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睡眠也许是健康中被忽视的继母 Sleep is perhaps the neglected stepsister in the health
今天的谈话。 conversation of today.
我们经常听说锻炼和身体活动。 Often, we hear about exercise and being physically active.
我们听说了健康饮食和良好饮食。 And we hear about healthy eating and having a good diet.
但是很少有人真正听说睡眠的重要性 But very few of us actually hear about the importance of sleep
总的来说是为了我们的健康。 in general for our health.
结果发现睡眠不足 And it turns out that insufficient sleep
会影响你管理身体的能力 will compromise your ability to manage your body
节食减肥。 weight with dieting.
例如，一项研究发现 One study, for example, found that in individuals
如果睡眠不足 who weren't getting sufficient sleep, if they were getting
每晚睡眠不足6小时， less than six hours of sleep a night,
他们减掉体重的70% 70% of all of the weight that they lost
来自瘦肌肉而不是脂肪。 came from lean muscle mass and not fat.
为什么你的身体会这样？ Now, why would your body do this?
脂肪是一种富含能量的物质。 Fat is a highly energy-rich substance.
当你睡眠不足时，你的身体 When you are under-slept, your body
会故意变得吝啬放弃它的脂肪。 will deliberately become stingy in giving up its fat.
它会开始新陈代谢，比如肌肉， It will start to metabolize things such as muscle,
这是蛋白质。 which is protein.
换句话说，当你睡眠不足时， In other words, when you're not getting sufficient sleep,
如果你想节食的话 and you're trying to diet, then you actually
失去你想要保留的东西，那就是肌肉。 lose what you want to keep, which is muscle.
你还坚持你想失去的东西，那就是脂肪。 And you hold on to what you want to lose, which is fat.
所以你可能把所有这些努力 So it may be that you're putting all of this diligent hard work
节食。 into dieting.
你在控制你的欲望。 You're managing your cravings.
你在战斗。 You're fighting that battle.
但如果你睡眠不足， But if you're not getting sufficient sleep,
那么你可能只是在解开所有那些辛苦的工作 then you may be just unraveling all of that hard work
每天晚上都在努力工作 every night and compromising all of that hard work
你白天做的事。 that you're doing during the day.
当我们睡眠不足时， When we're not getting sufficient sleep,
不仅仅是我们的食欲激素 it's not only our appetite hormones
它们变得失调，但我们也发现了变化 that become dysregulated, but we've also discovered changes
在大脑内部。 within the brain itself.
几年前，我们做了一项研究。 Several years ago, we did a study.
我们选取了健康人。 And we took healthy individuals.
我们让他们睡了一整晚， And we gave them a full night of sleep,
然后我们把他们带回来。 and then we brought them back.
我们剥夺了他们一夜的睡眠。 And we sleep deprived them for a night.
第二天，我们把它们放进核磁共振扫描仪里。 And the next day, we put them inside an MRI scanner.
我们向他们展示了各种不同的食物 And we showed them a whole range of different foods from things
对那些 that were very healthy to things that
非常愉快，令人向往，但非常不健康。 were devilishly pleasurable and desirable but very unhealthy.
我们测量了大脑的反应 And we measured the brain's response
当它看到这些图像的时候。 as it was viewing these images.
我们发现当这些人 And what we found is that when those individuals were
睡眠不足，当他们被剥夺睡眠时， under-slept, when they were sleep-deprived,
大脑的反应方式不同 the brain was responding in a different way
对于那些非常渴望，非常快乐的人， to those highly desirable, highly pleasurable,
上瘾的食物。 addictive foods.
具体来说，我们发现 Specifically, what we found is that there
是大脑中一个叫做杏仁核的深层情感中心。 is a deep emotional center in the brain called the amygdala.
杏仁核做的一件事 And one of the things that the amygdala does
就是调节我们的积极和消极情绪。 is regulate our positive and negative emotions.
