Is It Better to Eat Hot Food in the Summer? Here's What the Science Says

We've all been there: It's a swelteringly hot day and you've been sweating like a dog, so when it comes to mealtime, you instinctively reach for the obvious.

A steaming hot bowl of soup.

If that scenario seems bizarre to you, think again: Around the world, the natural thing to do when it's hot out is to eat something hot (as in temperature, though a little spicy heat doesn't hurt either).

In Vietnam, it's a bowl of pho. On the Korean Peninsula, the cure for heat is any number of piping hot broths. In Mexico, hot and spicy dishes like tamales are the answer to hunger pangs even if there's a blazing sun outside. And in China, "refreshing" means a cup of hot water.

To an American, even a well-traveled one with a daring palate, it can all seem ... odd.

"What sticks out to me is the insistence, in many corners of Asia, on drinking very hot water whatever the weather," says Matt Gross, former Bon Appetit editor, New York Times Frugal Traveler, and consultant for the Apple+ series Omnivore. "It’s done for historical and health reasons, and I kind of love it in the winter, when the heat gives [the water] a sweetness, but when summer temps hit the 90s I can’t quite handle it."

How Your Brain Affects Your Palate

Clinical psychologist and registered dietitian Supatra Tovar says that there are both psychological and physiological reasons why eating hot foods in the summer can make sense.

"Psychologically, cultural norms and traditions play a significant role," she says. "People may associate certain foods with comfort and familiarity, and these foods often transcend seasonal variations."

In other words, the mind can be a more powerful force than even the sun—and you might see evidence of that in the Chinese insistence on drinking hot water even on the hottest days.

In traditional Chinese medicine, maintaining a balance of yin and yang is considered key to keeping healthy. In particular, yang, associated with "hot" energy, is seen as critical to properly functioning internal organs, and hot water is seen as an important way to maintain that internal energy balance. That was reinforced in the 1930s, when the Nationalist government of China rolled out nationwide health campaigns that encouraged people to drink warm water, which was believed to be cleaner, instead of cold water. The communist government repeated this message with its own public health campaigns in the 1950s. These educational efforts were so successful that boiling water is a given almost anywhere you can find a water dispenser in China even today, as the idea that hot water's the healthy option has become internalized over generations of Chinese.

The general idea is the same in places like South Korea, where age-old sayings encourage people to fight the heat by eating hot foods, and basically anywhere else where it's considered normal. If a belief has been ingrained in a person by their culture from birth, then you're not going to shake it out of them just by pointing at a thermometer and giving them a disbelieving look like they just told you the Earth is flat. (It's not, for the record.)

Why Your Body Tells You to Eat Hot Foods in Summer

But there are actual, not-just-in-our-minds reasons to eat hot foods on hot days, as well.

"Physiologically, consuming hot foods can induce sweating, which is the body's natural cooling mechanism," Tovar says. "When you eat hot foods, your body's internal temperature rises, causing you to sweat. As the sweat evaporates, it cools the body down, helping to regulate your internal temperature in hot weather."

That's backed up by a leading neuroscientist who's published studies on thermoregulation — the body's mechanisms for keeping itself not too hot and not too cold. The scientist, who asked not to be quoted or named in this story, noted that hot foods would activate thermoreceptors in the mouth, triggering more of a response in the body to do what it does to lose heat, which is to sweat.

Indeed, a 2012 study published in the international physiology journal Acta Physiologica (and not one the scientist was involved with) found that participants who drank warm water and then undertook physical activity shed more heat than those who drank cold water, probably because the thermoreceptors in the stomach and esophagus told the body it didn't have to sweat as much when they were doused in an icy cold beverage, whereas quaffing warm water told them it was OK to sweat away.

But, you ask, wouldn't ingesting a big bowl of hot ramen actually raise your body temperature?

No, not really, the scientist says. Because the human body already contains a lot of fluids (nine gallons in an average woman, 11 gallons in an average man), one meal isn't going to appreciably change your core temperature. Think about it: If you have a full ice bath going, you're not going to turn it into a scorching stew just by dumping in a single kettle of boiling water.

What About Spicy Foods?

Back to tricking those thermoreceptors: If you can deceive them with actual hot or cold foods and drinks, it stands to reason you could trick them with foods that aren't actually hot, too, right? That's what happens with spicy foods, which the receptors in your mouth scan as heat-hot.

"One of the truly cool things about chili peppers is how they trick your body into thinking it’s being burned” Gross says. "Their active chemical, capsaicin, bonds with a receptor in your body called TRPV1, which evolved to detect temperatures over 140°F. So when they come in contact, your brain reacts, sending signals to trigger cooldown mechanisms throughout your body—namely, flushing and sweating. There’s no damage going on, but your brain doesn’t know that! It’s just a happy coincidence, or an unhappy one, depending on how you feel about spice."

The result?

"In cultures where spicy food is normal, it tends to be even more popular when temperatures rise," he says. "If you ask people why, they’ll often say that because chiles make you sweat, and sweating cools you off."

Why Do You Crave Cold Foods in Winter?

But what about the other end of the spectrum, how some people like to eat cold foods when it's chilly out?

"Growing up in Colorado, particularly during the winters, I observed how ice cream was enjoyed year-round despite the cold temperatures," Tovar says. "Walking the streets of Breckenridge, it wasn’t uncommon to see people savoring ice cream cones even as they were bundled up in winter coats ... taking a break from the slopes to enjoy an ice cream cone or a cold beer. ... This experience highlighted how cultural and regional habits influence our food choices, irrespective of the weather. ... Psychologically, people may crave cold foods like ice cream due to their comforting and indulgent nature, providing a temporary escape from the harsh cold."

So, yes, cultural and psychological associations are just as strong when the mercury dips as when it rises. But, again, there are physiological factors at play here, too.

It's been well-established both by common wisdom and science— and, let's face it, our eyes and mirrors—that winter weight gain is real. As with many animals, we've evolved to crave more foods, especially those that our body can store in our fat cells, as the sunlight fades away and the nights grow colder—after all, in nature, available foods grow scarce in winter, and our brains are still designed to plan on burning the energy stored in our fat cells to make it alive to spring. And the best kinds of foods to pad those cells? The fatty, sugary kinds, like—you guessed it, Chubby Hubby (or insert your own favorite).

"In colder weather, the body may crave higher-calorie foods rich in fats and sugars to generate more body heat and energy," Tovar says. "Ice cream, being high in both fats and sugars, fits this craving perfectly."

As for those ice-cold apres ski beers, alcohol makes you feel warmer by dilating your blood vessels, which means more warm blood hits your skin. In reality, though, that warmth is actually escaping your body and bringing down your core temperature, so it's not a real solution to the cold, though it can be a fun, albeit temporary, one—if done responsibly and while you're wearing clothing appropriate to the weather.

The Takeaway

So what's the ultimate takeaway here? Humans are a weird, quirky, self-contradictory bunch of animals, and we'll find the zaniest solutions to problems that aren't really problems. So, as long as you're not hurting yourself, go ahead and eat that blazing hot chile stew—or ice pop—for the August clambake. Wolf down that ice cream sundae—or pho—for New Year's. It's all good.

"As human beings, we often think we can outsmart nature—that we can live outside of it—and we are probably subconsciously trying to challenge our environment," Gross says. "'It’s snowing? Give me ice-cold vodka! It’s 99 degrees with 99% humidity? Bring on the Sichuan hot pot.'"