3 Effects Of Alcohol While Fasting

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Alcohol While Fasting

Can you drink alcohol while fasting? It’s probably one of the few questions many seem to ask when the topic of intermittent fasting pops up.

Intermittent fasting is not a new thing. This pattern of eating has been practiced throughout human history and is common in most religions.

Today, it is a popular lifestyle for many wanting to lose weight, improve brain function and boost their immune system. The main rule for intermittent fasting is to stick to a specific fasting and eating window. This means no food during fasting hours and only liquids allowed.

One particular advantage of intermittent fasting is there are no specific food rules. But with only liquids allowed and no strict food intake, could alcohol be consumed?

Let’s break down all the details you need to know about alcohol, intermittent fasting, and whether or not you can drink alcohol while fasting.

Background On Alcohol

You likely enjoy a drink of alcohol to have fun and socialize with your peers. Other times drinking helps you relax and alleviate feelings of stress.

There are even health benefits of alcohol, such as a reduced risk of heart disease and reduced insulin resistance1,2. Whatever your reasons, alcohol is great to enjoy for a drink or two.

However, alcohol can also play a large role in your weight management. While moderate alcohol use may offer some health benefits, heavy drinking — including binge drinking — has no health benefits.

Alcohol And Your Body

The main ingredient in alcoholic beverages is ethanol, and it is the substance that makes you drunk.

Once swallowed, alcohol enters your stomach and small intestine, where small blood vessels carry it to the bloodstream. Approximately 20% of alcohol is absorbed through your stomach, and most of the remaining 80% is absorbed through the small intestine3.

Your bloodstream distributes alcohol quickly to your brain, kidney, lungs, and liver. On average, your liver takes an hour to break down one unit of alcohol. The effect on your body depends on the following4:

  • Age
  • Gender
  • Weight
  • How quickly your body turns food into energy.
  • The amount of food you’ve eaten.
  • The strength and type of alcohol.
  • If you are taking medications.

Can You Drink Alcohol While Fasting?

Anyone who does intermittent fasting generally knows the three safe drinks for fasting: water, black coffee, and tea. These drinks don’t contain any calories. Therefore, they can be consumed during fasting hours when no food and caloric drinks are allowed.

Alcohol just happens to be one of the more calorie-dense macronutrients. This means drinking any type of alcohol during your fasting window will break your fast.

Intermittent Fasting And Alcohol

Intermittent fasting has been linked to many other health benefits like reducing inflammation and improving heart health5,6.

If you are using fasting as a way to lose weight, drinking alcohol can slow down your progress. There is a study7 that shows alcohol can reduce your body’s ability to burn fat for as long as five hours after eating.

Drinking alcohol could then cause you to store more fat. Since your body considers alcohol a toxin, it tends to metabolize it before everything else.

That means that other nutrients, especially fat, may be pushed to the back of the line. Some of this fat may get stored and may lead to weight gain over time. Also, alcohol can make you hungrier and possibly overeat8.

Not to mention, drinking too much alcohol frequently can promote inflammation, overwhelm your liver, and counter many health benefits from fasting9,10,11.

Full vs Empty Stomach

If there is no solid food in the stomach or intestines, the alcohol will come into contact with your intestinal walls more easily and pass quickly into the blood. All the alcohol in one drink may be absorbed within 30 minutes.

If your stomach is relatively full, the alcohol will stay there longer. The absorption process will be slower and may take up to 90 minutes.

While drinking with an empty stomach may sound promising in flushing alcohol out quickly, it is anything but. Alcohol may be absorbed into your system faster, but this can make you become drunk quicker.

Alcohol also inhibits fat-burning, ketosis, and autophagy. This is why it is recommended not to have it during your fasting period.

Alcohol can be consumed in moderation during your eating window. If you do so, try to keep the time gap between alcohol consumption and your fasting periods as big as possible so as not to negate the effects of intermittent fasting.

How Alcohol Breaks Your Fast And Invalidates Its Benefits

1. High In Calories

Alcohol is known as ethanol, and it’s calorie-dense (7 calories per gram). A shot of liquor can run anywhere from 80 to 100 calories. A beer is about 150 calories, while a glass of wine runs around 120.

Even the cocktail mixers aren’t harmless. Cocktail recipes often call for mixes that top out at 300 or more calories per serving because of the added sugar content. Consistent high-calorie intake will sabotage your weight loss efforts.

2. Burned First For Fuel

As mentioned, alcohol will be dispensed from your body first. About 20% of the calories you consume from alcohol are used up right away. The rest goes to digesting and metabolizing it, creating more hunger pangs between meals (which can lead to overeating)4.

