Presuming you read the linked study but more or less (and this is argument fuel among The Faithful here ), "time restricted eating" spoken of here is Intermittent Fasting. The "restriction" here is that not a single calorie of anything is consumed outside of an 8 hour window and the 16 remaining hours in the day are nothing but water. Some people even like to do a 18:6 split too.
The hacks in this style of eating is that once you stop putting calories in your mouth, your insulin levels drop and that makes the fat cells in the body more willing to allow lipids into the bloodstream where the liver can make Ketones out of them - hence the term "ketosis" is often seen when reading about intermittent fasting.
There are also small studies, I'd call them anecdotal yet still informative, that demonstrate a raise in GH in response to an IF style eating pattern. Leptin sensitivity/resistance is also positively impacted by this eating style.
If you want to go down a rabbit hole and really geek all the way out on a topic, theres a lot out there to sort through, debunk and sort into useful information. I encourage you to give it a look.
EDIT: For extra credit - it's natural to look at Fasted Training in the same context. The hack here is that when you train at near peak low insulin levels ( or near peak anyhow which takes about 14h of fasting ) your body will suffer in terms of absolute performance but if done correctly you can train burning mostly fat. Theres as much on this subject to sort through as the first one. A whole host of hormonal and health benefits are purported here and I can say from experience I believe most of them having seen it myself.
> EDIT: For extra credit - it's natural to look at Fasted Training in the same context. The hack here is that when you train at near peak low insulin levels ( or near peak anyhow which takes about 14h of fasting ) your body will suffer in terms of absolute performance but if done correctly you can train burning mostly fat. Theres as much on this subject to sort through as the first one. A whole host of hormonal and health benefits are purported here and I can say from experience I believe most of them having seen it myself.
I've done quite a bit of fasted training, but can't say I have seen a huge effect myself. That said, I was very fit at the time, most studies have been done on untrained subjects AFAIK. There are also studies that show that base metabolic rate increases after fasted training, but for men only while it decreases for women, which would be counterproductive if they would want to loose weight.
The main problem with most of the studies is that they have been done with very small study populations.
> I've done quite a bit of fasted training, but can't say I have seen a huge effect myself
I've tried it and haven't seen much of a difference in weight loss either. Also I have only been able to pull it off with cardio - any fasted training involving weight lifting has been a dreadful experience. I've completely abandoned the idea.
A lot of people (including me in the past) have used the term intermittent fasting to describe this, but it's not a good label for this. Intermittent fasting should describe protocols where one fasts for at least a full day. If one is eating daily but only during certain hours, it's better described as time-resricted eating. It's also possible to do both time-restricted eating and intermittent fasting.
In the most medical-establishment-adjacent space I could find in serious metabolic/longevity experimentation/ research, Peter Attia's podcast, the host talks about monthly 3-day fasts as an entering argument for decent garbage collection functioning (autophagy) that would potentially suppress/inhibit cancerous growth.
