To a Healthy New Year
Lifestyle Health Wrap #15
I usually don’t rely so heavily on AI to write these, but this week I used Google’s NotebookLM to draft the first three sections and it was very helpful.
I hope you, like me, have been able to get some rest and relaxation and spend time with friends and family during this holiday season. Happy new year and I hope you enjoy this week’s wrap!
As always, please let me know if you notice any mistakes, have feedback, or have any questions.
Sections
DIET | EXERCISE | SLEEP | STRESS | CONNECTION | OTHER
Diet
How much protein can the body use in a single meal for muscle-building? Implications for daily protein distribution | April 1, 2022
https://doi.org/10.1186/s12970-018-0215-1
Review
This paper explores how much protein the body can use to build muscle in a single meal, and how to best distribute protein intake throughout the day. The authors reviewed existing studies to determine the ideal amount of protein to consume per meal to maximize muscle growth.
Here are the key takeaways:
The body can absorb a lot of protein: There's no real limit to how much protein the body can absorb in the gut from a meal. The issue is how much of that protein is used to build muscle, rather than for energy or other things.
The "muscle full" concept: It was previously thought that muscle growth was maximized with about 20-25 grams of high-quality protein in one meal and that anything more would be wasted. This is probably not the case though, particularly if the protein is ingested after resistance training and/or the protein is slow-digesting. While higher protein intake does lead to more amino acid oxidation (meaning some of the protein is used for energy), not all of the extra protein is wasted. Some of it is still used for building tissue.
Digestion speed matters: The speed at which protein is digested affects how much is used for muscle growth. Slower-digesting proteins, especially when eaten with other foods, can be more effective because they release amino acids more slowly. For example, cooked eggs digest more slowly than whey protein.
How much protein is ideal per meal? To maximize muscle growth, the authors suggest aiming for at least 0.4 grams of protein per kilogram of body weight per meal and a minimum of 1.6 grams per kg of body weight per day. For example, a 165-pound person (~75 kg) should aim to consume at least 30 g of protein per meal and 120 g/day. A 187-pound person (~85 kg) should aim to consume about 34 g of protein per meal and 136 g/day.1 Some people may even benefit from more than this.
This paper is honestly a pretty easy read, not very long, and open access, so if you’re curious about the details, go check it out and look at the papers cited in this review.
Exercise
Three 15-min Bouts of Moderate Postmeal Walking Significantly Improves 24-h Glycemic Control in Older People at Risk for Impaired Glucose Tolerance | September 14, 2013
https://doi.org/10.2337/dc13-0084
N = 10
Randomized Crossover Trial
This study investigated the impact of postmeal walking on 24-hour glycemic control in older adults at risk for impaired glucose tolerance. The researchers compared the effects of three 15-minute bouts of postmeal walking with a single 45-minute bout of sustained walking performed either in the morning or afternoon.
The study involved ten inactive older adults (60 years and older) who were non-smokers, had a BMI under 35 kg/m2, and a fasting blood glucose between 105 and 125 mg/dL. Participants completed three exercise protocols in a randomized order, each separated by four weeks. Each protocol consisted of a 48-hour stay in a whole-room calorimeter. The first day served as a control day, and the second day included one of the three exercise protocols. These protocols included: 1) postmeal walking (15 minutes after each meal); 2) sustained morning walking (45 minutes at 10:30 AM); or 3) sustained afternoon walking (45 minutes at 4:30 PM). All walking was done on a treadmill at an intensity of 3 METs.2 Continuous glucose monitoring (CGM) was used to measure glucose concentrations. Average blood glucose concentration over 24 hours was the metric of interest for glycemic control (i.e., blood sugar control).
The results showed that both postmeal walking and sustained morning walking significantly improved 24-hour glycemic control compared to the control day. Additionally, postmeal walking was significantly more effective than both sustained morning and afternoon walking in lowering 3-hour post-dinner glucose levels.
The study concluded that short, intermittent bouts of postmeal walking are an effective method for controlling postprandial hyperglycemia (i.e., post-meal high blood sugar) in older individuals. The researchers suggested that the timing of exercise may be as important as the volume and intensity in managing blood glucose in older people. They also noted that postmeal exercise may be easier for older people to adhere to than longer, sustained exercise
Sleep
Multiplex influences on vigilance and biochemical variables induced by sleep deprivation | June 27, 2024
https://doi.org/10.3389/fspor.2024.1412044
N = 17 males (age, 32.0 ± 4.4 years)
Prospective observational study with experimental intervention
We all know that sleep deprivation (SD) is bad for us, and there have been many studies looking at how SD affects different biomarkers and cognitive measures, but few if any (as implied by the intro of this paper) have looked at a variety of physiological biomarkers, cognitive measures, and plasma circRNA profiles all in the same study.