Alcohol also suppresses fat-burning enzymes in your liver. So any fat that is consumed with alcohol gets stored rather than being burned as fuel.

3. Excess Alcohol Prevents Autophagy

Autophagy is one of the foremost benefits of intermittent fasting. It is the process by which your cells discard their waste products and other dysfunctional components. Autophagy is highly protective against degenerative diseases, aging, and even cancer12.

Excessive alcohol can inhibit autophagic activity during intermittent fasting. Autophagy is inhibited by oxidative stress and inflammatory mediators, which occur after chronic intensive alcohol consumption13. In other words, if you frequently drink, you do not express as many of the cellular components necessary for autophagy.

In addition, a single night of binge drinking may impair protein-clearing pathways like autophagy in brain cells.

Breaking A Fast With Alcohol

If you’re going to drink during an intermittent fasting diet, be careful about breaking your fasts with alcohol. You’re probably better off eating something first or at least having your drink alongside a large meal.

When you eventually drink, you should keep your alcohol intake in check. Moderate intake is defined as no more than one drink per day for women and no more than two per day for men14.

While intermittent fasting doesn’t have strict rules for food and beverage intake, some alcohol choices are healthier than others and less likely to counteract your dietary regimen.

Healthier options include dry wine and hard spirits, as they’re lower in calories. You can sip these on their own or mixed with soda water.

To limit your sugar and calorie intake, avoid mixed drinks and sweeter wines.

Alcohol And Weight

If your drink alcohol and gain weight, it does not mean your metabolism is failing you. Weight gain related to alcohol consumption comes from general overconsumption linked to satiety.

The calories you consume through alcohol will not affect your appetite because it does not give you feelings of fullness. Not to mention, intoxication can encourage overeating and a lack of dietary restraint.

A research conducted on mice showed that the area of the brain responsible for eating was directly affected and excited by ethanol. These mice respond very strongly to its exposure by overeating for several hours afterward. Researchers believe a similar reaction happens in humans15.

Best Practices For Drinking Alcohol While Fasting

Drinking daily is clearly not a good idea, and alcohol negatively affects your fast. But this does not mean you can’t enjoy alcohol altogether.

If you ever need an alcohol break, here are some of the best practices you can implement:

1. Only have alcohol during your eating window.

Alcohol can disrupt your sleep quality, and poor-quality sleep can lead to weight gain16.

By keeping your drinks to your eating window, you will ensure that you’re not drinking too close to bedtime and disrupting your sleep.

2. Avoid drinking anything with added sugars.

Sugar is one of the highest offenders to insulin production and shifting your body into fat-storing mode. Try sticking to cocktails made with sparkling water, muddled fruit, or soda water. You may also opt to drink wine.

3. Limit drinking for occasions.

There appears to be an increased level of the stress hormone with drinking alcohol17.

If you’re drinking wine or a cocktail in response to a stressful day, this could lead to poor quality sleep from possibly elevated stress hormone levels.

Instead, you can try doing alternative stress relievers and keep the glass of wine for a fun dinner with your loved ones or friends.


Alcohol will break your fast because it contains calories. While there is no direct rule to stop drinking alcohol entirely, you must ensure that you’ve eaten enough food before trying to consume any alcoholic beverages. Whether or not you are fasting, if you drink a light to moderate amount and are healthy, you can consume alcohol as long as you drink responsibly.


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2 Facchini F, Chen YD, Reaven GM. Light-to-moderate alcohol intake is associated with enhanced insulin sensitivity. Diabetes Care. 1994 Feb;17(2):115-9. doi: 10.2337/diacare.17.2.115. PMID: 7907975.

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13 Li Y, Ding WX. Adipose tissue autophagy and homeostasis in alcohol-induced liver injury. Liver Res. 2017 Jun;1(1):54-62. doi: 10.1016/j.livres.2017.03.004. Epub 2017 Apr 26. PMID: 29109891; PMCID: PMC5669268.

14 Center for Disease Control and Prevention. (2022, April 19). Dietary Guidelines for Alcohol. https://www.cdc.gov/alcohol/fact-sheets/moderate-drinking.htm#:~:text=To%20reduce%20the%20risk%20of,4

15 Cains, S., Blomeley, C., Kollo, M. et al. Agrp neuron activity is required for alcohol-induced overeating. Nat Commun 8, 14014 (2017). https://doi.org/10.1038/ncomms14014

16 Beccuti G, Pannain S. Sleep and obesity. Curr Opin Clin Nutr Metab Care. 2011 Jul;14(4):402-12. doi: 10.1097/MCO.0b013e3283479109. PMID: 21659802; PMCID: PMC3632337.

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