No evidence of dehydration with moderate daily coffee intake: A counterbalanced cross-over study in a free-living population.
Key takeaways: The caffeine in coffee gives it diuretic effects, meaning it causes your body to pass more urine. But these effects are too mild to cause dehydration, especially if you're a regular coffee drinker. Coffee may even be hydrating for some people, because it contains a lot of water.
Here is one more reason to enjoy that morning cup of joe: “Coffee counts toward your daily water intake,” says Lauren DeWolf, MS, RD, a registered dietitian with Sharp Rees-Stealy Medical Centers. The water in coffee, tea and other caffeinated beverages helps us meet our daily fluid needs.
For approximately every 100 milligrams of caffeine you consume – for instance, the approximate amount in one cup of coffee or two cups of black tea – you should drink an additional cup of water to compensate for the drug's diuretic effect.
Research shows that milk is one of the best beverages for hydration, even better than water or sports drinks. Researchers credit milk's natural electrolytes, carbohydrates, and protein for its effectiveness.
Caffeine is a stimulant, which is why you feel jittery. More than 400 milligrams of caffeine is too much. Drink lots of water, take a walk, practice deep breathing and wait it out.
You might have an electrolyte imbalance: Electrolyte imbalances are one of the most common reasons you might feel dehydrated even after drinking tons of water: “Sometimes if we drink a lot of water but we don't take in enough fruits and vegetables, our electrolytes—sodium, potassium, magnesium, chloride, etc.
Coffee, tea, soda, and alcohol are drinks that people associate with dehydration. Alcohol is a diuretic, which removes water from the body. Drinks such as coffee and soda are mild diuretics, although they can have dehydrating effects on the body.
As a chemical, caffeine increases production of urine, which means caffeine is a diuretic. But most research suggests that the fluid in caffeinated drinks balances the diuretic effect of typical caffeine levels. High doses of caffeine taken all at once may increase the amount of urine the body makes.
With beginning symptoms of dehydration, you can rehydrate by consuming fluids that contain electrolytes, such as sports drinks or oral rehydration solutions. There are also foods available that have a high water content, such as fruits and vegetables. These will also help with rehydration.
Caffeine as a stand-alone substance will not promote weight gain, as it contains very few calories. Things like black coffees and caffeine supplements can actually do the opposite and encourage weight loss through metabolism boosting and appetite suppressing effects.
In general, however, it usually takes about two hours for your body to rehydrate fully after drinking a significant amount of water. As for how you should rehydrate, water is the best choice. Sports drinks, such as Gatorade, can be helpful for athletes who need to replenish electrolytes.
According to a recent study from the Journal of Strength and Conditioning Research, your body can alleviate mild dehydration in 45 minutes with 20.3 oz (600ml) of water.
Juice and soda are not only less hydrating, but offer extra sugars and calories that won't fill us up as much as solid foods, explained Majumdar. If the choice is between soda and water for hydration, go with water every time.
Gatorade, because of its electrolyte content, helps to restore the lost electrolytes and keep a person hydrated, during intense activity. It can also replace electrolytes, during times of illness, such as stomach viruses.
Caffeine levels peak about one hour after ingesting and can stay high for a few hours. Approximately six hours after ingesting caffeine, half of the caffeine in your body is still in your system. Ten to 12 hours after ingesting, caffeine is typically cleared from your body's bloodstream levels.
Healthy adults shouldn't consume more than 400 milligrams (mg) of caffeine per day. That's equal to about four 8-ounce cups of brewed coffee or 10 cans of cola. Teens should limit their caffeine intake to less than 100 mg per day (one 8-ounce cup of coffee or about two cans of cola).
Water. An effective way to get rid of your jitters is to flush out your system with water. Drinking water will decrease the effects of caffeine in a relatively short time.