December 2021 PMID 34668663

Is muscle and protein loss relevant in long-term fasting in healthy men? A prospective trial on physiological adaptations.

Claire Laurens, Franziska Grundler, Anthony Damiot, Isabelle Chery, Anne-Laure Le Maho, Alexandre Zahariev, Yvon Le Maho, Audrey Bergouignan, Guillemette Gauquelin-Koch, Chantal Simon, Stéphane Blanc, Françoise Wilhelmi de Toledo

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Mentions

120

Peak: 26 in Oct 2021

across 5 sources since Oct 2021

Extended reach

1,345,218

potential audience

Total likes

3,525

Video views

128,241

Mentions per month

Oct 2021 – Nov 2025

Where it's discussed

X / Twitter92 posts
News15 articles
YouTube9 videos
Reddit3 posts
Bluesky1 posts

AI synopsis

What people are saying

Many discussions highlight the reduced muscle loss during fasting, with users referencing examples like the study’s assertion that most lean mass loss occurs from non-muscle tissues rather than muscle itself. Phrases such as 'hardly any loss of muscle' and 'not negatively impact muscle function' contribute to a tone of certainty and validation regarding the findings, enhancing the overall sentiment of agreement and interest.

AgreementModerate agreement

Overall, posts generally affirm the study's findings, with many noting that muscle loss is minimal during fasting.

InterestHigh interest

Contributors express high curiosity regarding the implications of fasting, especially concerning muscle preservation.

EngagementHigh engagement

Numerous posts dive into details about the study's findings and share anecdotal evidence or references to related research, demonstrating a strong engagement level.

ImpactModerate impact

While many acknowledge the research's significance, some express skepticism about its wider implications, hence keeping the impact score moderate.

Abstract in brief

Fasting can be an effective strategy for weight loss and improving metabolic health, as shown in a study where healthy men fasted for 10 days while engaging in low-intensity physical activity.
The participants lost about 7% of their body weight, primarily from lean soft tissues and fat, while also experiencing a significant decrease in basal metabolic rate.
Muscle strength in weight-bearing activities improved or was maintained despite muscle mass loss, and various health markers like blood sugar and lipids showed favorable changes during the fasting period.

Read the full abstract

All mentions

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しー

@atticisliked · X

https://t.co/96trIk6XDq 平行で起こるけど脂肪:40%:筋肉8.4%で比率的に差があるっぽい https://t.co/LwulOxkzcK

Sep 24, 2025 · 863 followers View post →

David

@primarycarepac.bsky.social · Bluesky

Would you do a 10-day fast if strength was preserved? Or is muscle loss a dealbreaker?

Mar 2, 2025 · 1 share View post →

David_Propst_PA-C

@PrimaryCarePAC · X

Would you do a 10-day fast if strength was preserved? Or is muscle loss a dealbreaker?

Mar 2, 2025 · 1 like · 3,332 followers View post →

Ketogenic European

@Ketogenic_EU · X

@ketodontist @DikemanDave Is there? Buchinger fasting is well known in Germany, although it isn't 0kcal, it's 250 (soup, I think) There's also animal evidence that organs shrink, everything but brain and sex organs I think BMI and dose matters https://t.co/eYVaye0Rgw https://t.co/HdMaz4m1Az

Dec 29, 2024 · 1,028 followers View post →

Claus Carlsen

@ClausCarlsen1 · X

Fasting (in this case wet) combined with physical activity does not negatively impact muscle function. Almost all weight lost is water, glycogen, fat and lean tissue other than muscle! https://t.co/LfNoDdSTSb

Oct 11, 2024 · 8 likes · 15,758 followers View post →

Claus Carlsen

@ClausCarlsen1 · X

@CaryKelly11 Normal wet fasting causes hardly any loss of muscle fibre! Most of the lean weight loss is water, glycogen, organ and tissue. https://t.co/LfNoDdTrHJ

Oct 7, 2024 · 5 likes · 15,758 followers View post →

Claus Carlsen

@ClausCarlsen1 · X

@JentacularXertz @justask66054535 @BenBikmanPhD @KetoCarnivore The partner was Charité University Hospital Berlin which is associated with Humboldt university Berlin as well as Freie Universität Berlin. https://t.co/LfNoDdTrHJ

