Newsletter #014: Impact of Sleep on young adults and appetite control 💤
Happy weekend friends, and welcome to a brand new HumanOS newsletter! Here we share our own work, as well as studies and media that grabbed our attention.
This week on humanOS Radio, Dan talked with Keith Baar about how the quantity and quality of our muscle tissue influence our long-term health and longevity. There is a ton of interesting and useful information in this interview. Keith talks about how different types of exercise target different tissues, how to eat around training, why we need to strengthen not just muscles but also connective tissue, how ketogenic diets may affect mitochondrial networks, and how lack of non-exercise physical activity might impair response to exercise training. I highly recommend you check this out!
Finally, our friends at Biohacker Summit have joined forces with our friends at SPARK and are putting on what is set to be a great event from 14th to 16th October in Toronto. The talks will cover an array of juicy topics, including ketogenic diets, medicinal uses of psychedelics, meditation, and neurofeedback, and Greg will be speaking about how diet affects circadian rhythms. Check it out here, and if you’d like to come along then you can use the code vip15 to get 15% off attendance!
This Week’s Research Highlights
😴 Young adults are more vulnerable to chronic sleep deficiency and recurrent circadian disruption than older adults.
Researchers compared data from younger and older adults who underwent three weeks of chronic sleep restriction (equivalent to about five and a half hours of sleep per 24 hours period). They found that both groups reported similar levels of subejctive sleepiness. However, objective measurements revealed that younger adults had more attentional failures than older adults. This may be particularly relevant to prevention of sleep-related accidents, such as motor vehicle collisions.
💤 Different levels of urbanization may affect sleep through altered light exposure patterns.
Researchers compared sleep patterns in settlements in Brazil with different levels of industrialization. They found that communities who either did not use electricity or had only recently become exposed to it slept earlier and longer on average than counterparts in more urbanized societies. The introduction of electricity transformed daily rhythms that had been entrenched for thousands of years, and it may have had an impact on our health as well.
🥱 Poor sleep quality, independent of sleep duration, affects appetite control.
Researchers recruited 12 healthy young men and had them spend the night at the sleep lab on two separate occasions. In one session, they were permitted to get eight hours of uninterrupted sleep, and in the other session they also slept for eight hours but their sleep was fragmented through repeated alarms. Polysomnography showed that they achieved the same total sleep time in the fragmented condition, but their REM sleep was significantly truncated. The following day, blood samples showed reduced circulating concentrations of the satiety-enhancing gut hormone GLP-1, compared to when they got uninterrupted sleep, and they reported increased desire to eat.
Podcasts We Loved This Week
- Carl Juneau: Does Muscle Damage Actually Cause Hypertrophy? Via Sigma Nutrition Radio with Danny Lennon.
- Siddhartha Mukherjee: The Moral Complexity of Genetics. Via Waking Up with Sam Harris.
Products We Are Enjoying
Wild Blueberry Juice Concentrate.
Eric says: Just one tablespoon is equivalent to one cup of wild blueberry fruit juice. We like to mix a 1-to-1 ratio of this product with agave as a topping for snow cones - perfect on a hot day! Dan likes to make a refreshing concoction of blueberry juice concentrate, acacia fiber, glycine, and water. Not only are they delicious, but blueberries are a rich source of polyphenols, particularly anthocyanins. If you would like to learn more about blueberries and the health benefits associated with them, you can read about them in this blog.
New humanOS Content and Features
- Blog and podcast: Muscle and Health Podcast with Keith Baar.
New Feature: You will now be able to access Achievements from your humanOS.me dashboard! Achievements enable you to see how many lessons and courses you have consumed. As you go through the content, progress bars will gradually fill up, and you will receive badges when you complete courses. Here is a quick but handy tutorial to show how it works:
Eating crickets modulates the gut microbiome and reduces systemic inflammation.
Consuming 25 grams/day of whole cricket powder for six weeks resulted in increased growth of the probiotic bacterium Bifidobacterium animalis. Subjects eating the cricket powder also showed reduced plasma TNF-α, a protein that is involved in systemic inflammation.
Higher fasting plasma glucose is associated with accelerated brain aging - even in those who do not have diabetes.
A 1 mmol/l increase in plasma glucose (above 5 mmol/l in non-diabetic and above 6.1 mmol/l in type 2 diabetes) resulted in a 10–13% increase in annual cortical thinning.
People lose less weight if their gut microbiome is better able to metabolize carbs.
Researchers examined the gut microbiome of participants in a lifestyle intervention program. In those who were less successful at losing weight, they found bacterial genes encoding for enzymes associated with breaking down and harvesting energy from carbs.
Even relatively mild dehydration may impair cognitive performance.
A new systematic review and meta-analysis of 33 studies found that dehydration impairs performance on tasks involving attention, executive function, and motor coordination. Effects became evident when water deficits exceed just 2% body mass loss.
humanOS Catalog Feature of the Week
Sleep and Weight Control
This week, we’d like to highlight one of the courses from the Ideal Weight Program, developed by Stephan Guyenet. Much of the Ideal Weight Program is centered around nutrition, as you would expect, but research has shown that multiple aspects of our lifestyle play an important role in body weight. Sleep is one of the most important, and perhaps most underappreciated.
In this course, Stephan reviews the basics of sleep and circadian rhythms, then zooms in on how insufficient or misaligned sleep specifically influences body fatness. He looks at a few key studies that have examined the impact of altered sleep on food intake, which largely mirror the findings that we described above. But it actually gets even worse - sleep loss can also adversely affect nutrient partitioning, making it harder for you to hold onto muscle! Fortunately, this is for the most part a solvable problem. Stephan covers realistic ways for you to obtain restorative sleep, and hopefully achieve your body composition (and health) goals.
Wishing you the best,
