I do do IF but not interested in a day or more of fasting and very interesting report from Virta here
http://blog.virtahealth.com/science-of-intermittent-fasting/
Now if you are aware Virta is my heroes in this field Steve Phinney and Jeff Volek and this kind of compares to what Dr Adam Nally has said as well.
As these are Keto heroes then this is not about knocking fasting but the science and we know Phineey does science like no other, thoughts @richard @carl @Brenda
I look at the success of Dr. Fungās patients. Hard to argue with that. Still, I will read this with great interest.
āIt is also worth pointing out that people do not carry around āextraā protein stores held in reserve doing nothing ā just waiting to fill in for the day we donāt eat enough dietary protein. All protein in the human body has a real-time function, be it muscle, connective tissue, red blood cells, brain, or antibodies. So whenever the body loses protein, it loses some of its functional reserve.ā
This statement denies the existence of autophagy.
well this is an opportunity for a Fung vs Phinney debate ?? for me as I said fasting is not a big deal so unlike others I do not care for longer fasts but for IF I read it with great interest.
For all of Phinneyās attributes, Iāve seen him over-generalize and project into the future in ways that are demonstrably untrue, i.e. his claims about how much needed lean tissue is lost, day-by-day, when fasting - witness the famous case of the guy who fasted for 382 days, and the accounts of fasting for 60 and 44 days on this forum.
I agree that autophagy can in theory be a double-edged sword, yet I think itās alarmist to say,
āAfter just one day of fasting, you begin to lose body protein from lean tissue ā from places like muscle, heart, liver, and kidneys. These organs and their functions are things that we want to preserve, and definitely should not be given up lightly. So while you may lose weight according to the scale, part of it will be at the cost of your important, metabolically active tissue.ā
The guy who fasted for 382 days went from 456 lbs./207kg. to 180 lbs./82kg. and was fine, and maintained close to that final weight for years afterwards. Itās not like his heart muscle went away.
Totally agree that we excrete nitrogen during fasting, yet that does not necessarily mean that vital structures and cells are being harmed. Our skin accounts for almost one-sixth of our weight - right there is a huge source of ālean body massā and as we lose skin that excreted nitrogen will show up. Losing skin while fasting definitely happens for many people. Not sure about what percentage of people this is true for, but there is a common theme of people who fast not having the loose/saggy skin as do many who lose weight by calorie restriction or other non-fasting means.
Hey, Iām in the 9th day of a fast right now, and I want to know. No doubt we āuse stuff upā when fasting - the Noble Prize-winning work of Yoshinori Ohsumi and others proves it. Yet where is the science that actually says that fasting beyond 24 hours damages our organs?
A lack of autophagy - our cells not getting rid of pathogens like viruses and bacteria, damaged and diseased cellular components, and other harmful materials - is what leads to neurodegenerative diseases like Alzheimerās and Parkinsonās. The breaking down of proteins into amino acid components is what our neurons do - otherwise the proteins become toxic, and autophagy is how they do it.
The above is my main disagreement. On slowing metabolism - I do believe that the body will āturn down the thermostatā to conserve energy, in the long run. However, here I am, fasting away, and my hands and feet are as warm as ever, and Iāve felt no sluggishness, tiredness, etc., of any kind.
Dr. Fung maintains that fasting does not result in the slowing of metabolism, as does calorie-reduced diets. For me, anyway (and thus far), that seems to be true.
Well said! I agree. In a non-scientific observation, if fasting is so bad for the body, why do I feel so fantastic?! Why is my body thriving? Why is my mind sharper? Why did a ketogenic alone not work after 2 years of trying? I agree fasting should not be done lightly especially when you are taking medication, but the statements made by Phinney seem ridiculous! I would be a puddle of fat with no muscle or energy if fasting was a detriment to my LBM!
Can we get more science to dispute this? Because I am a die hard faster but this is saying I am hurting my body and thatās the last thing I want to do!
I have nothing but respect for Phinney and Volek and I am a bit skeptical about fasting BUT this seems like sloppy science and I need to call it out just as I would the sloppy science supporting high carb diets.
The āold but excellent human researchā, dollars to donuts, was done on non-keto adapted subjects. It likely has little relevance to people who have completed the keto adaptation process.
This data does clearly show why people should not fast unless they have gone thru the full keto adaptation process.
Also - why is there the assumption that Nitrogen loss is definitely protein loss? It seems misleading. Whereās the science saying this is definitely muscle loss?
How is 300 kCal/day considered fasting? All the fast studies referred to were supplemented fasts.
Sorry there are just so many questions!
Indeed - I thought of this at the mention of the āMinnesota Starvation Experimentā - this was just calorie restriction. This was not fasting.