They write that “circRNAs are abundantly present in [the] brain and deregulation of circRNAs has been implicated in neurodegenerative, psychiatric, and neurodevelopmental disorders” yet “the study of the function and mechanism of circRNAs in sleep is very limited and systematic understanding of the circRNA roles in sleep regulation remain elusive.”
In this study, participants slept in the lab for a night and had baseline measurements taken during the next day. The night after that, participants were not allowed to rest or sleep until after 7:30 am. All sleep-deprived measurements were taken during this overnight period before 7:30 am.
This study is chock-full of information that is difficult to summarize so I’ve copy-pasted some key parts below. This paper is open-access for anyone interested in details. The key takeaway is that sleep deprivation has systemic negative impacts on our body, particularly our brain function and immune system function. This study helped expand the knowledge base for understanding these negative effects.
Results portion of the Abstract
The volunteers showed significantly increased sleepiness and decreased vigilance during SD, and the changes in circadian rhythm and plasma biochemistry were observed. The plasma calcium (p = 0.0007) was induced by SD, while ischaemia-modified albumin (IMA, p = 0.0030) and total bile acid (TBA, p = 0.0157) decreased. Differentially expressed circRNAs in plasma were identified, which are involved in multiple signaling pathways including neuronal regulation and immunity. Accordingly, SD induced a decrease in 3-hydroxybutyric acid (3OBH, p = 0.0002) and an increase in thyroxine (T4, p < 0.0001) in plasma. The plasma anti-inflammatory cytokine IL-10 was downregulated while other ten inflammatory factors were upregulated.
The Conclusion
In this study we demonstrated that sleep deprivation can cause extensive physiological, biochemical and cognitive changes. The neurotransmitters and inflammatory factors identified in this study may serve as potential biomarkers for sleep deprivation. The findings in the present study may provide new insights into the adverse consequence of sleep deprivation and the regulation of human sleep."
Stress
Psychological problems and burnout among healthcare workers: Impact of non-pharmacological lifestyle interventions | November 20, 2024
https://doi.org/10.1016/j.ihj.2024.11.245
N = 202 healthcare providers (age ≥18) from a tertiary care medical center in North India
Prospective observational study with experimental interventions
Burnout among healthcare providers is a major issue. Yesterday I read this short article about how this is particularly a major issue among Gen Z healthcare workers. Learning how to prevent burnout and cultivate a work-life balance among healthcare workers is an important societal issue, which is likely to help inform burnout prevention in other fields of work too.
In this study, the effectiveness of raj yoga meditation (RYM) and stress management counseling (SMC) in addressing burnout were compared.
[Participants] in [the] RYM group were taught a structured module of raj yoga for three months by qualified raj yoga teacher in a group of five people, one-week offline mode, thereafter, online everyday up to 30 min. ... In [the] SMC group, subjects were introduced to a dedicated trainer. The trainer counselled and taught seven steps for managing stress one day in the offline mode for 30 min, thereafter received positive affirmations every day for a week and then once a week for three months.
To me, the difference between the two interventions seems pretty flawed. The raj yoga intervention is much more involved, so the fact that the “RYM group showed significant reduction in depression, anxiety, and stress in comparison to SMC group” does not surprise me. The yoga group also had significantly lower levels of burnout compared to the SMC group.
Perhaps most interestingly, though less relevant to our interest in understanding lifestyle health, part of this study involved training a machine learning model to predict burnout based on electrocardiogram (ECG) data that was collected from the participants. I honestly need to read the paper more deeply to try to understand how they trained this model and how it worked, but the abstract ends with the following:
ML algorithms could identify burnout patients using the raw ECG data with time-series features based classifier performing better than Ultra Short HRV features based ML classifier model.
Conclusion: AI based early diagnosis of heart’s healthy status using ECG analysis may prevent development of cardiovascular disorder in the long run.