Oct 7, 2024 · 3 likes · 15,758 followers View post →

Me-G

@HIT_Greg · X

@netineti_expand @SirBarefoot https://t.co/t4P7OFLKua

May 28, 2024 · 132 followers View post →

Daniel 21e15

@Daniel21e15 · X

@DzambhalaHODL That is true in the presence of elevated blood insulin levels. After ketogenesis kicks in (day 2-ish), the muscle wasting stops and general physical performance increases. Otherwise, humans would have been extinct a long time ago. https://t.co/rPUN2skbjA

Apr 14, 2024 · 2,936 followers View post →

Fervent Flâneur

@ferventfinance · X

@ppearlman @JeffMacke @PeterAttiaMD He was doing quarterly week-long fasts, I believe. Intuitively, it makes sense; here is a white paper supporting that. https://t.co/i41DygmUOg

Jan 19, 2024 · 1 like · 7,245 followers View post →

Angel ⚡

@Angeltamin · X

@cIeputamaniaca Não é uma coisa boa pra profissionais dizerem pras pessoas que podem ficar 10 dias sem comer sem tantos malefícios, mas tem estudos que levam ao extremo pessoas saudáveis e demonstraram 0 catabolismo, da uma lida, é bem interessante https://t.co/t3Er7iBAPh

Jan 17, 2024 · 676 followers View post →

Angel ⚡

@Angeltamin · X

@cIeputamaniaca Sim, ainda mais se a pessoa não tiver gordura pra perder, o mais atual que tem sobre jejum é: "Estudo revela que jejum de 10 dias resulta em perda de peso com preservação muscular. A perda de gordura representa 40%, enquanto manteve a massa https://t.co/t3Er7iBAPh

Jan 17, 2024 · 1 like · 676 followers View post →

Claus Carlsen

@ClausCarlsen1 · X

@keto3000 @RauchStopp_AT Losing muscle is not really an issue when fasting a few days. According to research by Buchinger Wilhelmi most lean mass loss in fasts up to 10 days is from other lean tissue than muscles. Here's a link to the study: https://t.co/hj44M2RUyP

Jan 2, 2024 · 4 likes · 15,758 followers View post →

Claus Carlsen

@ClausCarlsen1 · X

@Salud_Sapiens Almost all lean tissue loss is not from muscles but from your inner organs! https://t.co/hj44M2RUyP

Dec 21, 2023 · 1 like · 15,758 followers View post →

Anssi H. Manninen | Mass Balance Man

@KingManninen · X

Is muscle and protein loss relevant in long‐term fasting in healthy men? A prospective trial on physiological adaptations - Laurens - 2021 - Journal of Cachexia, Sarcopenia and Muscle - Wiley Online Library https://t.co/xDj2HJ6mLR

Dec 20, 2023 · 2 likes · 1,056 followers View post →

Bitcoinobserver

@BitcoinObserv · X

RT @ClausCarlsen1: Fasting - hardly any loss of muscle: https://t.co/hj44M2RUyP

Dec 20, 2023 · 2 shares · 119 followers View post →

Pro-American

@bryanswiley · X

RT @ClausCarlsen1: Fasting - hardly any loss of muscle: https://t.co/hj44M2RUyP

Dec 20, 2023 · 2 shares · 605 followers View post →

Claus Carlsen

@ClausCarlsen1 · X

Fasting - hardly any loss of muscle: https://t.co/hj44M2RUyP

Dec 20, 2023 · 22 likes · 2 shares · 15,758 followers View post →

H.E.R.O.

@HealingFaster · X

@ndev_support Muscle loss is minimal even in a 10 day fast: https://t.co/qm7Wci1LtI

Dec 20, 2023 · 2 likes · 1,487 followers View post →

Claus Carlsen

@ClausCarlsen1 · X

@JacquesSycamore @Go_DoctorGranny Multi day fasts cause weight loss - of which 40% fat, 35% Extra cellular water & water bound to glycogen, 25% protein mainly from liver, spleen, & kidneys only minimal from muscles! A study from Buchinger Wilhelmi: https://t.co/hj44M2RUyP

Dec 4, 2023 · 15,758 followers View post →

Robin Mesnage

@Robin_Mesnage · X

@MennoHenselmans Good review but not so recent studies are lacking. Muscle proteins are quite preserved by protein sparing mechanisms, function is fully preserved, and what is lost is quickly recovered by a rapid regeneration after fasting https://t.co/tAGjqMWIPH