I question even this, Ross. Anecdotal, but I was never even remotely keto-adapted until this year, and had fasted for two days quite a few times (just the way things worked out) and once for six days in 1981, and didnāt feel anything ābadā at all. Okay, somebody is a carb-burner. They fast, their blood glucose goes down, their glycogen stores get depleted, and then they start the adaption to burning fat. What, really, is the harm?
Hi Doug!
Good question.
My limited understanding is that prior to being fully fat adapted, our bodies only have limited access to the energy in our stored body fat so the body is likely to respond by reducing metabolic rate to match reduced available energy.
Post adaptation, we have access to nearly unlimited energy (FASTER study showed mind-blowing fat oxidation rates) so the body has no reason to reduce metabolic rateā¦might even crank it up a notch.
I think the parable of the blind men touching different parts of an elephant is illuminating here.
Phinney and Volek have studied different patient bases than Fung. It is expected they would have different results and therefore arrive at different conclusions. A middle aged, obese T2D and a college aged athlete with 15% bodyfat are not likely to respond to interventions similarly. If the former does prolonged fasting, it is likely to improve their health on every front. If the latter fasts for extended periods of time, they will likely lose muscle.
Long term fasting isnāt for everyone. Itās a drastic intervention for people who have severely deranged metabolisms. And like all medical interventions, there are risks associated with it. But in the appropriate cases, the risk may be worth it.
Someone who has good biomarkers and just wants to lose 20 lbs can achieve that with IF, there is no need for extended fasting. Someone who is insulin resistant and 100 lbs overweight may need to fast for longer periods of time.
Both scientists are right. Itās a matter of which protocol is appropriate for you.
I think Phinney and Fung can both be mostly right at the same time. The bodyās protein is consumed during extended fasting, including lean muscle mass, but weāve evolved to do this in a fashion that has minimal impact on long term health and is likely beneficial for most people except in extreme cases of starvation.
Consider the n=1 fairly extreme example of actor Christian Bale who in preparation for the movie āThe Machinistā for 4 months went on a near starvation diet of just an apple or a can of tuna a day and dropped from nearly 180 lbs to between 110-120 lbs. In several scenes the camera dwells on his emaciated frame and his muscle loss was such that he said the running scenes were very difficult. But two years later he is playing Batman with a body fit for the role. He clearly didnāt fear the dangers of fasting induced muscle loss and was apparently able to reverse whatever damage was done. Heās undertaking a new scarier to me challenge of a role playing Dick Cheney and heās eating a lot of pies in preparation. I hope the recovery goes as smoothly as it did for the near starvation.
I am not sure we know enough about autophagy to say it works almost exactly like the protein we ingest in repair processes. Iām hearing that people are claiming they are interchangeable, as in, āIf I donāt eat protein the by products of autophagy will provide the materials to do the work dietary protein does.ā Iām skeptical about autophagy being a kind of panacea. That said, I think there are drawbacks to extended fasts people in the keto community donāt always want to talk about, especially the psychological of engaging in longer fasts for extended periods of time. I think itās prudent to no place too much emphasis on any one mechanism as being the end all be all for resolving health issues.
Erin, Iād think that it would work well - the amino acids required for human life are what went into the protein structures that are being recycled and broken back down into amino acids. Everything necessary should thus be there.
Totally agree. (For one thing, all this thinking about fasting, diet and food is making me almost achingly hungry. 
) There is a woeful lack of research and knowledge about it, to be sure. At the same time, trials are being done on drugs that start autophagy in the body, due to their promise of being cancer treatments, etc.
Iād be interested in hearing about those drawbacks. Never have heard any. I know that fasting isnāt for everybody - plenty of tales like āI got to that second day and said the hell with this!ā Yet I think you are talking about longer-lasting things that persist after one begins eating again.
This is true - I suspect that in other than extreme cases (true starvation, or intended weight loss well beyond just losing unneeded fat) - most people are just fine, and for a long time, while fasting.
I respect Dr. Phinney, but he himself has admitted that he is biased against fasting and has never really studied it besides looking at existing literature.
Iāll go with Fung who actually has clinical experience with it.
Most likely it is, though there could be another explanation. However, protein loss is not the same as muscle loss. There are lots of tissues made up of protein that are not muscle and become redundant when weight is lost ā skin and connective tissue for example.
Also, Phinney doesnāt acknowledge that because of the increase in growth hormone, the body rebuilds needed tissues very quickly after the fast ends. Thatās an important point that is often forgotten.
Finally, experiments with dogs that I came across in a Soviet book on fasting showed that even at death, when all fat was gone and the body had started cannibalizing itself, vital organs like the heart were still practically untouched at only 3% loss of mass. Other organs less immediately vital had more loss, but it shows that the body is not stupid (like Dr. Fung likes to say).
