Loss of Lean Muscle During Fasting, Old Study

science
fasting
#1

I have read Dr. Fung extensively, listened to the Podcasts by the 2Keto and have done some 5 day fasts. However, I was concerned when I saw this study mentioned by someone on Reddit who I think was quoting one of Atkin’s books. https://www.reddit.com/r/keto/comments/kksaq/one_of_the_strongest_arguments_for_keto_fat_lost/

“Now let’s look at some other research that supports the fat-burning theory, this time from the Oakland Naval Hospital. Impressed with the Kekwick and Pawan success, Frederick Benoit and his associates decided to compare a 1,000calorie, 10-grams-of-carbohydrate, high-fat diet with fasting (the same principle that Kekwick and Pawan found most effective), using seven men weighing between 230 and 290 pounds. They used state-of-the-art body composition technology. After ten days, the fasting subjects lost 21 pounds on average, but most of that was lean body weight; only 7.5 pounds was body fat. However, on the controlled carbohydrate regimen over the same period of time, 14 of the 14.5 pounds lost was body fat. Think of it. By eating foods low in carbohydrate and high in dietary fat, subjects burned their fat stores almost twice as fast as when they ate nothing at all!
Benoit’s other exciting discovery was that on a fat-burning regimen, subjects maintained their potassium levels, while subjects who fasted experienced major potassium losses. (Potassium depletion can cause heart arrhythmia, which, in severe cases, can be fatal.”

I would imagine some of the 21 lbs was water weight but I am still concerned about lean muscle preservation. Could it be autophagy? That they are eliminating old protein, excess skin? My theories and I am not a scientist.

Here is the study if you are a member of the American College of Physicians. I would love to see the entire study but am not willing to pay. It seems it uses potassium loss as a proxy for muscle loss but that is only a guess since I can only access a tiny portion.
http://annals.org/aim/article/680246/changes-body-composition-during-weight-reduction-obesity-balance-studies-comparing

Does Fasting Cause Muscle Loss?
(LJ) #2

Most recent studies show the opposite of this. My guess is that their “modern” technology for LBM was not valid.

Also, we drop glycogen from central organ muscle in addition to liver stores. I can’t access the full study (at home at the moment) but I would wager it’s an error of measurement.

#3

Thank you at @Eccemus

If you have access to the real study it would be great if you could provide details. The last thing I want is to become more flabby!

(Tom Seest) #4

I don’t have access to the study.

However, in my own N=1, I gained 1.4 kg of Lean Body Mass while losing 5.8 kg of body fat during an 11 day water fast as confirmed by a DEXA before and after.

Of course, Lean Body Mass could mean anything.

#5

Thank you.

How much and what type of exercise did you do at that time?

I have not been exercising much at all and I wonder whether that matters

(Tom Seest) #6

I curled weight with my arms 5 minutes per day. I also rode my bicycle during that time, at a lower than normal pace. Nothing dramatic.

I suspect the increase in Human Growth Hormone had something to do with the increase, and not the protein I wasn’t consuming…

#7

Makes sense.

Agree about what is lean tissue being undefined. I read a site recently that was higher carb that advised members to do LC and fasting for the last few pounds to avoid excess skin! Not sure where I saw this.

I enjoy biking but am always afraid to ride while fasted. I know it is silly but I worry about my balance and reaction time. I ride in suburban traffic and there are times when you have to be alert, it is mental

(Tom Seest) #8

I never ride when I don’t feel alert. It’s just to dangerous out there.

(Traci ) #9

I know this is an older post but please link the recent studies that show the opposite.