我们发现当这些人 And we found that when those individuals hadn't been getting
睡眠，杏仁核，这个享乐中心， sleep, the amygdala, this hedonic center,
作为回应，他点亮了更明亮的灯 was lighting up far more brightly in response
给那些非常愉悦，非常不健康的食物。 to those very pleasurable, very unhealthy foods.
我们还发现大脑的另一部分 And we also found that another part of the brain
叫做前额叶皮层 called the prefrontal cortex that sits directly
在你的眼睛上方，这有助于调节 above your eyes, which helps try to regulate
当你走过这些欲望的冲动 these impulses, these desires of when you walk past
这些冲动，这些欲望 these impulses, these desires of when you walk past
在超市里，像冰淇淋冰箱， in the supermarket, the sort of the ice cream refrigerator,
你会想，哦，我真的想要一品脱这个 and you think, oh, I would really like a pint of this
再来一品脱。 and a pint of that.
但你认为，不，我是想表现好。 But you think, no, I'm trying to be good.
我正努力保持这种饮食习惯。 I'm trying to stay on this diet.
我要走过它。 I'm going to walk past it.
这是你的前额叶皮层告诉你的逻辑 That's your prefrontal cortex telling you the logic
控制着深层快乐的大脑中枢。 and controlling that deep hedonic brain center.
但是大脑的这一部分由于睡眠不足而受损。 But that part of the brain was impaired by a lack of sleep.
所以我们失去了大脑中的冲动控制部位。 So we lost the impulse control site within the brain.
相反，我们得到了这个提升 And instead, we got this ramping up
大脑中快乐的部位。 of the hedonic site within the brain.
所以现在我们让位于我们愉悦的欲望。 So now we're giving way to our pleasurable desires.
这也是我们开始的另一个原因 And that's another reason why we start
以更不健康、更冲动的方式进食 to eat in more unhealthy, more impulsive ways
当我们睡眠不足的时候。 when we're not getting sufficient sleep.
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现在我们来谈谈睡眠和睡眠的关系 Now let's speak about the relationship between sleep
你的体重和食欲的控制 and your body weight and the control of your appetite
还有你的饥饿。 and your hunger.
为此，我想介绍 And to do that, I want to introduce
两种不同的食欲调节激素。 two different appetite-regulating hormones.
它们被称为瘦素和生长素。 They are called leptin and ghrelin.
瘦素是对食物表示满意的荷尔蒙。 Leptin is the hormone that signals satisfaction with food.
瘦素告诉你的大脑和身体 And leptin tells your brain and your body
你不再饿了。 you're no longer hungry.
你可以不吃了。 You can stop eating.
它给你一种 It gives you a feeling that you've
我对你的食物很满意，而且你吃饱了。 been satisfied by your food and that you're full.
Ghrelin的作用正好相反。 Ghrelin does the opposite.
Ghrelin是我们认为的饥饿激素。 Ghrelin is what we think of as the hormone of hunger.
当我们有高浓度的ghrelin时， When we have high concentrations of ghrelin,
我们通常想要吃得更多。 we typically want to eat more.
即使你吃了一顿饱饭，如果ghrelin水平仍然很高， And even if you eat a full meal, if ghrelin levels remain high,
你不会对那食物感到满意的。 you won't feel satisfied with that food.
你还是想多吃点。 You'll still want to eat more.
更有可能的是，你会吃得更多。 And more than likely, you will eat more.
你会吃得太多的。 You'll eat to excess.
研究告诉我们睡眠不足 And what studies have taught us is that a lack of sleep
可以改变这些食欲调节激素的平衡 can change the balance of these appetite-regulating hormones
以有害的方式推动我们 in deleterious ways that can push us
走向体重增加甚至肥胖的道路。 towards a path of weight gain or even obesity.
一系列研究选取了其他健康的成年人 A collection of studies have taken otherwise healthy adults
正常体重，然后他们 of normal weight, and then they've
把它们放在两个不同的条件下。 put them under two different conditions.
