This is Scientific American — 60-Second Science. I'm Karen Hopkin.
Few things are more satisfying than sleeping late on weekends. But though the extra z's may improve your mood, they do not appear to improve your health. Because a new study shows that so-called "recovery sleep" cannot reset the body's metabolic clock...and may actually lead to some serious health issues.
"Sleep loss can impact a range of physiological systems. It can increase our risk for cardiovascular disease, it can cause weight gain, it can decrease insulin sensitivity, so it can increase our risk of diabetes...."
Christopher Depner, an assistant professor in the department of integrative physiology at the University of Colorado, Boulder.
"And this can happen, depending on what you're looking at, this can happen as quick as just one or two nights of not getting enough sleep."
A lot of us shut off the alarm on Saturday and Sunday. But we go right back to burning the candle at both ends once the workweek begins.
"So we were really interested in how the sort of cycle of between insufficient sleep, weekend recovery sleep, insufficient sleep, can impact your risk of obesity and metabolic disease."
Depner and his colleagues invited volunteers to a nine-day snooze-a-thon. One group was allowed to get a full night's sleep. The next was kept to just five hours each night. And the third group went back and forth, restricted to five hours of shut-eye during the workweek, allowed as much sleep as they wanted over the weekend, and then back to five hours for the last couple days.
"Well, the key findings from this study show that when we maintain insufficient short sleep schedules during a typical work or school week, we find that this leads people to eat more than they need and this leads to weight gain. And when they are eating more, they actually eat more predominantly after-dinner snacks. And this altogether also leads to reduce the ability for us to regulate our blood sugar levels."
Ken Wright, professor of integrative physiology at U.C. Boulder. He's the senior author of the study, which appears in the journal Current Biology.
So it seems a loss of sleep leads to a spike in snacking. But even more surprising, sleeping in on the weekend doesn't help—and even makes things worse.
"We found that after the weekend, when they went back to getting insufficient sleep during the work or school week, we found that their liver and their muscle insulin sensitivity or blood sugar regulation was reduced. And this is not something we had found in people who maintained chronic insufficient sleep schedules. So it's possible that, yes, this is a worsening of the body's ability to regulate blood sugar for those specific tissues after the weekend."
So make a date with a pillow. And trade the sweets for sweet dreams.
Thanks for listening for Scientific American — 60-Second Science. I'm Karen Hopkin.
没有什么比周末睡懒觉更令人满足了 。但是，尽管额外的睡眠或许会改善你的情绪，但其似乎不会改善你的健康 。因为一项新研究表明，所谓的“补觉”不能重置身体的新陈代谢时钟，而且还可能导致一些严重的健康问题 。
我们很多人会在周六日关掉闹钟 。但工作日一开始，我们就会立刻回到拼命工作的状态 。
德普纳及其同事邀请志愿者参加为期9天的睡眠马拉松活动 。他们允许其中一组志愿者睡一整晚 。第二组每晚只能睡5个小时 。第三组则反复循环——工作日睡眠时间限制在5个小时，而周末则可以想睡多久就睡多久，最后几天再回到每晚只睡5小时的状态 。
“这项研究的关键发现表明，当人们在典型工作日或上学日持续睡眠不足时，我们发现这会导致人们吃得比他们需要的多，继而导致体重增加 。”当人们吃得更多时，他们实际上吃的更多是餐后零食 。这也会降低我们调节血糖水平的能力 。
科罗拉多大学博尔得分校的整合心理学教授肯·赖特说到 。他是发表在《当代生物学》期刊上的这篇研究的资深作者 。
因此，睡眠不足似乎会导致零食摄入量激增 。但更令人惊讶的是，周末睡懒觉不仅没有帮助，甚至会使情况变得更糟 。
“我们发现，周末过后，当志愿者回到工作日或上学日睡眠不足的状态时，他们的肝脏和肌肉胰岛素敏感性或血糖调节能力都降低了 。而我们在长期睡眠不足的人身上并没有发现这种情况 。因此，很有可能在周末过后，人体为某些特定组织调节血糖的能力恶化了 。”
所以，还是和枕头约会吧 。每晚把糖果换成甜蜜的梦 。
谢谢大家收听科学美国人——60秒科学 。我是凯伦·霍普金 。
1. depend on 取决(于)；有赖(于)；
The cooking time needed depends on the size of the potato.
2. shut off 关闭；关上；使停止运转；
They pulled over and sh ut off the engine.
3. burn the candle at both ends 一根蜡烛两头烧；起早摸黑地干；过度耗费精力；
You can't burn the candle at both ends.
4. trade sth. for sth. 用…进行交换；互相交换；
They traded land for goods and money.