We’ve officially reached the dog days of summer, so if you’re panting for relief in this stifling heat, sipping on a big, icy glass of water and doubling down on hydrating fruits and veggies is definitely a good idea. But staying cool and comfortable isn’t just about a good offense. On extra-hot days, it’s also important to play defense with your diet, steering clear of diuretic foods and drinks (which flush fluids from your body quickly) and dehydrating high-sodium eats.
“For the most part, your body tells you what it wants, especially in the heat of a summer’s day,” says dietitian Wendy Lord, R.D., a consultant for Sensible Digs. “We generally start craving cooler, refreshing foods rather than those that are likely to make us more dehydrated.”
The thing is, it’s not all that uncommon that we set ourselves on auto-pilot, ignoring or misunderstanding the signals our body sends us, according to Lord. (This explains the phenomenon of why we mistake thirst for hunger and reach for a snack instead of refilling our water bottles.) Plus, salty foods like burgers, dogs, and potato chips are practically synonymous with backyard barbecues, making it easy to exceed the recommended 2,300 milligrams of sodium per day in just one meal, Lord points out.
“The problem with having too much salt in the body is that it draws water out of the tissues and causes dehydration,” she explains. The solution isn’t as simple as eliminating salt, though. Sodium and chloride are both important for maintaining the water balance in the body and ensuring your muscles contract and relax normally, Lord says. “When you’re losing salt through your sweat, it’s important to replace it,” she explains. “The trick is to not go overboard.”
Ahead, we break down which foods and drinks to avoid on hot days, plus what you should reach for instead.
1. Caffeinated Iced Coffees & Teas
When the temps are flirting with triple digits, a hot, steamy beverage probably doesn’t hold much appeal. But caffeinated iced coffees and teas can actually be worse for you from a hydration standpoint.
You see, caffeine is a diuretic, which means it makes you urinate more frequently, and iced drinks are even more diuretic than hot drinks, says dietitian Kelsey Butler, R.D., of Coastal Dream Life. Say what? “This is because ice actually uses bodily fluids to melt it,” Butler explains. If you’re trying to stay hydrated on a hot day, it’s best to avoid caffeinated drinks altogether, but especially the iced ones. Rough, we know.
Of course, you can always go for a decaf coffee or caffeine-free tea. Or, you can opt for a healthy smoothie (here are some green smoothies that dietitians love). “[Smoothies] are packed with vegetables and fruit that provide fluid as well as fiber, vitamins, and minerals,” Lord says.
Not only is soda high in sugar, but it’s also a diuretic and the fizziness can trick you into thinking your thirst has been quenched prematurely, according to dietitian Bill Bradley, R.D., CEO of Mediterranean Living. Research shows that the mouthfeel of carbonated beverages makes it seem like you’re quenching your thirst more than you actually are, which may lead you to drink less than you truly need.
That’s why it’s best to drink plain water to hydrate, Bradley says. You can always add fresh fruit for a bit of sweetness. If you’re really craving something bubbly, stick with seltzer—but don’t let the fizziness fake you out!
Whether you’re sipping piña coladas poolside or bringing a cooler full of beer to the beach, heed this warning: Alcohol leads to dehydration, says Lord. “You should always drink a glass of water between alcoholic drinks, but it is even more important on a hot, sunny day,” she urges.
You’ll really want to watch out for drinks like whiskey-sodas, margaritas, and red wine sangrias. That’s because liquors like cognac, brandy, red wine, bourbon, tequila, and darker whiskey have the highest levels of congeners, which are compounds that occur naturally in the distilling and fermenting processes. According to one study published in Current Drug Abuse Reviews, congeners can dehydrate you more quickly.
4. Salty snacks
5. Spicy Foods
If you’re spending time in the heat, ditch the hot sauce, spicy peppers, and hot chicken sandwiches. “Spicy foods temporarily raise your body temperature, making it more challenging to stay cool,” explains dietitian Stephanie Small, M.S., R.D.N., L.D., of Jugofeed. Why make yourself even sweatier than you already are?
Instead, keep things mild with a big salad. “Salads are basically crispy water,” Lord says. “Lettuce, tomato, cucumber, and other vegetables contain water in a framework of fiber.”
She recommends topping your salads with legumes like lentils, chickpeas, or beans, which add some slow-release carbohydrates and protein. You could also include meat, fish, or chicken for protein, as well as avocado, nuts, or seeds for healthy fats. Need some more inspiration? Check out this list of the best and worst things to put on your salad.
Coffee, sodas, and alcohol may be the most known diuretics, but asparagus—as healthy as it is—is also a diuretic, says Small. So, not only does the veggie make your pee smell funny, but it makes you have to go to the bathroom more frequently (research published in the West Indian Medical Journal backs this up).
When planning your next BBQ, consider skipping the grilled asparagus side and opt for bell peppers, onions, and summer squash instead.