要么他们给了他们很多 Either they've been giving them plentiful
睡几个晚上，或者他们限制他们的睡眠 sleep for several nights, or they restrict their sleep
一个晚上可能只有四五个小时。 to maybe just four or five hours a night for several nights.
在实验阶段结束时， And then at the end of that experimental phase,
他们将实际测量瘦素和ghrelin的水平 they will actually measure the levels of leptin and ghrelin
它们在血液中循环。 that are circulating in their bloodstream.
他们发现的基本上是双重打击 And what they discovered was essentially a double whammy
效果。 effect.
他们发现瘦素水平 They found that levels of leptin, the hormone that
通常说“别担心，你不饿， normally says "Don't worry, you're not hungry,
你对你的食物很满意 you're satisfied with your food,"
在那些睡眠受到限制的人身上， in those people who had been sleep-restricted,
他们的瘦素水平下降了。 their levels of leptin had gone down.
如果这还不够糟糕，他们还发现了什么 If that wasn't bad enough, what they also found
是饥饿激素ghrelin的水平， was that levels of ghrelin, the hunger hormone,
实际上是相反的方向。 had actually gone in the opposite direction.
它们实际上已经增加了。 They had actually increased.
总的来说，这些人报告的饥饿程度 Overall, the hunger levels that those individuals reported
也更高。 was higher as well.
他们还有一件事 There was another thing that they
在这些研究中发现。 identified in those studies.
那些睡眠不足的人，尽管吃了 Those under-slept people, despite eating
他们似乎更喜欢每一种食物 more of every food group, they seemed
吃更多的重击， to eat much more of the heavy-hitting,
沉闷的碳水化合物和单糖。 stodgy carbohydrates and simple sugars.
换句话说，当你睡眠不足时， So in other words, when you are under-slept,
你会开始伸手去拿比萨饼之类的东西 you're going to start reaching for things such as pizza
还有意大利面、面包、冰淇淋和甜点 and pasta and bread and ice creams and desserts
而不是一把绿叶蔬菜或一些健康的鱼 rather than a handful of leafy greens or some healthy fish
因此。 as a consequence.
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不仅仅是食欲调节激素，甚至 Beyond simply appetite regulating hormones or even
生殖激素，还有另一组激素变化 reproductive hormones, there's another set of hormonal changes
由于睡眠不足而导致的偏斜。 that are skewed by way of insufficient sleep.
这些是代谢激素，尤其是 And these are the metabolic hormones, particularly
有助于控制血糖的东西， things that help control our blood sugar,
换句话说，我们的血糖水平。 in other words, our blood glucose levels.
现在，血糖及其调节的方式 Now, the way in which blood glucose and its regulation
典型的效果是当我们吃饭的时候， typically works is that when we eat a meal,
我们的血糖水平会开始上升。 our blood sugar levels will start to rise.
但实际上对身体很危险 But it's actually quite dangerous for the body
高血糖，高血糖， to have high levels of blood sugar, high levels of glucose,
很长一段时间。 for long periods of time.
事实上，如果我们有长期的高水平 And in fact, if we have chronically high levels
血糖，这会让我们走上2型糖尿病的道路 of blood sugar, that can set us on a path towards type 2
糖尿病。 diabetes.
所以当我们 So what we always want to do when
我们看到血糖水平上升 we see a spike in our blood sugar levels
有一个很好的身体系统 is have a body system that is very well
擅长迅速降低血糖水平。 adept at very quickly bringing back down those glucose levels.
身体是怎么做到的？ How does the body do this?
其中一个机制是当身体发出信号 Well, one of the mechanisms is that when the body signals
或者收到高血糖的信息， or receives the message of high blood sugar,
它释放一种叫做胰岛素的激素。 it releases a hormone called insulin.
然后胰岛素开始在全身循环。 And that insulin then starts to circulate all over the body.
