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Summer is here in full swing, and with it comes rising temperatures. While you should be focused on staying hydrated all year long, it’s especially important during the summer because you may be sweating and your body is working harder to cool down.
Drinking water is optimal, and there are plenty of electrolyte drinks on the market. But did you know that the foods you eat could be affecting your hydration levels more than you thought? Instant Hydration conducted a study in May 2026 on the most dehydrating foods you can order, and the results were pretty fascinating. Here are the foods you might want to avoid so you can stay as hydrated as possible.
Maple Bacon Brussels SproutsThe Most Dehydrating Takeaway Foods
Instant Hydration analyzed 34 popular takeaway orders to determine which leave you thirstiest by looking at four factors: sodium, caffeine, sugar, and water content. “Sodium raises the body’s need for water, as kidneys require fluid to flush out excess salt. Caffeine can increase urine output at higher concentrations. Sugar creates an osmotic effect, drawing water into the gut during digestion. Low water content provides little compensatory hydration,” the study explained. From there, all the takeaway orders were given a score — and those with the highest were deemed the most dehydrating.
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1. Donuts
Shockingly, donuts took the top spot as the most dehydrating food you can order. Why? They have 20.5 grams of sugar, plus they can be quite dry. There’s hardly any moisture in the donut itself (just 24% water content) to offset the effects of the sugar. Donuts are also high in sodium with about 487 milligrams per serving, which also makes you even more dehydrated. A wellness expert from Instant Hydration said, “Your body has a limited supply of water at any given moment. When you eat a donut, your gut pulls water from your bloodstream to dilute the sugar.”
Credit: Photo: Alex Lepe; Food Styling: Kelli Foster
2. Chocolate Brownies
Not too far behind was another sweet treat: chocolate brownies. They contain 40 grams of sugar, nearly double the amount in the donut, and have a water content of just 15% (one of the lowest of all the foods evaluated). While there’s less sodium than the donuts (289 milligrams), the high sugar concentration and low moisture content still makes them easily deplete your fluids.
3. Mozzarella Sticks
Not until third place do we have a savory food, mozzarella sticks, which I found pretty surprising. What’s not as surprising is why it’s so dehydrating. Mozzarella sticks contain 861 milligrams of sodium per serving (one of the highest sodium levels of all the foods tested), and have a water content of 38%. Because they’re so high in sodium and are usually greasy and fried, they can dehydrate you fast. “When you eat mozzarella sticks, your kidneys pull water from your cells to flush out the salt.”
Credit: Photo: Alex Lepe; Food Styling: Janette Zepeda
4. Garlic Naan
Garlic naan took the fourth spot with 810 milligrams of sodium and a water content of 36%. While the naan itself can be a sodium bomb (and is most likely slathered in butter), context is also important here. It’s usually served alongside a rich, creamy, and potentially salty curry, so the entire meal could be very dehydrating.
Credit: Photo: Alex Lepe; Food Stylist: Rachel Perlmutter
5. Chicken Quesadilla
Last but not least is a chicken quesadilla, which has 745 milligrams of sodium per serving. All the elements of the meal contribute to its dehydrating factor: The tortilla, cheese, and seasoned chicken can all be salty, plus the technique used to make the quesadilla draws out even more moisture. If it’s served with sour cream and salsa, as most are, the sodium content only continues to go up. Instant Hydration says the amount of sodium in this meal is “comparable to a fast-food burger.”
Other Dehydrating Foods
The remaining dehydrating foods in the top 10 were as follows: pepperoni pizza, burrito, sausage egg & cheese sandwich, hot dog, wings, and chicken tenders all for their sodium content; french fries and chips & queso brought up the rear for their sodium and dry texture.
I was most surprised by the fact that coffee and tea didn’t even make the top 10. I’ve heard so much talk around how dehydrating these drinks are, but turns out there are far worse things in that department. Instant Hydration noted that “coffee and tea-based drinks sit in the moderate risk tier, with the caffeine acting as a mild diuretic and sugar adding a little to the fluid deficit.”
Ultimately, what’s most important is to make sure that if you are eating any of the above foods, drink water with it to offset the impacts and replenish those hydration levels. As the wellness rep said, when you eat these kinds of foods, “no new water [is] coming in. That’s why you feel tired and foggy after eating. You are dehydrated, not just full. The solution couldn’t be simpler. Drink water with your food. Not soda. Not sweet tea. Water.”
Further Reading
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