Casey Means, MD is a Stanford-trained physician and co-founder of Levels, a health technology company with the mission of reversing the world’s metabolic health crisis. Her book on metabolic health, Good Energy, comes out in May 2024 with Penguin Random House (pre-order here!). She received her BA with honors and MD from Stanford, was President of her Stanford class, and has served on Stanford faculty. She trained in Head & Neck Surgery before leaving traditional medicine to devote her life to tackling the root cause of why Americans are sick. She has been featured in The New York Times, The New Yorker, The Wall Street Journal, Forbes, Women’s Health, and more.
What’s your overall approach to sleep as a pillar of your health? How do you think about sleep?
Especially after diving even deeper into the research on sleep for my book,Good Energy, I can tell you sleep is one of the single most important investments we can make for our mental and physical health. The research is clear and overwhelming. And right now, we are not doing a good job at it. Compared to one hundred years ago, we are sleeping on average 25 percent less. That’s 25 percent less time for our bodies to do its critical processes of biological repair, recovery, and memory consolidation. Every time we skimp on the quantity, quality, or consistency of sleep, we inch toward the grave—and toward metabolic symptoms and diseases— by generating oxidative stress, mitochondrial dysfunction, chronic inflammation, plus a big helping of microbiome dysfunction. Lack of quality sleep is a profound “danger” signal to the body, throwing off proper metabolism and promoting fat storage. I think about sleep in three ways:
- Sleep quantity: Getting 7-8 hours a night of good quality sleep.
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Study highlight: One study found healthy, normal-weight individuals who slept fewer than 6.5 hours per night had to produce 50 percent more insulin than normal sleepers to achieve similar glucose results—placing the short sleepers at significant risk of developing insulin resistance in the long term. Remember, prediabetes and type 2 diabetes are insulin resistance—a root of nearly every other chronic symptom and disease.
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- Sleep quality: Getting minimally interrupted sleep.
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Study highlight: One study followed over two thousand adult men for eight years and found that subjects who reported difficulty maintaining sleep had a two- fold to threefold higher risk of developing type 2 diabetes. And in the short term, studies showed a link between sleep quality and the immediate ability to manage blood sugar efficiently the next day
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- Sleep consistency: This is the hardest one for me, but keeping a consistent bedtime and wake time matters profoundly for our metabolic health. More on this in one of the later questions about “social jet lag”
Poor quality and quantity of sleep generate a wide array of downstream effects that damage the mitochondria. Lack of quality sleep leads to hormonal imbalances, including altered cortisol, insulin, growth hormone, and melatonin levels, all of which interact with the mitochondria. Additionally, sleep deprivation disrupts the expression of genes involved in the production of new mitochondria and replication of mitochondria. Sleep deprivation generates increased damaging free radicals, both by activating cellular machinery that makes free radicals and by inhibiting the production of antioxidants.
I mention Professor Matthew Walker in my book, Good Energy, because he notes that the Guinness Book of World Records still recognizes “Most Motorcycles Driven over the Body While Lying on a Bed of Nails” but has stopped recognizing attempts to break the sleep deprivation record because these attempts are just too dangerous. Lack of sleep is dangerous. Every person should prioritize the quantity, quality, and consistency of sleep like their life depends on it!
What tips do you have on going to sleep earlier, as well as getting up
earlier?
Historically, my sleep issue is that I am a notorious night owl and go to bed at late times and my bedtime bounces around night to night. This is NOT good for your health, particularly because we tend to get more deep sleep earlier in the night. The research shows that “sleep consistency” — meaning regular sleep and wake times — is really important for metabolic health, above and beyond sleep quantity and quality (which we all know are important!).
I have tried every sleep hack in the book to get to bed at a more consistent time, including having a sleep coach for a while (through the app Crescent Health, which was great!), texting my sleep data to my best friend every day (and having to literally Venmo her money if I don’t go to bed at the goal time I’d set), and planning early workouts so I’d be forced to get up early (and hopefully then go to bed earlier). I believe in accountability and these strategies were helpful, but the honest truth is that the thing that has transformed my sleep more than anything is living with my partner who likes to go to bed at a more reasonable time than me!
Simply living with someone I deeply respect and love who has a healthier habit than me (consistent sleep!) rubbed off on me almost instantly. This isn’t to say that you should pick a partner just based on their bedtimes! What it did solidify to me, though, and is the takeaway, is that having support for health goals from the people closest in your life can be transformational for success, and we should aim to surround ourselves with healthy people if being healthy is our goal!
Research has shown that who you surround yourself with directly impacts your health. For instance, if one spouse becomes obese, it almost doubles the risk of their partner becoming obese. What a mother eats before conception, during pregnancy, and even after a child is born is an extremely strong factor in the child’s health outcomes. What’s more, social support and a sense of community are known to help a person do better in the face of many different diagnoses, from cancer.) to heart disease. Fast food consumption “