身体需要释放适量的胰岛素 The body needs to release the appropriate amount of insulin
对体内的细胞说是时候分类了 to say to the cells in the body it's time to sort
几乎是隐喻性的把吸管拔出来然后开始 of almost metaphorically pull your straws out and start
从血液中吸入葡萄糖 sucking in that glucose from the bloodstream
这样我们就不会有这样的血糖 so that we don't get this monsoon of blood sugar
在我们的血液里旋转。 swilling around within our blood.
第二件事是， The second thing is that, however,
体内的细胞需要倾听 those cells in the body need to be listening
胰岛素的信号。 for the signal of insulin.
即使身体释放了适量 Even if the body is releasing the appropriate amount
如果这些细胞不听话，胰岛素就会进入血液 of insulin into the bloodstream, if those cells aren't listening
胰岛素，那么这些细胞就不会开放， to the insulin, then those cells won't open up,
降低血糖。 lowering that blood sugar.
我们发现睡眠不足 And what we found is that a lack of sleep
破坏了代谢血糖方程的两边。 disrupts both sides of that metabolic blood sugar equation.
这是一组因果关系的研究 And this is a causal set of studies where you take people
没有糖尿病迹象的人。 who have no signs of diabetes.
你限制他们只睡四五个小时 And you limit them to maybe just four or five hours of sleep
四五个晚上，然后你 a night for four or five nights, and then you
给他们一杯非常含糖的葡萄糖饮料 give them a very sugary glucose drink that
会使他们的血糖升高到标准水平。 will raise their blood sugar a standard amount.
首先，他们发现当这些人 And firstly, what they found is that when those individuals had
睡眠不足， not been getting sufficient sleep,
身体没有释放足够的胰岛素。 the body wasn't releasing enough insulin.
如果这还不够糟糕的话，体内的细胞 If that wasn't bad enough, the cells in the body
也变得无知，或者 had also become ignorant, or they'd
别再听胰岛素分泌的信号了 stop listening to the signal of what little insulin had
实际上已经被释放了。 actually been released.
所以在血糖调节方程的两端， So on both ends of the blood sugar regulation equation,
睡眠不足削弱了这种能力 a lack of sleep was impairing that capacity
调节血糖。 to regulate blood sugar.
结果，它减少了调节，吸收， And as a result, it reduced the regulation, the absorption,
在那些健康的人中，葡萄糖的含量降低了40%左右。 of glucose by about 40% in those healthy individuals.
如果他们的医生检查过 If those individuals had been checked by their doctor
在那一刻，他们的医生会 at that moment, their doctor would
对这些人进行了分类 have classified those individuals
处于糖尿病前期。 as being in a prediabetic state.
所以，换言之，短睡眠时间只有一周 So, in other words, short sleep duration for just one week
会让你的医生，你的家庭医生，去拿处方 will have your doctor, your GP, reaching for that prescription
因为他们会把你登记为 because they would register you as being
就在患2型糖尿病的尖端 right on the cusp of suffering from type 2 diabetes, which is
极度严重的紊乱。 a desperately serious disorder.
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除了我们食欲荷尔蒙的变化 Beyond changes in our appetite hormones
甚至改变我们大脑的运作方式， or even changes in how our brain operates,
我们也开始明白睡眠不足 we're also starting to understand that a lack of sleep
可以改变肠道微生物组。 can change the gut microbiome.
肠道微生物群是这片不可思议的森林 The gut microbiome is this incredible forest
动植物细菌 of flora and fauna bacteria as it
有助于调节健康的体质吗 were that helps regulate a healthy constitution
在我们的肠道内，在我们的肠道内。 within our intestinal tract, within our gut.
我们发现人们 And what we've been finding is that in people
报告睡眠不足， who report getting insufficient sleep,
肠道微生物群的平衡发生了变化。 there is a change in the balance of the gut microbiome.
它更倾向于发酵的种类。 It shifts over more towards a bias of fermented species.
