My comments in purple
Email from Peter Attia 2-17-19 (I have edited with highlights and list)
I read an interesting article authored by my friend Dom D’Agostino
and his colleagues on the anti-catabolic effects of ketone bodies in skeletal muscle.
Does anti-catabolic equal anabolic ?
Some definitions from wiki:
"Catabolic Reactions. Catabolic reactions (also called “catabolism”)
break down larger, more complex molecules into smaller molecules
and release energy in the process.
The smaller end products of a catabolic reaction may be released as waste or they may be fed into other reactions". wiki
"Anabolism is the process by which the body utilizes the energy
released by catabolism to synthesize complex molecules.
These complex molecules are then utilized to form cellular structures
that are formed from small and simple precursors
that act as building blocks." wiki
They note that we’ve already known about anti-catabolic effects of ketones
including attenuation of
1-glycolysis,
2 hepatic glucose output, and
3-adipose tissue lipolysis.
Web results
Definition from wiki
Lipolysis /lɪˈpɒlɪsɪs/ is the breakdown of lipids and involves hydrolysis of triglycerides into glycerol and free fatty acids. Predominantly occurring in adipose tissue, lipolysis is used to mobilize stored energy during fasting or exercise.
This statement by Peter is really confusing to me. Obviously I must not understand what he means by "ATTENUATION".
I thought ketosis on LCHF was from adipose tissue lipolysis?
The authors point to a recent study showing that
anti-catabolic effects of B-hydroxybutyrate (BHB)
were demonstrated in human skeletal muscle
under inflammatory insult
(in this case, provided by lipopolysaccharide, or LPS for short),
supporting the hypothesis that BHB can exert anti-catabolic effects
in inflammation-driven muscle atrophy.
I also remember reading years ago from the work of Steve Phinney and Jeff Volek
that the primary driver of muscle protein synthesis (MPS)
is the availability of essential amino acids (especially leucine)
and that in the keto-adapted state, blood levels of leucine increase.
Here, the keto-adapted state, which includes elevated levels of BHB, spares protein and preserves lean tissue. (For more on this, check out Phinney and Volek’s book,
The Art and Science of Low Carbohydrate Performance.)
So...I was wondering about all of this in the context of
fasting compared to chronic caloric restriction
and their effects on muscle loss/preservation.
Do higher BHB levels in water-only fasting prevent muscle loss
greater than hypocaloric (i.e., CR) states without high ketone (i.e., BHB/AcAc) levels?
I thought Phinney and Volek were concerned about nitrogen balance with fasting?
Also, it’s been observed that resistance training prevents most,
if not all in some cases, the muscle loss that comes with CR.
You may recall in one of my AMA’swhen I discussed my quarterly 7-day water-only fasts,
I’m amazed at the lack of muscle loss, provided I lift weights daily.
In fact, with many cycles of such fasts, I see the same results over and over,
suggesting that preservation of leucine alone is sufficient to maintain muscle mass.
Yes but how much weight did you lose.
7 days does not equal months of 10-30% weight loss.
That is where the difficulty lies. My BIA below demonstrates this with a 42 lb weight loss.
- Peter
On LCHF since 2011 I presume I have sufficient leucine intake. I frequently lifted weights during this period but I always lose muscle with significant weight loss. I don't know how Peter checks his fat percentage. I use a 4 electrode bioelectrical impedance scale.
From 6-23-15 to 3-23-17 I lost 42 lbs.
Muscle mass 46.1 lbs to 38.1 lbs
Fat mass 75.2 lbs to 49.5 lbs
