A Short Thanksgiving Walk
Thanks to each of you for your support! I'm grateful for your time and interest.
Thanks also to those of you who forward links. Folks have recommended that I use social media to promote the newsletter, but word of mouth (more precisely, word of internet) seems to be working fine.
This week's edition is brief. I want to talk about the health benefits of taking a short walk after Thanksgiving dinner (or any dinner, for that matter).
You might say that this newsletter is a short walk through the topic of short walks.
My topic was prompted by an article on the New York Times home page this week entitled "Just 2 Minutes of Walking After a Meal Is Surprisingly Good for You." The subtitle refers to a "new paper", though it turns out that both the article and the paper were written last year.
No matter. The topic is of perennial interest. And, for thousands of years, the advice has been pretty much the same: Move around right after you eat. According to an ancient Chinese proverb, "Walk 100 steps after a meal and you'll live to be 99."
If you're eating with a Mandarin speaker, just say the first part of this proverb and they'll get you ("fawn hoh bye boo dzoh").
If you're etymologically inclined, the character for "walk": 走, pronounced "dzoh", evolved over thousands of years from a pictograph of a person running (see below. That little branch-like thing under the running person is the character for "stop".)
We'll never know who created this character or why it's written the way it is, but I like to think the implicit message was: Take it easy. When you move around, just walk, don't rush.
Anyway, having a walk after eating is sensible advice, but it's worth finding out whether the data agrees. After all, health practices that kick around for thousands of years aren't necessarily good for you (e.g., bloodletting). Plus we might want to know how long we should walk, and what the payoff is.
New data
The New York Times article I mentioned referenced a 2022 meta-analysis of seven studies on the impact of standing and low-intensity walking following a meal. The lead author was Dr. Aiden Buffey at University of Limerick, Ireland. Participants were all described as overweight or obese.
The studies relied on the same basic procedures: Participants came to the lab, sat for roughly 20 to 30 minutes, ate food provided by the experimenters, then stood or walked for 2 to 5 minutes as per experimenter instructions.
(This kind of research definitely has a Thanksgiving vibe: Lots of time spent sitting or eating!)
Although the studies differed in exactly what participants ate, how long they sat, etc. the data revealed some clear patterns:
–Standing after eating reduced blood sugar levels more than sitting did.
–Walking after eating reduced blood sugar levels and boosted insulin more than standing did.
Key to these findings is that the changes in blood sugar and insulin levels after walking were assumed to be the right amounts – not too much, not too little.
(You want spikes in both after a meal, as the insulin helps move glucose from the bloodstream into your cells, where it provides energy. But if blood sugar remains too high for too long, the risk of diabetes increases, and plaqus builds up on blood vessel walls, impairing their ability to expand and contract normally and eventually causing heart disease.)
So, a short walk after eating seems good for your health. That 2-to-5 minute statistic is especially good news, in my opinion, for several reasons:
–It's not much time!
–Evidence-based recommendations for walking are often framed in terms of "going out" for a walk. That's not helpful advice when the weather is bad, or you don't feel like getting dressed, or walking in your neighborhood happens to be dangerous or unpleasant. However, you can walk for 2 to 5 minutes anywhere, even in a tiny apartment. (All the studies were conducted in labs, so there's nothing about fresh air that's essential to the effects.)
–You have a window of about 60 to 90 minutes after a meal to get your 2 to 5 minutes in, as that's the time when blood sugar spikes (and when adjustments are most needed if the spike is too high).
Final thoughts (bad news, good news)
The studies I just described looked at biochemical changes occurring on one day under controlled conditions. They don't offer direct evidence about the long-term benefits of walking after meals.
Studies that follow people over time can directly examine links between walking and health, but they're messy. We can't measure the precise details of peoples' daily walking and eating behavior over a period of decades.
Concretely speaking, you can either bring people to a lab and control their walking and eating behavior for a day, as in these studies, or you can interview them about the topic once a year or so for decades.
In the end, what these and other approaches give us is a sort of buffet of uncertainty. Every methodology has its own particular flavor.
Still, there's value in considering what the best of each kind of study tells us.
For instance, in a prior newsletter I suggested that the perils of sitting in one place for too long can be offset by occasional breaks, even if it's hard to say exactly when or how long to get up and walk around.
As for how much to walk per day, that 10,000 step advice originated in a marketing ploy, but studies do show that some lesser amount is healthy.
Taken together, these studies suggest that a little bit may go a long way. Walking a little, especially after meals, seems to be good for you.
Happy holiday, and thanks for reading!
(Photos courtesy of the wild turkeys that own the streets of Cambridge MA, occasionally stopping traffic.)