I agree as well. Sure protein loss occurs with fasting. I am hoping the excess protein in my excess skin goes away soon
It is also worth pointing out that people do not carry around āextraā protein stores held in reserve doing nothing ā just waiting to fill in for the day we donāt eat enough dietary protein.
There is a small storage reservoir of protein in the body called the labile store of protein, which is roughly 1% of our total lean mass. But itās not in a purely storage molecules like triglycerides, glycogen, or betahydroxybutyrate (respectively storing fatty acids, glucose and acetoacetate), itās mostly protein structures deployed for uses that can be easily redeployed ā¦ eg: circulating lipoproteins like albumin, and LDL, and old tissue just waiting for a quiet period to undergo normal apoptosis.
We also have the ability to make many amino acids from metabolic raw materials, reclaiming nitrogen from circulating levels of urea. So in the initial days after a fast our net nitrogen loss will be reduced as we become nitrogen sparing.
- Rabast et al, 1981.
Total fasting was compared with a 300 kcal/day very low calorie diet providing 56 g protein and 12 g carbs in 14 healthy obese patients, selected as matched pairs, over a period of 28 days. The weight loss was significantly greater during fasting than during the VLCD (16.5 kg vs. 12.7 kg). The basal metabolic rate showed a significant decrease (25 per cent) during total fasting, but was unchanged with the VLCD.
Dr Phinney is right that healthy obese people who fast for 28 days have been observed to eventually see a 25% reduction in resting metabolic rate [ https://www.ncbi.nlm.nih.gov/pubmed/7275468 ]. I suspect a lean person who fasts would see something similar after their circulating elastic capacity is drawn down - say after an 18 hour fast.
A type 2 diabetic with adequate body fat reserves who fasts may well have a greater energy surplus, as their access to their stored energy is no longer constrained by elevated insulin. Iād like to see some metabolic cart studies into fasting subjects (lean insulin sensitive, and overweight insulin resistant) and put some real data and contexts on this question of what happens to your resting metabolic rate when you fast and how that changes over time.
Is Dr Fung correct that metabolic rate increases over the first few days to increase the likelihood of a successful hunt? And is Dr Phinney correct that the body adapts over longer periods to become energy sparing?
I didnāt know about [ https://www.ncbi.nlm.nih.gov/pubmed/2104036 ] which suggests based on Dr Phinneyās interpretation of his own study that a protein level of 1.5 g/kg is more protective of function than 1.2g/kg
Compared to baseline, VO2max and peak quadriceps strength declined on the 1.2 g/kg protein dose, whereas both of these functions were preserved at the 1.5 g/kg level.
I found it interesting that the lower protein arm also had 3 times the carbohydrates of the higher protein arm (30 vs 10g/day) and while the statistical significance for the results of the lower protein higher carb arm were just significant (VO2 max 2.44 - 2.06 l/min) the results for the higher protein lower carb arm were just below the level of significance (2.16 - 2.01 l/min). With the carbohydrate confound and the closeness of the results I suspect his interpretation may be a little generous to his narrative.
The amount of lean tissue you have is a strong determinant of your resting metabolic rate. Interpretation: your total muscle mass is your furnace ā the more muscle you have the faster you can burn energy.
Interestingly Dr Phinney did one of the experiments that shows that resting metabolic rate is dynamic and determined by energy budget (which will include supplying energy to lean mass). [ http://www.metabolismjournal.com/article/0026-0495(88)90011-X/abstract ] Where he locked 12 obese women in a metabolic ward, fed them slightly hypocalorically so they were under modest energy constraints - then had half of them run on a treadmill up to 2 hours, and the others just sit on the couch watching TV. After 5 weeks he weighed them and the couch potatoes lost a non significant amount more weight because the exerciserās metabolic rates were down regulated for the 20 hours in the day when they were not on a treadmill to account for the increase in exercise demand for energy.
In general I agree with Dr Phinney that not getting adequate protein is a serious problem. He mentioned to me when he was in Sydney recently - In the 1970s there was a liquid protein fast (basically jello shots) that was nutritionally inadequate and killed several people but because they coincidentally get people into a state of ketosis - THAT damaged the reputation of ketogenic diets for decades and dried up all funding right at the most important phase of his career. So I get why he is concerned. Heās too old to have to go into the wilderness for 4 decades again.
But there is also the problem of diets that advocate unsafe levels of too much protein. There are plenty of people around the internet recommending eating 4.4g/kg LBM and up ā¦ and there is research [ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC333026/ ] showing that healthy people can only deaminate about 3.31g/kg LBM of protein a day before they saturated their ability to dispose of the ammonia ā¦ and that has killed 2 people in 2017 alone.
This is why I believe that Ketogenic diets should actively avoid being associated with high protein fads. Diabetics who need the option of ketogenic diets to reverse their disease also can not go back into the wilderness for 4 decades.