Sep 30, 2023 · 1,463 followers View post →

Claus Carlsen

@ClausCarlsen1 · X

@exfatloss @sudas1891 weight loss when fasting - 40% fat, 35% Extra cellular water & water bound to glycogen, 25% protein mainly from liver, spleen, & kidneys only minimal from muscles! https://t.co/MaPXcywmmq https://t.co/xfuDj6Cjpe

Sep 15, 2023 · 2 likes · 15,758 followers View post →

大道无形

@hubin369 · X

RT @ClausCarlsen1: The study on fasting: https://t.co/hj44M2RmJh

Sep 7, 2023 · 1 share · 810 followers View post →

Dr. Syed Haider:

@DrSyedHaider · X

10 day fast in men doesn’t lead to muscle loss. https://t.co/eOL9EioFh7

Sep 6, 2023 · 3 likes · 176,911 followers View post →

Keto Nordic

@KetoNordic · X

RT @ClausCarlsen1: @holmanm Just read this research paper this morning which confirms so many benefits of fasting we have all felt Marion.…

Sep 6, 2023 · 1 share · 68 followers View post →

Claus Carlsen

@ClausCarlsen1 · X

The study on fasting: https://t.co/hj44M2RmJh

Sep 6, 2023 · 16 likes · 1 share · 15,758 followers View post →

Claus Carlsen

@ClausCarlsen1 · X

@holmanm Just read this research paper this morning which confirms so many benefits of fasting we have all felt Marion. It's great

Sep 6, 2023 · 5 likes · 1 share · 15,758 followers View post →

Steven M. Belknap, MD PGY43

@StevenMBelknap · X

@richcollins Not so much. Lean Soft Tissue Mass ≠ Muscle Mass. Loss of muscle glycogen ≠ Muscle Weakness. Despite what vendor of GymBro Magic Muscle Brew® says, healthy humans show no decrease in muscle function over the course of 10-day fast. Read all about it: https://t.co/IF9ZjVyRnQ https://t.co/Tmj462ruI9

Aug 3, 2023 · 1 like · 2,197 followers View post →

britton winterrose

@bwinterrose · X

@Empathy2000 Yeah what's interesting is we see similar protein loss in long fasting, but my understanding is that with long fasting it decreases as the body shifts to ketosis. https://t.co/P638GxY2fL

May 26, 2023 · 1 like · 11,349 followers View post →

Josef | Fit Dad

@FitDadJosef · X

@TomHasssan1 1. I don't know & don't care. Weight loss was not my motivation. 2. Probably not much. I do 100 push ups/day challenge daily (as you could see if you scroll my account a bit). My performance improved during the fast. See also: https://t.co/DDZ4T5eczE

May 24, 2023 · 2,449 followers View post →

Steven M. Belknap, MD PGY43

@StevenMBelknap · X

@MatthewJDalby @TamarHaspel During prolonged fasting, muscle strength is preserved in those obese patients who have access to fat stores, perhaps because insulin is low. https://t.co/3brUGNZyW6

Apr 26, 2023 · 2,197 followers View post →

dr cavey phd ⏳

@cavemanloverboy · X

@samvwaal @robmcandrewjr @salkinstitute https://t.co/XtkkEHy1lN

Apr 1, 2023 · 2 likes · 5,831 followers View post →

MGF

@ForgachMarie · X

@mikalpin @DocLucas4 @tyler64000 https://t.co/vBDJhIYZjR

Mar 3, 2023 · 489 followers View post →

Joker

@BachelorJoker · X

@roddebod17xxx @FitFounder Not with protein intake (Keto) and working out. https://t.co/ELQRti2GOk

Feb 25, 2023 · 24,282 followers View post →

Dr. Seltsam

@drseltsam · X

@quarkswdr Woher kommt Eure Info, dass man beim Fasten Proteine verbrennt? Studien zeigen klar, dass das nicht so ist. Z.B. https://t.co/JAOIe5iCMp Macht auch keinen Sinn, dass der Körper die Muskeln kaputt macht, die er fürs Beschaffen der Nahrung braucht. Erst wenn kein Fett mehr da ist

