The Checkup: Why Sleeping In on Weekends Can Make You Fat

• If there’s one thing everyone knows about sleep, it’s the concept of sleep debt, the idea that as you scrimp on hours spent in the sack your body accrues all that lost sleeping time, like a silent tally, and eventually makes you pay for it. To help pay back this sleep debt, many of us log extra hours of sleep on the weekends, sleeping in until 10, 11, or sometimes even noon or later (aaahh, the good days of college). A new study shows that this kind of sleeping pattern—where you wake up to an alarm, exhausted, during the week and sleep in on weekends—might actually be doing more harm than good. It’s been dubbed “social jet lag,” because, as TIME puts it, “your body’s basically shuttling back and forth between time zones each week while you’re becoming increasingly sleep-deprived.” Researchers found that those with different weekday and weekend sleeping habits were three times more likely to be overweight than those who woke up at the same time each day. Even scarier, the greater the difference between the rise-and-shine times, the fatter people were. While the research doesn’t prove a causal link between the two, it shows a definite association, and one worth exploring further. Your best bet? Get your 7 to 9 hours of sleep at the same time every night, abolish the alarm, and wake up feeling refreshed.

• Should doctors chart your BMI at checkups, in the same way they do your height, weight and blood pressure? New recommendations for tackling obesity encourage MDs to treat BMI as one of these critical vital signs, reports the Washington Post.

• Only 37.1 percent of young women and 15.6 percent of men in the 18-to-29 age range report using sunscreen. It’s no wonder half of young adults say they got sunburnt in the past year. What people probably don’t realize: “Each time a person burns, his or her risk of skin cancer goes up,” reports TIME.