T Nation

Time Restricted Eating

Coach have you done any research on time restricted eating? There is some people saying you can grow more muscle regardless of exercise if you restrict eating within a 9-12 hour window.

Just interested in your thoughts.

Thank you.

Well, considering that I have been using intermittent fasting on and off since 1999, when T-nation first published the article “The Warrior Diet”, I can say with certainty that I have good knowledge and experience with Time Restricted Eating.

I believe that from a health perspective the benefits are absolutely real. They are in large part due to an increase in AMPK activity which has a myriad of benefits ranging from autophagy and anti-aging to reducing inflammation and improving insulin sensitivity.

I also believe that it can be a tool that make it easier to get leaner. First because AMPK helps with fat use for energy but mostly because unless you are a binger, it is easier to establish a caloric deficit when you don’t eat as many meals.

I would not call 12 (or even 9) hours Time Restricted Eating though. Being allowed to eat for a 12 hours period is essentially exactly how most people eat. Let’s say that if you have your breakfast at 7am, it means that you can eat util 7pm… how exactly is that time restricted eating?

Heck, even 9 hours… have breakfast at 7am and your last meal can be at 4pm… or breakfast at 8m and last meal at 5pm… this isn’t really restrictive at all.

On top of that, most research on intermittent fasting talking about the biggest benefits occurring when you are fasted for 18 hours (hence the 6 hours fed window or the 6-18 recommendation for most intermittent fasting systems).

But most people do not understand what “fasted” and “fed” means.

Fasted doesn’t mean “not eating”. Fasted means that you no longer have nutrients to absorb in your system.

If your last meal is at 6pm, you are not fasted at 6:01… not even at 7:00, probably not at 8:00 either… depending on the content of of the meal it could take you several hours to fully absorb your meal. If you eat a rich meal at 6:00pm, you might become “fasted” at midnight.

I see a lot of people doing the “easy” intermittent fasting approach: They have their first meal at noon and their last meal at 6… you know how I call that? Skipping breakfast, which is something that millions of people around the world do… and it’s not exactly working so well.

Again, this neglect the fact that the last meal will take a while to digest AND that the metabolic processes slow down at night. An hour fasted during the night will not have the same impact as an hour fasted while you are active during the day.

To reap most of the benefits of a intermittent fasting approach, you need a significant of your fasting period to be occurring during the day, while you are physically active (this will lead to a greater AMPK activity). In fact, the more of your fasting time can be done while you are awake, the better it is.

When I intermittent fast my first meal is at 5pm and I will have a second one at 7pm. That’s it. That is the Warrior diet day.

You could reverse it and eat at 7am and 10-11am and then stop eating. But in both cases the common theme is a long fasted time while you are awake.

As far as intermittent fasting being superior for muscle-building, I absolutely do not agree.

You can still build muscle on intermittent fasting. And if you really know what you are doing, you can gain just as much muscle as someone eating “normally” if the caloric and nutritional intake is the same. But you will not build more.

And I know because I’ve been using this approach to dieting for 21 years! And I can honestly say that I gained muscle at a slower rate when doing intermittent fasting. But it had other benefits.

You will find some studies performed on sedentary individuals (who do not train, are not physically active and are often overweight) gaining lean body mass when doing intermittent fasting. But this is mostly because these people have poor insulin sensitivity and likely a poor hormonal profile and by improving both factors you can have a slight shift toward more lean mass and less fat.

But it will not work past these initial changes and it will not work on people who are already training and are physically active. I’d like it to work, because that’s how I like to eat, but it doesn’t.

There are benefits to intermittent fasting when it comes to muscle building… for example it can increase (over time) stem cells, which are required to repair muscle damage from training. You can also get an improvement in insulin sensitivity, which is positive or muscle growth. You can also get a surge of anabolic hormones during the fed state, especially if you use a large food intake in a short period… insulin and IGF-1 will be especially elevated, and you can also get a good mTOR release during the fed period, if you eat a lot. All of that is good for muscle growth.

But there are also factors that have the opposite effect. During the fasted period cortisol will be higher (it is needed to mobilize stored energy), mTOR will go down (because AMPK goes up and inhibits mTOR… this is great for anti-aging, not for muscle growth) and it can be harder to get the same amount of nutrients in as you do with a normal eating pattern.

Both pretty much cancel each other out making an intermittent fasting similar to a normal eating pattern when it comes to building muscle.

So to recap my opinion:

  1. An eating window of 9-12 hours is NOT intermittent fasting/time restricted eating
  2. TRUE intermittent fasting has many health benefits and can make fat loss easier
  3. You CAN build muscle with intermittent fasting BUT it has no advantage in that regard vs. a normal eating pattern in healthy, active individuals.

I also wrote this:

Thank you that was very informative. As a Type 3 fasting has been a challenge the times I have tried it. I will likely give the Primer 52 program a try someday because it peaked my curiosity. Thank you again for taking the time to reply.

@Christian_Thibaudeau, could you give an example of what those two meals would look like?

yes i wanna know this too ! that was my question.

and are you workout near your 2 meals or it doesnt matter ?

Both pretty much cancel each other out making an intermittent fasting similar to a normal eating pattern when it comes to building muscle

Given that they cancel each other out, wouldn’t intermittent fasting still be the optimal approach since you get its health benefits/fat loss benefits while still being able to build muscle normally?



Are Sublingual supplements or IV supplements able to break the fast? If they are not passing though the digestive system and they don’t rise insulin.

And I’m concerts with some supplements like indigo in such small window.

If you break the fast in this scenario:

200 pm 6 indigo 6 micro pa
245 pm 1/2 servings of Plazma
300 pm workout 1-2 servings of Plazma
430 pm finish the workout
500 pm 2 servings mag10
600 pm diner (only one mal)

You should take more micronutrients so you can increase the density using superfood and other supplements like Rez-V and the customize blend someone for antiaging purpose want to take.

If the active life of indigo is 4-6 hours, doesn’t it matter take the antioxidants in the last meal? I mean I want the active action of the indigo during the workout although its activity is impaired in the last meal. Am I right?