它从更多以细菌为基础的物种中转移出来。 And it shifts away from more of the bacterial-based species.
我们认为这不是最优的原因 And the reason that we think that that's not optimal
如果我们看一个人 is that if we look at individuals
有健康状况的人，比如糖尿病 who have health conditions, things such as diabetes
或者超重的人，他们确实 or people who are overweight, they have exactly
同样不正常的肠道轮廓 that same abnormal profile of a gut
微生物组与我们在没有 microbiome to that which we see in individuals who aren't
充足的睡眠。 getting sufficient sleep.
我们认为微生物群 One of the reasons that we think that the microbiome undergoes
当我们不睡觉时有害的变化 deleterious changes when we're not sleeping
是由一种叫做皮质醇的激素引起的。 is due to a hormone called cortisol.
每个人都需要皮质醇。 Everyone needs cortisol.
这是健康生物学的一部分。 It's part of a healthy biology.
但如果皮质醇过多， But if we have too much cortisol,
它开始像一种慢性应激相关激素。 it starts to act like a chronic stress-related hormone.
这会产生多方面的后果 And that has manifold consequences
这些都已经被科学证明了，比如改变 that have been well proven by science such as changes
你的心血管疾病风险，糖尿病的变化， in your cardiovascular disease risk, changes in diabetes,
与抑郁症和精神疾病的关系。 relationships with depression and mental illness.
但是皮质醇的另一个作用 But one of the other things that cortisol will do
在这种有害的，不平衡的环境中，微生物群是否发生了变化 is shift the microbiome in this deleterious, imbalanced
方向。 direction.
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这就是睡眠对食物相关行为的影响， So that's the impact of sleep on food-related behaviors,
食物的选择和种类的数量。 the selection of your foods and the amount of the type of food.
但现在让我们改变这种联系。 But now let's change that association.
我们倒过来。 Let's reverse it.
你能把你白天吃的食物 Can the food that you're eating during the day
或者在晚上影响数量 or in the evening impact the quantity
你晚上的睡眠质量如何？ and the quality of your sleep at night?
所以我们首先发现的是高糖饮食 So first what we found is that diets that are high in sugar
纤维含量低通常对你晚上的睡眠不利。 and low in fiber are typically worse for your sleep at night.
因此，你的深度睡眠会减少。 And as a result, you will have less deep sleep.
而且你更有可能在晚上醒来。 And it's more likely that you will wake up during the night.
其中一个原因是糖，尤其是 One of the reasons for this is that sugar, particularly
如果你一整天都在吃，尤其是 if you're eating it throughout the day and especially
晚上，会增加你的新陈代谢率 in the evening, will increase your metabolic rate
尤其是你的体温。 and particularly your temperature.
不仅仅是不同种类的食物 It's not just the different types of food
你吃的东西会影响你晚上的睡眠。 that you're eating that can impact your sleep at night.
这也是你进食的时间。 It's also the timing of your food intake.
一般规律是不要饿着肚子睡觉。 The general rule is don't go to bed desperately hungry.
不要睡得太饱，对大多数人来说 And don't go to bed too full and for most people, trying
在睡前两三个小时停止进食。 to stop eating, say, two or three hours before bed.
如果你需要一点零食 If you need a little bit of a snack
睡觉前只是为了减轻饥饿感，没关系。 before bed just to take the edge off your hunger, that's OK.
但要确保这不是那种 But make sure it's not a snack that
里面有高浓度的糖。 has high concentrations of sugar in it.
给你的身体一个机会——给它 And give your body the chance-- give it
一个小时或几个小时来消化食物。 an hour or a couple of hours to try to digest that food.
因此，你会给自己 And therefore, you'll give yourself
有机会在晚上睡个好觉。 the chance for better, restful sleep at night.
所以这是一种双向关系 So it's a bidirectional relationship
当涉及到睡眠、食物和饮食时。 when it comes to sleep, food, and diet.