Feb 22, 2023 · 178 followers View post →

Eric Booth

@Eric_C_Booth · X

1.15 Fact 21 - As a result of fasting, the ribonuclease molecules have more time to destroy the viral RNA before it replicates. https://t.co/PnqlXS4kF9 https://t.co/4F4Mwrsx1n

Feb 16, 2023 · 1 like · 545 followers View post →

GoldenSilver

@SilverMindset · X

@KristerKauppi @Boldizar @maml_UWMadison @mkaeberlein Fasting Without Losing Muscle (5 DAY FAST RESULTS) https://t.co/DAtVMiGQli "Fasting combined with physical activity does not negatively impact muscle function" https://t.co/BY6UOYNmwD @drjasonfung https://t.co/Q7oR6gQcoq @PeterAttiaMD https://t.co/lwgkU7paFS

Dec 16, 2022 · 2,893 followers View post →

gravis

@gravis821 · X

@najib__rahal @Fathers_Club_ https://t.co/xpyDLeYjV1 https://t.co/QtKdSmphTB https://t.co/KYOLIBHNi6 https://t.co/nZC3LUIZJL https://t.co/GC4f2qWMYJ

Oct 2, 2022 · 1 like · 264 followers View post →

مقاومة الانسولين insulin resistance

@insulin_resista · X

@palmsea_17 الصيام من 12 الى 18 ساعة لايكاد يذكر فقد العضلات فيه،سيما اذا اخذت كفايتك من البروتين،اما اذا كنت تمارس رياضه مقاومة فلا تقلق نهائياً من فقد العضلات ووجدت دراسة انه في الايام الاولى يحدث فقد بسيط في العضلات ولكن مع الاستمرار ينتج الجسم كيتونات تمده بالطاقة https://t.co/oodkXArzgX

Sep 15, 2022 · 2 likes · 30,711 followers View post →

Robin Mesnage

@Robin_Mesnage · X

That's why our studies on long-term #fasting at the Buchinger Wilhelmi clinics are far-reaching, such as our most recent study on the preservation of muscle mass in collaboration with the French National Centre for Space Studies (https://t.co/cAigNoSAGC).

Aug 30, 2022 · 1,463 followers View post →

Shimon Shvartsbroit

@Shvartsbroit · X

@PazWeiner @Orio215 @erlichya אגב, חיפוש קצר באינטרנט של is fasting muscle sparing מראה שאין סכנה למסת שריר בצום. לא התעמקתי אבל אולי יעניין אותך https://t.co/NORkJWDxv5 https://t.co/pQVSOpuubH ויש עוד מחקרים. https://t.co/W5UEPnKeYN

Jul 29, 2022 · 1 like · 2,693 followers View post →

Shimon Shvartsbroit

@Shvartsbroit · X

@BUSH_FI https://t.co/JeZkAjHlHo. זה חיפוש ראשון באינטרנט Conclusions: A 10 day fast appears safe in healthy humans. Protein loss occurs in early fast but decreases as ketogenesis increases. Fasting combined with physical activity does not negatively impact muscle function

Jul 29, 2022 · 2,693 followers View post →

Steven M. Belknap, MD PGY43

@StevenMBelknap · X

@AJA_Cortes Nonsense. If there is adequate fat mass, a 10 day fast is safe. Protein loss occurs in early fast but decreases as ketogenesis increases. Fasting plus physical activity does not negatively impact muscle function. https://t.co/3brUGNZyW6

Jul 26, 2022 · 2,197 followers View post →

金森重樹@ダイエットonlineサロン

@ShigekiKanamori · X

@playinquiry グリコーゲン枯渇、水分減少、初日のタンパク質分解が減少の理由だとおもいますが体重はたいして変わりません（水とサプリは飲んでます）減量のためではなく炎症抑制とか長寿なので肥満の場合とは違いますが肥満だと変わるとおもいます https://t.co/GhgTgW7YKf

Jul 20, 2022 · 2 likes · 125,320 followers View post →

Steven M. Belknap, MD PGY43

@StevenMBelknap · X

@BubblesStud21 @SkinMD13 @kevinnbass “A 10 day fast appears safe in healthy humans. Protein loss occurs in early fast but decreases as ketogenesis increases. Fasting combined with physical activity does not negatively impact muscle function.” https://t.co/3brUGNZyW6

May 2, 2022 · 2,197 followers View post →

Robin Mesnage

@Robin_Mesnage · X

@racsonamas1 @CharlesMBrenner There are urban legends. Physiological adaptations during fasting are not well known. A lot of work has been started recently at Buchinger Wilhelmi, like this recent study showing the activation of protein sparing mechanisms during long-term fasting https://t.co/cAigNoSAGC

Apr 23, 2022 · 1 like · 1,463 followers View post →

Nick

@upRootNutrition · X

@rf121rf @KenDBerryMD Are AAs taken from muscle at all? If yes, then my position just goes through, bud.

