Thanks for joining me for another edition of the SerenityThroughSweat blog. This week I heard an interesting anecdote that I thought was important enough to share and discuss.
Before we get to the story, the backdrop is important. It involves something I have been practicing for the better part of three years now. Intermittent fasting (IF) or time restricted feeding (TRF).
The terms are used somewhat interchangeably in diet/health and wellness culture, but they are quite different when examining the scientific literature.
In the scientific literature (peer reviewed journal articles and studies) intermittent fasting refers to days with severely reduced or no calorie intake. For example eating normally for five days and severely restricting or entirely eliminating calories for two days.
Time restricted feeding on the other hand, refers to eating all of your calories for the day within a restricted feeding window. The most common of which is an eight hour feeding window and a sixteen hour fasting period.
This article provides a meta-analysis of the literature on intermittent fasting and time restricted feeding. That is a fancy way of saying that the authors read all the studies that have been done in the area. Evaluated their methodology, data, and interpretation. Then, decided on which studies to include.
They are not conducting the studies, but rather analyzing all of the studies together for a 20,000′ view of the landscape.
In both animal models and human trials, IF and TRF both show incredibly promising results. Decreased body weight, improved cholesterol numbers, reduced glucose, insulin, and increased insulin sensitivity, and improved inflammatory markers.
Several different studies that included feeding windows varying between four hours and twelve hours where reviewed and analyzed. The evidence on the benefits of intermittent fasting and time restricted feeding are very difficult to dispute.
By far the most popular in the health and wellness community is the right hour feeding window. This is what I (generally) practice, and it has become a dogma for some. With the results of peer reviewed science just mentioned it is easy to see why.
What I find fascinating though, is the anecdote shared by Dr Huberman on the Huberman labs podcast.
One of the earliest studies in the space, that produced the results that led to so many other follow on studies, used an eight hour feeding window. This was chosen not because of a scientific hypothesis, or even an educated guess of a reason. The eight hour window was chosen because the graduate student who was conducting the research was in a relationship.
The graduate student’s significant other made it clear that they would not be allowed to live in the lab, and had to spend some time at home. So an eight hour window, plus some set up, cleanup, and reporting time, struck this balance.
As I have noted, the meta analysis reviewed for this post covered varying TRF windows ranging from four to twelve hours. But, one of the most pivotal early studies in the space, one that the health and wellness community has certainly gravitated toward, had it’s methodology set around a college romance.
This in no way hindered the science, but it begs the question, is that the best way? The data are compelling, but what if the baseline was established at six hours? Four hours? Ten hours?
A decision was made (one I totally understand as someone who spends lots of time working away from home) to make the baseline eight hours.
I read the meta analysis, listened to scientific podcasts explaining them, and decided it was a good idea for me to try. To do my own scientific experiment with how I respond to TRF. I felt the data was compelling enough to merit individual exploration.
There has been a lot of talk in the last few years about trusting the science. The data doesn’t lie. But, the methodology is important. Asking questions, evaluating, and exploring help pave the way to better understanding, and ultimately serenity.
Thanks for joining me, stay safe and stay sweaty my friends.
