boil your coffee thoroughly. Poor-quality coffee is more likely to cause digestive problems and pain. 
  • Stay hydrated. To keep hydrated during your fast, drink plenty of water along with your coffee.
  • Pay attention to your physical sensations. Pay attention to how you feel after consuming coffee while fasting. If you suffer from headaches, anxiety, sleeplessness, digestive difficulties, or other disorders, try lowering or eliminating your coffee intake during fasting times.

Potential Side Effects of Coffee and Fasting

Drinking coffee while fasting has several possible drawbacks to be aware of.


Coffee contains caffeine, a stimulant that can make it difficult to fall or stay asleep. This is especially true if you drink coffee late in the day. Intermittent fasting can already disrupt sleep, so adding coffee can compound the problem.

Anxiety or jitters

Caffeine’s effects vary from person to person. Large doses of coffee may produce anxiety, jitteriness, fast pulse, and other unpleasant symptoms. This can be disruptive during a fast.

Heartburn or acid reflux

Coffee’s acidic nature can irritate the digestive tract, particularly when eaten on an empty stomach. Those who suffer from heartburn or reflux may wish to minimize their coffee intake during the fasting window.


Heavy coffee consumers who skip their normal cups during a fast may have withdrawal headaches. Caffeine withdrawal can occur when coffee consumption is abruptly reduced.

Hunger pangs

For some people, coffee may increase rather than decrease hunger. Coffee releases gastric acids, which can induce stomach rumbling. Hunger sensations may continue despite fasting.

Blood sugar spikes

Caffeine in coffee can induce blood sugar fluctuations, particularly when no other nutrients or meals are ingested. This may result in cravings, irritation, and decreased energy. Those with blood sugar management concerns should limit their coffee intake while fasting.

The trick is to be conscious of your unique tolerance and sensitivity. Not everyone will experience these possible drawbacks of coffee while intermittent fasting.

Other Alternative Drinks While Fasting

Intermittent Fasting 101: Can You Drink Coffee During the Fast?

When intermittent fasting, you should avoid calorie-containing beverages, artificial sweeteners, and those that may cause an insulin surge. Aside from ordinary coffee or tea, there are various beverage alternatives to consider:


Staying hydrated is essential. Plain water is always a safe bet during fasting periods. You may have it cold, heated, simple, or flavored with lemon, lime, cucumber, or mint. Getting adequate water reduces hunger.

Unsweetened Tea

Both black and herbal teas are suitable options for fasting. Green tea contains antioxidants, whilst mint and ginger tea improve digestion. Avoid sweetened teas, although you can add lemon, lime, or a splash of milk.

Sparkling Water

For some bubbles, try mineral or sparkling water. Choose unflavored or fruit-flavored types over ones with artificial sweeteners. Read the labels to see how much sodium is added.

Apple Cider Vinegar Drinks

Some individuals prefer diluting apple cider vinegar in water for a tart, appetite-reducing drink when fasting. Make sure you use organic, unfiltered ACV. Start with 1 tablespoon in a glass of water and adjust the flavor as required.

Bone Broth

Drinking bone broth is a great method to gain protein, electrolytes, and minerals when fasting. Choose handmade or organic, low-sodium options. Bone broth may help to reduce hunger.

Vegetable Juice

Fresh vegetable juices without fruits or sweets are excellent fasting drinks. Juice celery, spinach, kale, cucumber, fennel, or greens for essential nutrients and enjoyment. Be careful with beet or carrot juice because it contains more sugar.


Drinking coffee, particularly black coffee, can help with intermittent fasting objectives without breaking the fast. Not only does it improve alertness and maybe accelerate the body’s shift into a fat-burning state, but it also makes fasting more pleasurable for coffee drinkers. 

Nonetheless, it is essential to be aware of individual sensitivities to coffee and to eat it in moderation, ensuring that added components do not accidentally break the fast.

If you enjoyed this article, you may also want to read this article Can Your Favorite Coffee Guard Against Liver Issues?

*This information is not intended to serve as a substitute for professional medical or dietary advice tailored to individual needs.

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Dr. Kimberly Langdon

Kimberly Langdon

Dr. Kimberly Langdon has been an MD for 31 years, board-certified obstetrician/gynecologist with 19-years of clinical experience. She graduated from The Ohio State University College of Medicine, earning Honors in many rotations. She then completed her OB/GYN residency program at The Ohio State University Medical Center, earning first-place accolades for her Senior Research Project and Score of 98th percentile on a National Proficiency Test.

During her clinical career, she delivered over 2000 babies and specialized in minimally invasive procedures, menopause, endometriosis, menstrual disorders, and polycystic ovarian syndrome. After retiring from clinical practice, she founded a medical device company to commercialize her two patented and four patent-pending medical devices for both life-threatening and non-life-threatening infections.

Kimberly Langdon M.D.

Founder and Chief Scientific Officer, Coologics, 2010-present
The Ohio State University College of Medicine, Doctor of Medicine 1987-1991
The Ohio State University Hospital Department of Obstetrics and Gynecology Residency Program 1991-1995
Private practice 1995-2010

Po-Chang Hsu

Po-Chang Hsu

Po-Chang Hsu, M.D., received his medical doctorate from Tufts University School of Medicine in Boston. During his medical school training, Dr. Hsu worked with various patients, including adult and pediatric patients with acute and chronic conditions. Dr. Hsu’s interests include neurology, psychiatry, pediatrics, and sleep medicine.

Before medical school, Dr. Hsu finished a master’s degree at Harvard University and wrote a thesis on neuroimaging in schizophrenia patients at Brigham and Women’s Hospital, a Harvard Medical School-affiliated hospital. Dr. Hsu was also a part of the 2008 NASA Phoenix Lander Mission team, which sent a robotic spacecraft to the North polar region of Mars. Dr. Hsu also had research experience on neuroimaging in neonates at Boston Children’s Hospital, another Harvard Medical School-affiliated Hospital.

Since graduating from medical school, Dr. Hsu has worked as a full-time medical writer and consultant. In addition, he has experience writing and ghostwriting books and articles for physicians and health technology start-up companies. Dr. Hsu believes good communication between healthcare providers and patients creates the best results.


-Peer Reviewed Journal Article:
Kounaves, S.P., Hecht, M.H., West, S.J., Morookian, J.-M., Young, S.M.M., Quinn, R., Grunthaner, P., Wen, X., Weilert, M., Cable, C.A., Fisher, A., Gospodinova, K., Kapit, J., Stroble, S., Hsu, P.-C., Clark, B.C., Ming, D.W. and Smith, P.H. The MECA wet chemistry laboratory on the 2007 phoenix mars scout Lander. Journal of Geophysical Research. 2009, Mar; 114(E3): 10.1029/2008je003084.

-Poster Presentation:
2011 Harvard Psychiatry Mysell Poster Session; Boston, MA
Hsu, P.C., Rathi, Y., Eckbo, R., Nestor, P., Niznikiewicz, M., Thompson, E., Kubicki, M., Shenton, M.E. (March, 2011). Two-Tensor Diffusion Tensor Imaging of Acoustic Radiations in Schizophrenia

Dr. Nicolette Natale

Nicolette Natale

Dr. Nicolette Natale is a physician, with a background in Psychology, General Medicine, and English Literature, combining her expertise to provide readers with the most accurate, easy-to-understand, and comprehensive information regarding healthcare. She received her Doctorate in Osteopathic Medicine from Nova Southeastern University, and her bachelor’s in English Literature and Psychology from the University of Miami. Dr. Natale seeks to empower individuals with knowledge, fostering a greater understanding of holistic health and encouraging a proactive approach to well-being