Apr 23, 2022 · 3 likes · 9,511 followers View post →

Steven M. Belknap, MD PGY43

@StevenMBelknap · X

@CharlesMBrenner If there are adequate fat stores, a 10 day fast doesn’t worsen muscle function. There is some loss of lean tissue but more fat is lost. https://t.co/3brUGNZyW6

Apr 22, 2022 · 6 likes · 2,197 followers View post →

Stephen Brown, Mr. Man

@sbrown64 · X

@winfinancial @BiggestComeback No problem with protein & fiber. Also, here's some articles about fasting & muscle loss - https://t.co/7DoObU7MQR & https://t.co/B4HCV8Swsd

Mar 2, 2022 · 180 followers View post →

Jose Amoros

@joseluisamoros · X

Is muscle and protein loss relevant in long‐term fasting in healthy men https://t.co/xXeKTLOyol

Dec 22, 2021 · 341 followers View post →

Tim Noakes

@ProfTimNoakes · X

RT @NutritionNetwrk: In a recent study on muscle & protein loss being relevant in long-term fasting in healthy men, findings have shown tha…

Dec 22, 2021 · 2 shares · 158,499 followers View post →

Nutrition Network

@NutritionNetwrk · X

RT @NutritionNetwrk: In a recent study on muscle & protein loss being relevant in long-term fasting in healthy men, findings have shown tha…

Dec 22, 2021 · 2 shares · 7,191 followers View post →

Nutrition Network

@NutritionNetwrk · X

In a recent study on muscle & protein loss being relevant in long-term fasting in healthy men, findings have shown that a 10day fast appears safe in healthy humans https://t.co/xvhARwjYM2 Enrol in the @NutritionNetwrk LCHF courses here https://t.co/XHomnxbQR8 https://t.co/heOvxiW4E4

Dec 22, 2021 · 12 likes · 2 shares · 7,191 followers View post →

Alex

@AlexViKu · X

RT @DrMyohead: Is muscle and protein loss relevant in long-term fasting in healthy men? A prospective trial on physiological adaptations I…

Dec 9, 2021 · 4 shares · 97 followers View post →

NaO

@spikeoutOXY · X

RT @DrMyohead: Is muscle and protein loss relevant in long-term fasting in healthy men? A prospective trial on physiological adaptations I…

Dec 8, 2021 · 4 shares · 153 followers View post →

James McKendry, Ph.D.

@james_mckendry · X

RT @DrMyohead: Is muscle and protein loss relevant in long-term fasting in healthy men? A prospective trial on physiological adaptations I…

Dec 8, 2021 · 4 shares · 1,314 followers View post →

Dr. Myohead

@DrMyohead · X

Dec 8, 2021 · 19 likes · 4 shares · 2,645 followers View post →

Zaahid

@Nutell5sandwich · X

RT @B_Holmer: Interesting study on changes in body comp, strength, BMR, and metabolism during a 10-day fast. Is muscle and protein loss re…

Dec 7, 2021 · 2 shares · 49 followers View post →

Loyd Christensen

@loiteringloyd · X

RT @B_Holmer: Interesting study on changes in body comp, strength, BMR, and metabolism during a 10-day fast. Is muscle and protein loss re…

Dec 7, 2021 · 2 shares · 158 followers View post →

Brady Holmer

@B_Holmer · X

Dec 7, 2021 · 17 likes · 2 shares · 26,346 followers View post →

Agingdoc

@agingdoc1 · X

Is muscle and protein loss relevant in long-term fasting in healthy men? A prospective trial on physiological adaptations https://t.co/63T86PddTh

Nov 23, 2021 · 3 likes · 41,699 followers View post →

Ivanna Coffee

@IvannaCoffee · X