Does Fasting Burn Muscle Mass?

[SQAAD]

Firstly let me tell that i am a fan of fasting. I've done couple of water fasts so far. Jason Fung is one of the people who inspired me to start fasting for weight loss. Now i consider fasting as a weight-loss tool and a health-longevity tool... BUT i am afraid of the trade-offs...

I don't want to risk losing muscle because i know that muscle is very important for longevity especially as you age because of sarcopenia. You can basically predict how much someone is gonna live over age 65 based on his grip strength.

Recently i have been watching Layne Norton. He has a PhD in Nutrional Sciences and heavily criticizes Jason Fung's work. 

Some of Layne's video made me re-think if i wanna fast again or not. Personally i want to fast but at the same i am afraid of muscle loss. I don't know what to do besides more research.

There are some studies that show fasting burns more muscle compared to typical calorie-restriction while others don't. I think this is a tricky subject. One one hand i am afraid of getting some cancer because of not fasting once in a while and on the other hand i don't wanna lose a bunch of muscle which is gonna force me to eat less calories and be significantly weaker.

He also downplays the benefits of fasting... Maybe this is a good example of scientism.

 

Edited August 16, 2021 by SQAAD

[Michael569]

I'd be sceptical to every single thing claimed by Norton. He is notorious for being somewhat dogmatic and hiding his cherrypicking behind his PhD. 

I gotta ask this "why would you get cancer from not fasting" most people (statistically speaking) do not fast and most people (statistically speaking) do not get cancer in their lifetime.

It's a great habit that's for sure but watch out that it doesn't become a neurosis. 

The muscle atrophy questions is all about the length of the fast. 24 hour fast won't do that to you. A 72+ might but the loss won't be dramatic, we're talking grams here probably coming from your largest groups (legs). Also don't forget that your body recycles amino acids, you don't just run out, there is a constant stream from breakdown of old cells, neurotransmitters, red blood cells etc. 

In order to enter muscle catabolism there has to be a significant period of starvation. To protect yourself you can just take some amino powder twice a day on your fast.

 

 

[SQAAD]

@Michael569

2 hours ago, Michael569 said:

 

I gotta ask this "why would you get cancer from not fasting" most people (statistically speaking) do not fast and most people (statistically speaking) do not get cancer in their lifetime.

 

 

Because the odds of getting cancer are not looking that good.. 1/2 in women will get cancer and 1/3 in men.

 

2 hours ago, Michael569 said:

I'd be sceptical to every single thing claimed by Norton. He is notorious for being somewhat dogmatic and hiding his cherrypicking behind his PhD. 

 

He has made some pretty absurd statements. His worldview is purely based on science and he follows a diet where he eats whatever junk food he likes because it fits his macros and doesn't think there is any problem with that because of science. Vegan Gains has made some good points about him in the past. I think he is a good example of scientism and purely a materialistic approach to life.

 

[Leo Gura]

You will certainly slim down from prolonged fasting, and I don't mean just fat. You are not going to be able to maintain big muscles. This is why steroids are used by bodybuilders in their cut phases just before competition.

It's hard to cut fat and keep huge muscles at the same time.

With that said, unless you're a bodybuilder you shouldn't worry about being lean.

Optimize for health and performance, not macho appreance.

[hamedsf]

it will, because body will attack fat cells and then muscle tissue cells (mion) for getting energy and burning them. 

prolonged fasting is not recommended if you care about your muscle mass! 

[Enlightenment]

If 16:8 intermittent fasting helps you to eat fewer calories - it will be healthy for you and decrease the risk of cancer etc. but it doesn't do that independent of calorie restriction

As for building/maintaining muscle - science says 3 protein feedings a day is a minimum to optimize muscle protein synthesis

You can get three protein feedings during an 8-hour window

[The0Self]

6 hours ago, Enlightenment said:

If 16:8 intermittent fasting helps you to eat fewer calories - it will be healthy for you and decrease the risk of cancer etc. but it doesn't do that independent of calorie restriction

As for building/maintaining muscle - science says 3 protein feedings a day is a minimum to optimize muscle protein synthesis

You can get three protein feedings during an 8-hour window

This is correct

 

OP, I would not trust Layne Norton. Just my opinion.