Connection
One of the only media subscriptions I pay for is WIRED. I’m a sucker for following tech news and they do it well. Their coverage of topics that are only tangentially technology-related has seemingly expanded quite a lot and I often find some good health-related articles there. Here’s one from Christmas Day and my exposition of the research articles it cited.
Give Your Social Health a Decent Workout | WIRED
https://www.wired.com/story/social-health-relationships-community/
Relevant citations:
Almost a Quarter of the World Feels Lonely | Gallup | the article
In the WIRED article: “According to a Meta-Gallup survey, 24 percent of people worldwide feel lonely.”
Graph from the Gallup article
The Belonging Barometer The State of Beloning in America (revised edition) | The American Immigration Council | the report
In the WIRED article: “The Belonging Barometer survey by the American Immigration Council also found that 74 percent of Americans don’t feel connected to their local community.”
How Social Connection Supports Longevity | Stanford Lifestyle Medicine | blog post
In the WIRED article: “social health is linked to a 50 percent boost in longevity, making it as important to our lifespan as avoiding smoking, tackling obesity, and regular exercise.” I think this was a lazy citation for the author of the WIRED article because this Stanford article is only a secondary source for this claim, which isn’t very literally supported by any of the studies cited in it. Here’s why…
Loneliness and social isolation as risk factors for mortality: a meta-analytic review | March 11, 2015 | doi.org/10.1177/1745691614568352
In the Stanford article, this meta-analytic review is hyperlinked to the italic portion of the following quote: “While healthy networks of social connection provide powerful protective health effects, increasing odds of long-term survival by 50%, loneliness itself is associated with many distinct detrimental health impacts on sleep, physical health, and mental health.” This paper doesn’t make this claim directly though.3 It supports the claim that loneliness/isolation increases the odds of death by ~50% (unadjusted/partially adjusted sections of Table 3), which means that people who were not lonely had 50% greater odds of survival in these reviewed studies. But…
But to go back to the claim in the WIRED article, to say that “social health is linked to a 50 percent boost in longevity” is pretty imprecise. It implies that people with good social health live 50% longer than lonely people, which is not supported by this research.
Also cited in the Stanford article is the following paper, which I’ve shared twice before (read my summary here):
Social Relationships and Mortality Risk: A Meta-analytic Review | 2010 | doi.org/10.1371/journal.pmed.1000316 |
This paper more directly supports the claim from the Stanford blog about “increasing odds of long-term survival by 50%.” The abstract states: “Across 148 studies (308,849 participants), the random effects weighted average effect size was OR = 1.50 (95% CI 1.42 to 1.59), indicating a 50% increased likelihood of survival for participants with stronger social relationships.”
Finally, the Stanford blog post also references this review paper, which seems great, but I have to simply add it to my reading list for now: Characterizing the Mechanisms of Social Connection | December 20, 2023 | doi.org/10.1016/j.neuron.2023.09.012
Other
As a UChicago Alumnus (and current student), the University’s Big Brains podcast holds a special place in my heart. I’ve met the host of the show, Paul Rand, who’s a super nice guy, a friend of mine used to intern for the production team when we were in undergrad, they consistently have great guests on the show, the production quality is great, and the episodes tend to be relatively short (usually around 30 minutes).4
The episode they released last week featured Tim Stockwell, a researcher whose work debunks positive health claims about moderate drinking. The short story is this: having 1 alcoholic drink a day probably doesn’t have any health benefits and the studies that suggest it does are mostly biased or fail to adequately account for confounding factors.
Here’s the episode webpage with the transcript: Big Brains Ep. 149. You can listen to it there too, but you’re better off just searching for it on whatever podcast platform you use. Here’s the link for Spotify & Apple Podcasts.
Disclaimer: This newsletter provides health information and research for educational purposes only. It is not a substitute for professional medical advice. Consult a healthcare professional for guidance on your health-related decisions. We are not medical professionals.
Based on what I’m seeing from a quick Google search, it seems that a large Chicken Breast (8 oz.) has about 50 grams of protein, and an egg tends to have between 5 and 7 grams of protein.
“One metabolic equivalent (MET) is defined as the amount of oxygen consumed while sitting at rest...”
In this study, they write: “The treadmill speed necessary to achieve an exertion level of 3.0 METs ranged from 2.1 to 3.5 mph, with an average speed of 3.0 ± 0.4 mph.”
Unfortunately, this paper is pay-walled, but I have access through my university library.
I wish I could say this is a paid promotion but I just got carried away fanboying.