Hydration is the process of ensuring the body has enough water. Drinks that may result in dehydration can include alcoholic, caffeinated, and sugary beverages.

Hydration is important for all the cells in the body, which use water for numerous functions like removing waste and taking in nutrients.

While the liquid component of many drinks, and even certain foods, can help hydrate the body, quite a few liquids can have the opposite effect.

Drinks and ingredients that act as diuretics, which are substances that increase urine production, may have a dehydrating effect if a person does not take care to balance them with adequate hydration from other sources.

Drinks containing high amounts of alcohol, caffeine, and sugar are most likely to perform as diuretics in the body and promote dehydration. Below is a list of drink types that fall within these categories.

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Alcohol acts as a diuretic in the body. This means it encourages the body to remove more fluid through urine than normal. As the body processes alcohol, it encourages extra urination to help remove alcohol and its waste products from the body quickly.

While drinking extra liquids may generally lead to more frequent urination, a diuretic liquid such as alcohol will encourage the body to expel even more liquid.

If a person does not get enough hydration alongside their alcohol intake, the alcohol may cause dehydration. Generally, the higher the alcohol content of a beverage, the more dehydrating it can be.

For example, research from 2017 found that in elderly men at risk of dehydration, moderate consumption of high alcoholic beverages such as wine and liquor caused a diuretic effect. Beverages with lower alcohol content, such as beer, did not appear to have this effect.

Additionally, a 2018 study notes that alcohol may reduce a compound called vasopressin in the body. Vasopressin is an anti-diuretic that helps the body retain water. The reduction of vasopressin may prevent the body from retaining the water it needs, thus promoting dehydration.

Beer and cider

Beer and cider have lower alcohol contents than other alcoholic drinks and are less dehydrating. The alcohol content of beer can vary widely but typically ranges from 2–8% alcohol by volume (ABV). Cider, or fermented apple juice, has an ABV of around 5%.

The body may tolerate a moderate intake of beer without experiencing dehydration.


Wine generally has a higher alcohol content than beer and cider, which may contribute to the likeliness of more frequent urination and dehydration. The alcohol content of wine can vary from about 10–20% ABV.

Wine also tends to have a higher sugar content, which may further contribute to the dehydrating effects.


Liquor tends to have a much higher alcohol content and significantly less liquid than other alcoholic drinks, which can contribute to dehydration. Liquor’s ABV varies widely and can be as high as 95%.

Some people may also pair liquor with other drinks and ingredients in mixed drinks. Drinks with high sugar content or caffeine combined with liquor in mixed drinks can make symptoms worse for some.

Caffeine can act as a mild diuretic in some instances. A small amount of caffeine may not be an issue for most people, though increasing caffeinated beverages may contribute to overall caffeine intake.

Research from 2017 indicates that low levels of caffeine ingestion do not cause dehydration. Participants who consumed over 500 milligrams (mg) of caffeine daily showed disruptions in fluid balance from the diuretic effects of coffee.

Significantly high levels of caffeine intake may contribute to dehydration by stimulating the body to release more liquid than usual.


Coffee generally has about 95–165 mg of caffeine per 8-ounce (oz) cup.

Drinking 2–3 cups of coffee a day may be an acceptable practice to maintain moderate coffee consumption. An increased intake of coffee may cause a diuretic effect that promotes dehydration.


While tea tends to have less caffeine than coffee, increased tea consumption can still contribute to the total amount of caffeine a person has each day and yield dehydration.

Additionally, many teas may also contain high levels of sugar from sweetened milk, sugars, or syrups, which may not be the most hydrating for quenching thirst.


Soda often contains caffeine and high amounts of sugars. The consumption of a cold soda may feel refreshing at first but likely will not satisfy a person’s thirst in the long run.

Research from 2016 found that the sensation of a cool, carbonated beverage makes people think the beverage quenches thirst better. This can lead to drinking less additional liquid after having a drink such as a soda, which could make the effects of dehydration worse.

Energy drinks

Energy drinks may contain a combination of dehydrating ingredients. They generally contain high levels of caffeine and sugar and may contain other added ingredients that stimulate the kidneys and act as a diuretic.

Experts believe that too much sugar may make dehydration and other symptoms worse. This is likely because of the interaction of sugar and water within the cells. Higher sugar intake causes the cells in the body to transfer more water and increase urination.

Lower levels of hydration in the body decrease the volume of the cells, which may impact a person’s blood sugar.

When a person has very high blood sugar, their body may borrow water from other areas to balance out the volume in the cells. This can influence cellular hydration. Higher blood sugar may also cause the body to urinate more to get rid of this excess sugar, which can influence dehydration. The extent of these effects and how long they last may vary.

A 2020 study notes that dehydration may increase glucagon, a hormone used to maintain glucose or sugar levels in the blood. This can be an indicator of higher blood sugar.

Dehydration may also impair blood sugar response in some, such as those with type 2 diabetes. Research from 2017 found that people with diabetes who had 3 days of low water intake had an impaired blood glucose response.

Another study from 2018 found that this impaired response does not occur in healthy individuals, but that mild dehydration does cause some glycemic reactions in the blood, similar to diabetes.

It is important to note that having higher blood sugar from consuming very sugary drinks may encourage the body to eliminate the excess sugar but may not necessarily cause dehydration.

Those who seek to reduce their consumption of sugary drinks may wish to avoid:

  • sweetened fruit juice
  • fruit cocktails
  • sweetened tea and soda
  • energy drinks
  • coffee and tea drinks with added sugar or syrup
  • mixed drinks
  • highly sweetened athletic drinks

The following general tips may help a person stay hydrated and avoid consuming too many dehydrating drinks:

  • drinking eight 8-oz glasses of hydrating liquids such as water per day
  • carrying a water bottle and regularly drinking throughout the day
  • eating extra foods that have high water content, such as soups, stews, fruits, and vegetables
  • decreasing the consumption of alcoholic, highly caffeinated, and sugary beverages when feeling thirsty
  • ensuring the body is properly hydrated before and while drinking alcohol
  • understanding personal alcohol and caffeine tolerance levels to avoid overconsumption
  • diluting sugary drinks with extra water for a bit of flavor with more hydration

Additionally, making changes to the diet to replace dehydrating drinks may help. Over time, these changes can become habits and help correct dehydration issues.

Some examples of hydrating drinks include:

  • water
  • infused water, made by adding ingredients such as basil, lemon, or cucumber to the water for a period of time
  • coconut water
  • sports drinks containing electrolytes
  • herbal teas and caffeine-free infusions
  • sparkling water

Proper hydration is essential for the body to function correctly. While most drinks and high-liquid foods will provide water for the body to use and stay hydrated, some drinks may act as diuretics having the opposite effect. This can make issues such as dehydration worse.

Taking steps to avoid the overconsumption of alcoholic, caffeinated, and sugary beverages may help a person avoid dehydration. Water, electrolyte sports drinks, and certain herbal teas are better options to remain hydrated.