10 Consumables That Dehydrate You Fast (and 10 More That Rehydrate You)
Dozens of studies show how staying hydrated protects against heat injury and improves athletic performance, including boosting your muscular strength and endurance. Yet in your rush to get hydrated so you can push harder in your next sweat session, are some of the "hydrating" beverages you're sipping doing the exact opposite? Some foods and drinks can actually zap your body's hydration levels and leave you more dehydrated than before. Today, we'll explore the top 10 foods that cause dehydration — plus specific drinks and foods that actually hydrate you before the gym.
Dehydration Triggers: 10 Foods and Drinks to Avoid
Not all foods and drinks are alike. If you're trying to maintain optimal hydration levels, you may want to reduce or eliminate your intake of the following drinks that cause dehydration and foods that cause dehydration.
5 Drinks That Cause Dehydration
1. Fruit Juice
Some juices may have a positive — yet small — impact on athletic performance. For example, limited studies suggest that beetroot juice may boost your levels of nitric oxide, which in turn may enhance your endurance during long-distance exercises.
Unfortunately, the same can't be said of more commonly drunk fruit juices like orange juice, apple juice, or even "superfood" juices like pomegranate juice.
Most of these juices are very high in sugar. Foods that are high in sugar have a similar effect as salt on your body's cells — excess sugar draws water out of your cells, thereby dehydrating you. This problem is compounded if you're an athlete with diabetes. Your kidneys, already overstressed with an imbalance between sugar and insulin, can't keep up with all the sugar in your bloodstream. That sugar then gets flushed through excessive urination, speeding up how quickly you become dehydrated.
2. Coffee and Other Caffeinated Drinks
Caffeine has a well-established diuretic effect because it interferes with various sensory nerves, as well as your ability to reabsorb sodium. It may also cause you to urinate more often by boosting blood flow to your kidneys.
Specifically for coffee, there is also its well-known effect of causing most people to need to run to the bathroom for a bowel movement (one study found that a cup o' joe causes the average person to need a bowel movement within half an hour after drinking the coffee).
This may be due to coffee's stimulating effects on your colon and other organs in your digestive system. Bowel movements, just like urination, speed up how quickly your body loses water.
3. Coconut Water
The market for coconut water has jumped by billions of dollars in the past few years, in part due to savvy marketing about its health benefits. But dietitians warn that it's not as healthy as coconut beverage companies claim, noting that drinking it too often can actually have harmful effects on your body.
One common claim is that the electrolytes in coconut water help to hydrate you. However, researchers have found that coconut water is actually less hydrating than plain tap water.
We wouldn't recommend getting drunk before hitting the treadmill, although some novel research suggests that the antioxidants in 0% alcohol beer may have a positive but limited effect on your health. Unfortunately, most systemic, peer-reviewed studies make it clear that beer has a largely negative effect on most markers of athletic performance and overall wellness.
Similarly, while research suggests that moderate wine intake can have a positive effect on your disease risks due to its antioxidant levels, you'd be better off taking an antioxidant supplement (such as Tiger Fitness' resveratrol supplements, which is the active antioxidant in wine).
Overall, the problem with beer, wine and other alcoholic beverages is due to the alcohol itself. Alcohol is a potent diuretic, causing your body to flush itself of water as it struggles to get rid of the toxins created when your liver and other organs metabolize the alcohol.
5. Detox Teas
Detox teas are very popular among fitness and wellness enthusiasts, but most of their ingredients are either unproven or rely on very small, unreliable research studies. And while they're marketed as being healthy, they typically work through one main mechanism: Increasing how your body excretes waste and water, thus purportedly "flushing" your body of toxins.
Doctors warn that this can then lead to not only dehydration but also unhealthy imbalances in your electrolyte levels (which further sabotages your athletic performance).
5 Foods That Cause Dehydration
This summer veggie might be a popular grilling item at your next backyard BBQ, but be careful about eating too much. While asparagus contains many healthy vitamins, minerals, and plant compounds, it also has a strong diuretic effect and triggers excessive urination.
2. Keto Foods
If you follow a high-protein, low-carb diet and enjoy keto foods (whether they're whole foods, or packaged snacks and prepared meals), be careful. Dehydration is the most common symptom experienced by those on a ketogenic or keto-style eating plan, with dehydration symptoms showing up within the first four weeks of going low carb.
That's because the glucose in carbohydrates helps your body to hold and store water. No carbs? Less water. This is why the fast weight loss often seen in low-carb diets is typically attributed to losing water weight.
3. Salty Foods
Whether it's fast-food fries, a well-season steak, or a bag of potato chips, watch out for salty foods. Most Americans eat nearly double the amount of salt they should be eating, and all that sodium dehydrates you by pulling water out of your cells and tissues.
4. High-Fiber Foods
Fiber has many benefits, including improving your digestion and gut health. However, eating too much fiber or taking too many fiber supplements causes your body to pull water out of your digestive tract and bowels. This may lead to dehydration.
More is not always better. Recommended fiber intake varies by gender:
- Women should get approximately 25 grams of fiber a day
- Men should get approximately 38 grams of fiber a day
5. Fatty Fish
The omega-3 essential fats in fatty fish like salmon and tuna bring many health benefits. But just like with fiber, excessive intake can lead to some unwanted side effects. The most commonly experienced symptom of eating too much fatty fish or taking too many fish oil supplements is digestive problems, including gas and diarrhea. The latter is a prominent cause of dehydration for many adults.
To avoid the dehydrating effects of fish oil and fatty fish, aim for approximately two servings of fish a week or a daily fish oil supplement that contains approximately 250-500mg of EPA and DHA total.
10 Surprising Drinks and Foods That Hydrate
Now that you know what dehydrating foods and drinks to be aware of, get rehydrated and boost your athletic performance with these 10 drinks and foods that hydrate you:
- Watermelon: True to its name, it's high in water (plus it's rich in healthy lycopene)
- Sports drinks — not to be confused with energy drinks — if you've been working out for 60 minutes or longer
- Electrolyte supplements, whether in powdered form or as a pre-mixed beverage, help your body to rehydrate faster than plain water
- Leafy veggies like spinach, celery, and lettuce, which are nearly 90% water and very nutritious
- Milk may improve exercise recovery and rehydrate you better than a sports beverage
- Pasta — recommended by the American Council on Exercise as an ideal post-workout recovery meal — and is nearly 70% water
- Bone broth (it's not only mostly water, but it's also high in compounds like glycine and collagen that boost workout recovery, reduce inflammation, and protect your muscles and joints)
- Yogurt, which is not only high in water but also rich in calcium and protein to fuel your workouts
- Grapefruit, thanks to being high in water and also great for maintaining a healthy body weight
- Cottage cheese — it's not only hydrating but also contains potent levels of minerals, B vitamins, and protein for faster workout recovery and a healthier metabolism
Some of the above drinks that hydrate and foods that hydrate may already be on your radar. Others, especially the foods that cause dehydration and the drinks that cause dehydration, may be surprising. Use this guide as you meal plan this week, and work on integrating more hydrating meals into your routine.