CLOSE
iStock
iStock

We Eat a Lot More When We’re Tired

iStock
iStock

Love it or hate it, sleep is an essential (and substantial) part of your life. When we don’t get enough rest, we start to break down—and so do our eating habits. A new meta-analysis [PDF] published in the European Journal of Clinical Nutrition found that sleep-deprived people ate hundreds more calories per day than they did when they were well-rested.

Researchers at King’s College London pulled data from 11 different sleep and eating studies on a total of 172 people. All of the studies involved an experimental group, in which people were kept awake for part of the night, and a control group, whose participants were allowed to get the sleep they needed. The participants’ energy intake—that is, how much they ate—and output (any physical exertion) were then tracked for the next 24 hours.

Unsurprisingly, sleep-deprived people did not exercise more than the well-rested. But they did eat more, averaging 385 calories over their typical daily intake. They weren’t just any calories, either; participants specifically sought out foods high in fat and protein. Their carbohydrate intake did not change.

What was behind these snoozy munchies? The research team can’t say for sure. Previous studies point to two potential culprits: our brains and our hormones. One 2013 report found that the brains of sleep-deprived people responded more urgently to pictures of fattening food, inspiring cravings even when the participants were full. And even as their snack-lust peaked, the participants experienced a drop in activity in the region of the brain associated with careful decision-making. They really didn’t stand a chance.

Other experiments have found that sleep deprivation can lead to an imbalance in the so-called hunger hormones leptin and ghrelin, which can trick the body into believing that it’s starving.

The takeaway from the latest study, say its authors, is that weight gain is complicated. Diet and exercise are crucial factors, but they don’t operate in a vacuum.

“Reduced sleep is one of the most common and potentially modifiable health risks in today's society in which chronic sleep loss is becoming more common,” senior author Gerda Pot said in a statement. “More research is needed to investigate the importance of long-term, partial sleep deprivation as a risk factor for obesity and whether sleep extension could play a role in obesity prevention."

nextArticle.image_alt|e
iStock
arrow
Animals
Owning a Dog May Add Years to Your Life, Study Shows
iStock
iStock

We've said that having a furry friend can reduce depression, promote better sleep, and encourage more exercise. Now, research has indicated that caring for a canine might actually extend your lifespan.

Previous studies have shown that dog owners have an innate sense of comfort and increased well-being. A new paper published in Scientific Reports and conducted by Uppsala University in Sweden looked at the health records of 3.4 million of the country's residents. These records typically include personal data like marital status and whether the individual owns a pet. Researchers got additional insight from a national dog registry providing ownership information. According to the study, those with a dog for a housemate were less likely to die from cardiovascular disease or any other cause during the study's 12-year duration.

The study included adults 40 to 80 years old, with a mean age of 57. Researchers found that dogs were a positive predictor in health, particularly among singles. Those who had one were 33 percent less likely to die early than those who did not. Authors didn't conclude the exact reason behind the correlation: It could be active people are more likely to own dogs, that dogs promoted more activity, or that psychological factors like lowered incidences of depression might bolster overall well-being. Either way, having a pooch in your life could mean living a longer one.

[h/t Bloomberg]

nextArticle.image_alt|e
iStock
arrow
Live Smarter
Not Sure About Your Tap Water? Here's How to Test for Contaminants
iStock
iStock

In the wake of Flint, Michigan's water crisis, you may have begun to wonder: Is my tap water safe? How would I know? To put your mind at ease—or just to satisfy your scientific curiosity—you can find out exactly what's in your municipal water pretty easily, as Popular Science reports. Depending on where you live, it might even be free.

A new water quality test called Tap Score, launched on Kickstarter in June 2017, helps you test for the most common household water contaminants for $120 per kit. You just need to take a few samples, mail them to the lab, and you'll get the results back in 10 days, telling you about lead levels, copper and cadmium content, arsenic, and other common hazardous materials that can make their way into water via pipes or wells. If you're mostly worried about lead, you can get a $40 test that only tells you about the lead and copper content of your water.

In New York State, a free lead-testing program will send you a test kit on request that allows you to send off samples of your water to a state-certified lab for processing, no purchase required. A few weeks later, you'll get a letter with the results, telling you what kind of lead levels were found in your water. This option is great if you live in New York, but if your state doesn't offer free testing (or only offers it to specific locations, like schools), there are other budget-friendly ways to test, too.

While mailing samples of your water off to a certified lab is the most accurate way to test your water, you can do it entirely at home with inexpensive strip tests that will only set you back $10 to $15. These tests aren't as sensitive as lab versions, and they don't test for as many contaminants, but they can tell you roughly whether you should be concerned about high levels of toxic metals like lead. The strip tests will only give you positive or negative readings, though, whereas the EPA and other official agencies test for the concentration of contaminants (the parts-per-billion) to determine the safety of a water source. If you're truly concerned with what's in your water, you should probably stick to sending your samples off to a professional, since you'll get a more detailed report of the results from a lab than from a colored strip.

In the future, there will likely be an even quicker way to test for lead and other metals—one that hooks up to your smartphone. Gitanjali Rao, an 11-year-old from Colorado, won the 2017 Young Scientist Challenge by inventing Tethys, a faster lead-testing device than what's currently on the market. With Tethys, instead of waiting for a lab, you can get results instantly. It's not commercially available yet, though, so for now, we'll have to stick with mail-away options.

[h/t Popular Science]

SECTIONS

arrow
LIVE SMARTER
More from mental floss studios