Newsletter #75: Why Physical Activity Improves Appetite Regulation 💪🏽
Hello Friends!
Welcome to the latest edition of the humanOS newsletter! Here is where we share our work, plus the various studies and media that caught our attention this week. 🤓
This Week’s Research Highlights
⚕ Obesity dramatically raises the risk of developing type 2 diabetes - far exceeding the impact of genes or lifestyle factors.
Researchers applied statistical modeling to a case-cohort sample of 9556 men and women from the Danish prospective Diet, Cancer and Health cohort. The researchers analyzed the impact of body mass index, lifestyle (measured by the variables of smoking, alcohol habits, physical activity, and diet), and genetic risk (assessed by a genetic risk score comprising 193 variants associated with diabetes) on the likelihood of developing type 2 diabetes over ~15 years of followup. Obesity was found to increase risk of type 2 diabetes by 5.8-fold, compared to those with normal weight. Independent effects of high genetic risk and unfavorable lifestyle factors were comparatively modest, conferring 2-fold increased risk and 20% increased risk respectively.
🚘 A relatively mild degree of sleep deprivation can result in poor driving performance on short trips.
Researchers enlisted subjects in simulated driving tasks, and divided them into groups with different levels of sleep deprivation: one with no sleep loss, one with two-hour sleep deprivation, and a third group with four hours of sleep deprivation. Each group drove in the simulator for 45 minutes in the morning and the evening. Results revealed that just two hours of sleep deprivation produced noticeable impairments in driving performance (increased lane deviations). Effects were most pronounced in the morning.
😴 The prevalence of short sleep duration has risen over the past decade.
Researchers analyzed data from the U.S. National Health Interview Survey to determine the prevalence and trends of short sleep duration by demographic and employment characteristics of working adults. The researchers found that the prevalence of short sleep duration had increased significantly, from 30.9% in 2010 to 35.6%in 2018. The highest levels of short sleep duration in 2018 were found for (unsurprisingly): protective service and military (50%), health care support occupations (45%), transport and material moving (41%), and production occupation categories (41%).
👩🎓 Sleep quality, duration, and consistency are associated with significantly better academic performance in college students.
Researchers had 100 students enrolled in an MIT engineering class wear Fitbits for an entire semester. Analysis of the sleep data revealed a nearly-straight line relationship between the amount of sleep that a student got on a regular basis and their academic performance. Effects were substantial - overall course grades for students averaging six and a half hours of sleep were down 50% from students who averaged just one hour more sleep. Consistency also mattered - students who experienced 30 minutes more night-to-night variation in their sleep time had grades that were 45% lower than those who had less variation.
New humanOS Content
- New Recipe Pack: Our Primary Paleo recipe pack is now available for all humanOS Pro users!
- New Functionality: Fitbit now automatically fetches your data to populate your dashboard without having to manually press the sync button (it works that way for Garmin too!). Important quality of life improvement 🙌🏻
- Course Enhancement: We have added a feature called Talking Points to the third course in the Fasting Program (we have also added it to our Stress & Resilience course exclusive for corporate clients - reach out to us to learn more about that). Talking Points is unlocked once you complete a course (just click on the achievement badge), and offers a useful recap of key takeaways from the lessons. You will probably start seeing these in more and more of the courses in the future, so stay tuned 👀
- humanOS Radio: Carbohydrate Availability, Energy Balance, and Exercise. Podcast with Dr. Javier Gonzalez
In this episode of humanOS Radio, Dan speaks with Javier Gonzalez. Dr. Gonzalez is a professor at the Department for Health at the University of Bath in the UK. He and his colleagues recently published a hypothesis suggesting that carbohydrate availability plays a key role in the regulation of energy balance.
What do I mean by carbohydrate availability? Well, our storage capacity for carbohydrates is relatively minuscule, compared to fat stores. These stored carbs can be depleted much faster, and several studies suggest that alterations in carbohydrate availability may be monitored by the body as a gauge of energy balance. Importantly, physical activity influences carbohydrate availability by expending muscle glycogen. This may be a major reason why exercise has been shown to acutely lower fasting leptin concentrations, and why some people become hungry right after working out.
But high physical activity levels - and accompanying high physical fitness - produces relevant changes in carbohydrate and fat metabolism, which might actually make them better able to rein in their appetite after a bout of exercise or after a larger-than-normal meal. To learn about these changes, and more about his fascinating hypothesis, check out the podcast!
Podcasts We Loved This Week
- Raja Dhir: Gut Health, the Microbiome, and How Fiber Protects Your Heart. Via The Genius Life Podcast.
- Rachel Carmody: You Are What You Cook. Via Science Friday.
- Mark Springer: How Whales Evolved From Land To Water, Gene By Gene. Via Science Friday.
Products We Are Enjoying
If you’re looking for a good way to get substantial amounts of turmeric into your diet without having to take a bunch of pills, this is a solid option. One tiny scoop of this powder blend contains 1.5 grams of turmeric (plus black pepper to boost absorption), plus a mix of herbs and adaptogens. I like to add it to carrot and pumpkin smoothies (perfect for autumn), or you can just blend it up with some hot cashew milk to make a golden milk latte. Smells really good too.
humanOS Catalog Feature of the Week
Want to watch this course with us this week? First lesson is just over 2 and a half minutes long. Not yet a Pro user of humanOS? No sweat, this initial module is available for everyone, so give it a shot.