Newsletter #025: The impact of diet, exercise, and sleep on health 🥬
Good day friends!
Another Saturday has arrived, and so too has the latest HumanOS newsletter! This is where we share our own work, and the interesting research and media that we stumbled upon this week. 🤓
This week on the blog, Ginny wrote about a problem that a ton of us seem to struggle with: overeating while doing cognitively demanding work, whether that be studying, writing at a computer, etc. Lots of people can relate to this problem, and research actually supports it as well. In one study, for instance, students were assigned to either a 45-minute mental work session or a 45-minute rest session. Afterward, they were presented with an all-you-can-eat buffet. Following the mental work session, the students consumed an additional 229 calories, compared to the rest group. But unfortunately, thinking really hard doesn't burn a whole lot of energy. The researchers found that the mental work session only burned a measly 3 calories more than resting.
This is a big problem from a public health standpoint, since more people than ever before make their living doing mental work, and that’s not likely to change anytime soon. But fortunately, a team of researchers may have found a very appropriate solution to this dilemma. Check out the blog to see what they found, and how you can take advantage of it yourself.
New humanOS Content and Features
• Blog: Why Mental Work Makes You Overeat, and How Interval Training Can Help. By Ginny Robards.
This Week’s Research Highlights
Researchers examined dietary data and retinal photographs from 2037 older Australian adults, who were folloed for 15 years. Incidence of age-related macular degeneration was determined from retinal imaging, and intake of dietary nitrate was calculated from food frequency questionnaires. The researchers found that people who ate between 100-142 mg of nitrates from vegetables each day had a 35% lower risk of developing early-stage macular degeneration, compared to people who ate less than 69 mg of vegetable nitrates daily.
🧘 Paternal exercise prior to conception may affect the metabolic health of their children later in life.
Researchers at Ohio State University fed male mice either normal chow or a high fat diet. Within each diet group, some mice exercised freely, and others were prevented from being physically active. After three weeks, the mice reproduced, and their offspring were fed a normal diet. The researchers observed that offspring from mice that had been fed a high-fat diet and had been sedentary showed signs of glucose intolerance. However, exercise abolished this effect, even in the fathers that had been fed the high fat diet. Male mice that exercise produced offspring that had better glucose metabolism and lower body weight. This mirrors prior research showing that when mothers exercise, their offspring experience better metabolic health. The researchers wonder if this implies that physical activity in both parents would have additive or synergistic effects on the glucose metabolism and body composition of their offspring.
Researchers analyzed data from 6845 drivers involved in a representative sample of crashes investigated by the US Department of Transportation. They divided the incidents into two groups based on whether the driver had been deemed culpable or not culpable, then compared self-reported hours of sleep in the 24-hour period before the crash. Compared to drivers who got 7-9 hours of sleep, drivers who reported having slept for 6, 5, 4, and less than 4 hours before crashing had 1.3, 2.9, and 15.1 times the odds, respectively, of having been culpable for their crashes, compared with drivers who reported 7–9 hr of sleep. The increase in odds of being culpable in a traffic accident from getting less than four hours of sleep is comparable to the level of risk associated with a blood alcohol concentration that is around 1.5 times the legal limit.
Podcasts We Loved This Week
- Mike T. Nelson: Metabolic Flexibility Revisited. Via Sigma Nutrition Radio with Danny Lennon.
- Andrew Huberman: The Neuroscience of Courage and Fear. Via the Collective Insights Podcast.
The humanOS Bookshelf
The End of Overeating by David Kessler.
Ginny says: Why do so many of us eat beyond our physical needs? In this book, former FDA commissioner David Kessler documents how lifestyle changes and constant exposure to hyper-palatable foods combined to fuel one of the largest-ever public health crises of the modern era. This book is eight years old, so there’s nothing new here, but the content holds up remarkably well, and it is a very accessible introduction to the science of food reward and the background behind the obesity epidemic.