I'm seeing a trend that people want to hear more on fasting and its impact on muscle loss, as well as metabolic rate (from long term fasting) - I'll see if I can't cover those topics in the future for you. Thanks for chiming in, folks!
One thing to consider is that they were doing a long 10 day fast. I also wonder if they were allowed to exercise during that time? Had they done 48 to 72 hour fasts once per week with eating resumed in between, the fat loss would've still been better and they would've retained more lean muscle meas. I do think that 48 to 72 hours is the SWEET SPOT for fasting without losing muscle
It could very well be, but one needs to test that to be sure - we can't assume based on what we want the answer to be :) . Also, those broken proteins are removed by autophagy and the proteasome.
@@Physionic This is true. I'm all for an unbiased approach when it comes to seeking the truth no matter how I personally feel about it. Thank you for your reply.
On point nick. I lost about 15kg with intermittent fasting and i actually gained a bit of muscle mass because o was doing heavy weights and i would open my fast with a protein rich food. I know its only possible in the beginning but i managed to take advantage of it.
_Autophagy_ : The natural, conserved degradation of the cell that removes unnecessary or dysfunctional components through a lysosome-dependent regulated mechanism. It allows the orderly degradation and recycling of cellular components by prolonged fasting.
I’d like to see the follow-up to this study, because fasting does activate some different metabolic pathways than calories restriction does and, while calorie restriction often leads to stomach shrinkage, fasting does the opposite as people usually fill up in more food when they can eat. So I do wonder which is more sustainable after the diet is over
@@Physionic Thanks! I'm actually doing research on fasting and calorie restriction in mice right now, and it's very interesting. Not necessarily applicable to humans, but I really would love to see you browse through some human-related research on this
@@rvoloshchukify That’s really cool. Keep me updated. It can have some mechanistic information that may be applicable to humans. All the best with your research!
All weight loss reduces metabolic rate; fasting may have a slightly worse effect in that regard, but I'd doubt its anything noticeable. This is, of course, assuming we're talking years.
According to this study, the amount of fat lost in 30 days of fasting is equal to the amount of fat lost in a 45-day 800 kcal diet.(with the less protein lost) The second one seems much more sustainable to me.
I must challenge the drawback, at least partly. If fasting results in muscle breakdown about double the amount compared to calorie restriction, we have to remember that the weight loss is also not far from being two times faster. This means that for the same weight loss, the ratio is quite close. I tried to come up with the numbers, but my calculations were so far off from what you said that I gave up on calculating the difference.
So the extra protein energy could be coming from protein breakdown via autophagy outside of muscle tissue, which is what many people are chasing, myself included.
@@Physionic Thank you, just coming up on 53hrs and it's effortless. No doubt for me that going into a prolonged fast fully ketone adapted makes all the difference.
We are too much focused towards quick diets to reverse years of errors. Fasting gave me great results years ago but now not anymore. One should consider the starting point, the hormonal balance
Interesting. I'm inclined to say it always works, especially if you are not consuming anything, but I could see how intermittent fasting can trip people up.
Megan Ramos - partner of Dr. Fung - talked about protein use by the body at a low carb conference. IIRC the amount of protein recycled by the body on a daily basis is on the order of twice what you take in. Isn't that what autophagy is all about? Which should increase on a water fast.
Right. Water fasting would likely increase the amount of autophagy ongoing relative to the calorie restricted group. I'd also venture to say they'd have more protein recycling, but it seems close minded to think the body is in a greater catabolic state in all the "good" ways, but then stops short of losing muscle protein. That ends up int he realm of "I like my muscle, so my body might like it too, so I'm sure it's preserving it while washing away all the bad things I don't like." - ha! It happens a lot. Fasting is a fantastic tool and has advantages all around, but it is not ideal for muscle growth or maintenance if done incessantly. So, I agree with her, but I wouldn't buy that it explains all of the added protein loss.
Very interesting study! I did notice (what I think is a small mistake) in your video however. The total lean mass loss per fasting day is not just 6,7 grams a day as you state in the video. In the graph it is presented as 6,7% of the total weight lost per day which ends up as 0.067x750g= 50,25g a day of lean body mass loss per day. (That is a loss of 0,5Kg in 10 days if the loss progression is linear) Because of this the relative difference in lean mass loss between fasting and (extreme) diet would also be more pronounced. Please correct me if I am wrong. P.S. Maybe the lean mass loss would also explain the increase in water loss from 37% to 60% during fasting? Edit: The diet lean mass loss per day was 0.034×278g= 9,45 grams a day it seems
So the optimal thing would be do a fast once or twice do a two week maintenance and then do pretty much a lifestyle change of just being low cal Then maybe bumping up cal while doing daily 16 hr fasts. Obviously eating nutrient dense food. Bc you cant just reduce everything the meal you do eat needs to be like rocket fuel and clean compared to gallons and gallons of 87 regular youd put in a minivan. And having not a cheat day but a cheat meal once every two weeks to spike your metabolism maybe but still not junk food so its not really a cheat. But like go to a buffet and eat less healthy meats and carbs but obviously not candy and sugar so your protein is still very high. But at the same time you dont wanna stretch your stomach back out after you did all that work of shrinking it to feel full earlier.
