It’s time for mistletoe and holly, tasty pheasants, Christmas presents, and…silly science? Yep, every December the BMJ (formerly known as the British Medical Journal) publishes an issue full of quirky research. The science is valid, but the topics are goofy. (In 2013, for example, we learned that among Harry Potter characters, the ability to speak to snakes is heritable.)

In this year’s issue, our favorite BMJ papers explore where weight goes when you lose it, whether men really are idiots, and why the magazines in doctor's office waiting rooms are always annoyingly out of date.

Where does the fat go?

We all know that when you burn fat, you get energy. But there’s more to the equation: When you metabolize a molecule of triglyceride (the most common type of fat in our bodies), you also get carbon dioxide and water. For this study, researchers calculated how much fat ends up as CO2 versus H20. They found that only 16% of the mass of a fat molecule becomes water (which may be excreted as sweat, urine, and other bodily fluids) and a whopping 84% becomes carbon dioxide. That’s right: We exhale our fat, and it disappears into thin air.

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Are men idiots?

To test the male idiot theory—the hypothesis that “men are idiots and idiots do stupid things”—this study analyzed nominees for the Darwin Awards. Named after the father of evolution, these awards “commemorate those who improve our gene pool by removing themselves from it.” Researchers found that over the last 20 years, nearly 90% of the winners possessed a Y chromosome (rest their souls). They include a guy who shot himself in the head with a “spy pen” weapon to show a friend it was real; and a man who tethered a shopping cart to the last car of a train and tried to hitch a ride inside it. Ouch. But why men do such ridiculously risky things continues to baffle the researchers: "[I]t is puzzling that males are willing to take such unnecessary risks—simply as a rite of passage, in pursuit of male social esteem, or solely in exchange for 'bragging rights,'" they write.

RELATED: 5 Reasons Women Live Longer Than Men

Why are magazines in waiting rooms so old?

Dr. Bruce Arroll in New Zealand decided to investigate this burning question after hearing patients complain again and again about the reading material in his waiting room. For one month, he and his colleagues kept track of 87 magazines at his practice and discovered that nearly half of them disappeared—at a rate of 1.32 magazines per day. As suspected, the most current publications were more popular; but content mattered too. Gossipy magazines (defined as having more than five photos of celebs on the cover) were 14 times more likely to go missing. In fact, not one of the 19 non-gossipy publications (such as Time and The Economist) disappeared, while 26 of the 27 gossipy rags landed in the pockets and purses of sticky-fingered patients.

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