Wellness, Home & Lifestyle, Science & Tech

Diet and Sleep

Matthew Walker

Lesson time 15:19 min

What you eat affects how well you sleep and vice versa. Learn how sleep influences your eating habits.

Students give MasterClass an average rating of 4.7 out of 5 stars

Topics include: Sleep and Hunger • Blood Sugar Battle • Your Gut Reaction • Eat Right to Sleep Better


[MUSIC PLAYING] - Sleep is perhaps the neglected stepsister in the health conversation of today. Often, we hear about exercise and being physically active. And we hear about healthy eating and having a good diet. But very few of us actually hear about the importance of sleep in general for our health. And it turns out that insufficient sleep will compromise your ability to manage your body weight with dieting. One study, for example, found that in individuals who weren't getting sufficient sleep, if they were getting less than six hours of sleep a night, 70% of all of the weight that they lost came from lean muscle mass and not fat. Now, why would your body do this? Fat is a highly energy-rich substance. When you are under-slept, your body will deliberately become stingy in giving up its fat. It will start to metabolize things such as muscle, which is protein. In other words, when you're not getting sufficient sleep, and you're trying to diet, then you actually lose what you want to keep, which is muscle. And you hold on to what you want to lose, which is fat. So it may be that you're putting all of this diligent hard work into dieting. You're managing your cravings. You're fighting that battle. But if you're not getting sufficient sleep, then you may be just unraveling all of that hard work every night and compromising all of that hard work that you're doing during the day. When we're not getting sufficient sleep, it's not only our appetite hormones that become dysregulated, but we've also discovered changes within the brain itself. Several years ago, we did a study. And we took healthy individuals. And we gave them a full night of sleep, and then we brought them back. And we sleep deprived them for a night. And the next day, we put them inside an MRI scanner. And we showed them a whole range of different foods from things that were very healthy to things that were devilishly pleasurable and desirable but very unhealthy. And we measured the brain's response as it was viewing these images. And what we found is that when those individuals were under-slept, when they were sleep-deprived, the brain was responding in a different way to those highly desirable, highly pleasurable, addictive foods. Specifically, what we found is that there is a deep emotional center in the brain called the amygdala. And one of the things that the amygdala does is regulate our positive and negative emotions. And we found that when those individuals hadn't been getting sleep, the amygdala, this hedonic center, was lighting up far more brightly in response to those very pleasurable, very unhealthy foods. And we also found that another part of the brain called the prefrontal cortex that sits directly above your eyes, which helps try to regulate these impulses, these desires of when you walk past in the supermarket, the sort of the ice cream refrigerator, and you think, oh, I would really like a pint of this and a pint of that. But you think, ...

About the Instructor

As a professor of neuroscience and psychology at UC Berkeley and the director of the Center for Human Sleep Science, Matthew Walker is an expert on sleep. In this class, he will illuminate the science behind sleep and teach you how to increase the quality and quantity of your sleep. Learn how to prevent sleep debt, navigate the effects of alcohol and caffeine, and improve your health. Your best sleep starts tonight.

Featured Masterclass Instructor

Matthew Walker

Neuroscience professor Matthew Walker teaches you the science of sleep and how to optimize it to better your overall health.

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