I'm confused by this one, doesn't this just boil down to "eat less calories, lose weight quicker"? As say you're fasting, vs a 500 calorie diet vs a 1,000 calorie diet, is the rate of weight loss proportional, or is there something magical about fasting... Also, 8% of the calories came from "other cells", couldn't this be from autophagy?
Would adding an EAA help with sparring muscle loss? And what about an intermittent fast with a calorie deficit? Wouldn't that get the best of both worlds? Nice vid btw :)
EAA might help, but then you aren't fasting :) I don't believe the improved weight loss and fat loss are due to anything but the calorie deficit, so IF might help preserve some other benefits, but IF with a calorie deficit would be inferior to water fasting, since water fasting is the maximal calorie deficit one can achieve.
Protein doesn't always mean skeletal muscle though. I wish we could find out what percentage of this was coming from skeletal muscle and what percentage was coming from other protein sources in the body. Do you know of any study that talks about this at all? We all want to minimize skeletal muscle loss. Does does fasting cause the body to prioritize other protein sources first? What are some of those sources? And how would the prioritization of protein utilization change between the fasting and non-fasting groups? Being that contractile proteins are the largest store of protein on the body I would assume the majority of protein utilized comes from them in both groups, but I would be interested to know if the distribution of utilization would be different in the fasting group versus the very low calorie group. Do my thoughts make any sense at all here?
Well, that's why you don't go 10 days fast all the time😅..Also if that 800 kcal are used in one meal is completely different story too..also..what kind of proteins are utilised in longer fasts with priority, not entirely the muscle I think ?!
Absolutely, it's way more than muscle. Literally everything in your body has some protein in it. Your bones use protein, your lungs, spleen, liver, marrow, etc - just name a tissue and it definitely uses protein.
No. Protein turnover is constantly ongoing. If that were true, people who fast a month wouldn't lose any muscle, and while the body does preserve muscle well, we still see some loss after such a long time. Overall, it's not a huge worry, because the effect is mild, but I don't agree that there's no muscle loss whatsoever.
wouldnt it(water fasting) dramatically slow down your metabolism and in the long term gain more weight than on the baseline ? is there any evidence of that being the truth ? otherwise nice video and thank you very much for these videos
I had the same question myself but I think that fasting wouldn't significantly decrease metabolic rate since your body wouldn't be "deprived" of calories but rather just "not fed" Usually the metabolic rate drops in a contest of very low calories rather than a contest with 0 calories, that's because it adapts to the input. But if the input is 0 it has no chance of adaptation I may be 101% wrong on this, this is just what I think
I wouldn't worry about that too much. If you lose weight, your metabolism will diminish a small amount - but, that isn't specific to water fasting. The loss of muscle is likely nothing to worry over too much (as I'll explain in future content), either.
Once again this study , no fault of yours, didn't look at what happened, say, six months later, one year two years later. Who kept the weight off better? How fast and how much pale in my mind to whether the protocol actually gets the person more willing to live with less consistently.
I have one question .. do u think beieng in a fat adaptation mode before fasting will help reduce the protien breakdown when fasting ..also ..from my experience ..i noticed when i fast for 72 hours ..my muscle glycougen and muscle strength come to normalize after refeeds ..So from your experties ..what do you think is happening in my situation ?? ..oh forget to mention that my refeeds are carnivore and i lost a ton of wieght doing this
Omar, long term fasting tends to lead to greater protein breakdown, regardless of being keto adapted. As for your second point, that's not surprising - refeeds, especially over a day or two, lead to a rebound in glycogen.
That's correct, but protein consumption is also muscle sparing. I imagine consuming protein is more potent, long term. That said, the results don't necessarily dictate that loss was from muscle, necessarily.
@@Physionic This guy by the name Dan Phoenix went on the carnivore diet and couldn't put on weight eating up to 300 g of protein per day. How is that possible? What was going on preventing him to gain weight? If the body needed carbs as well wasn't it getting it from deamination?
