When you’re dehydrated, certain foods and drinks can pull even more water out of your cells or force your body to use its limited fluid reserves for digestion. The biggest offenders are high-sodium foods, alcohol, and large amounts of protein or fried food. Avoiding these while you rehydrate can make the difference between feeling better in an hour or dragging through the rest of your day.
Why Salty Foods Make Dehydration Worse
Salt is the single most important thing to limit when you’re already low on fluids. When excess sodium enters your bloodstream, it raises the concentration of dissolved particles outside your cells. Water follows salt through osmosis, so fluid gets pulled out of your cells to balance things out. Your cells literally shrink. Specialized neurons in your brain detect this shrinkage and fire off thirst signals in proportion to how much water your cells have lost.
This means a bag of chips, a bowl of ramen, or a handful of pretzels does the opposite of what your body needs. Instead of water moving into your cells to rehydrate them, it moves out. Some specific foods to skip:
- Soy sauce and teriyaki sauce: Soy sauce is 17 to 18 percent sodium chloride by weight. A few tablespoons on rice can meaningfully shift your fluid balance when you’re already running low.
- Deli meats and cured foods: Salami, bacon, jerky, and smoked fish are preserved with large amounts of salt.
- Canned soups and instant noodles: A single serving often contains over half your daily sodium recommendation, and most people eat the whole can or packet.
- Salted snack foods: Chips, crackers, popcorn, and salted nuts are concentrated sources of sodium with very little water content to offset it.
This doesn’t mean you need zero sodium. In fact, a small amount of sodium paired with glucose actually helps your intestines absorb water more efficiently. Oral rehydration solutions work on exactly this principle, using a 1:1 ratio of sodium to glucose to optimize the transport system in your gut lining. The problem is the large, unbalanced doses of salt in processed and restaurant food, not a pinch of salt in your water.
Alcohol Actively Dehydrates You
If you’re dehydrated because of a hangover, the last thing you want is more alcohol. But even a single drink while you’re dehydrated from exercise, heat, or illness can set you back. Alcohol suppresses the hormone that tells your kidneys to hold onto water. Without that signal, your kidneys send fluid straight to your bladder instead of recirculating it. The result is that you lose more liquid than you took in with the drink itself.
Beer, wine, cocktails, and hard seltzer all have this effect. The higher the alcohol content, the stronger the diuretic push. If you’re actively trying to rehydrate, skip alcohol entirely until you feel recovered.
Fried and High-Fat Foods
Greasy, fried foods are a poor choice during dehydration for a straightforward reason: they’re hard to digest. Fat takes longer to break down than carbohydrates or protein, and the digestion process itself requires water. When your body is already short on fluids, diverting water to process a plate of french fries or fried chicken increases the internal demand for fluid you don’t have.
Fried foods also tend to be heavily salted, compounding the sodium problem. On top of that, slow digestion can cause bloating and nausea, which makes it harder to drink the fluids you actually need. When you’re dehydrated, your stomach is already more sensitive. Light, water-rich foods are far easier on your system.
Large Amounts of Protein
Your body uses extra water to process protein. When you break down amino acids, a waste product called urea is created, and your kidneys need fluid to flush it out. A massive steak or a double scoop of protein powder isn’t ideal when your fluid reserves are low. This doesn’t mean you need to avoid protein entirely, but a protein-heavy meal without plenty of water alongside it can quietly worsen mild dehydration.
Sugary Drinks and Concentrated Sweets
A can of soda or a glass of fruit juice concentrate might seem like a way to get fluids in, but drinks with very high sugar concentrations can actually slow water absorption in your gut. When the sugar concentration in your intestine is much higher than in your blood, water moves toward the sugar rather than into your bloodstream. This is why full-strength fruit juice or energy drinks sometimes cause loose stools or cramping during dehydration, especially in children.
Candy, pastries, and other concentrated sweets have a similar issue. They pull water into your digestive tract without contributing meaningful hydration. If you want something sweet, diluted juice or a piece of whole fruit like watermelon or cucumber is a far better option, since the water and fiber slow sugar absorption.
What About Coffee and Tea?
Caffeine has a reputation as a dehydrator, but the reality is more nuanced. Caffeine is technically a diuretic, meaning it increases urine production. However, most research shows that the fluid in a cup of coffee or tea offsets this diuretic effect at normal doses. If you drink coffee regularly, your body has already adapted and the diuretic effect is even smaller.
That said, if you’re not a regular caffeine drinker, a large dose taken all at once is more likely to increase fluid loss. And caffeine on an empty, dehydrated stomach can cause nausea and jitteriness. So if you’re significantly dehydrated, water or an electrolyte drink is the smarter first choice. Your coffee can wait until you’ve gotten some fluids in.
What to Reach for Instead
The best foods during dehydration are the ones that deliver water, a small amount of salt, and easy-to-digest carbohydrates together. Watermelon, cucumbers, oranges, strawberries, and plain broth all fit this description. Bananas add potassium, which is another electrolyte you lose through sweat and illness. Plain rice, toast, or oatmeal made with extra water are gentle on your stomach and won’t compete with your body for fluid.
For drinking, plain water works for mild dehydration. If you’ve been sweating heavily, vomiting, or dealing with diarrhea, an oral rehydration solution or a sports drink diluted with water replaces both fluid and electrolytes more effectively than water alone. Small, frequent sips absorb better than gulping a large amount at once, especially if your stomach is already upset.