Posted on 01/09/2025 8:05:49 AM PST by Red Badger
A recent study highlights that significant health benefits and molecular adaptations from fasting are detectable after three days.
Recent findings show that prolonged fasting triggers significant and systematic changes across multiple organs in the body. These results highlight potential health benefits that extend beyond weight loss, but they also reveal that these impactful changes only begin to occur after three full days without food.
Health Benefits of Fasting Unveiled
A recent study published in Nature Metabolism sheds light on how the body responds to extended periods without food, offering valuable insights into the processes occurring during prolonged fasting.
Researchers from Queen Mary University of London’s Precision Healthcare University Research Institute (PHURI) and the Norwegian School of Sports Sciences explored the potential health benefits of fasting, focusing on its underlying molecular mechanisms. Their findings lay the groundwork for future research that could lead to therapeutic treatments, particularly for individuals who may benefit from fasting but are unable to participate in extended fasting or follow fasting-mimicking diets like ketogenic plans.
Historical Context and Modern Techniques
For thousands of years, humans have adapted to survive without food for extended durations. Today, fasting is widely practiced for both medical and cultural reasons, with goals ranging from improved health to weight loss. Historically, fasting has also been used to manage conditions such as epilepsy and rheumatoid arthritis, demonstrating its diverse applications across time and societies.
During fasting, the body changes its source and type of energy, switching from consumed calories to using its own fat stores. However, beyond this change in fuel sources, little is known about how the body responds to prolonged periods without food and any health impacts – beneficial or adverse – this may have. New techniques allowing researchers to measure thousands of proteins circulating in our blood provide the opportunity to systematically study molecular adaptions to fasting in humans in great detail.
Detailed Observations from a Controlled Study
Researchers followed 12 healthy volunteers taking part in a seven-day water-only fast. The volunteers were monitored closely on a daily basis to record changes in the levels of around 3,000 proteins in their blood before, during, and after the fast. By identifying which proteins are involved in the body’s response, the researchers could then predict potential health outcomes of prolonged fasting by integrating genetic information from large-scale studies.
As expected, the researchers observed the body switching energy sources – from glucose to fat stored in the body – within the first two or three days of fasting. The volunteers lost an average of 5.7 kg of both fat mass and lean mass. After three days of eating after fasting, the weight stayed off – the loss of lean was almost completely reversed, but the fat mass stayed off.
For the first time, the researchers observed the body undergoing distinct changes in protein levels after about three days of fasting – indicating a whole-body response to complete calorie restriction. Overall, one in three of the proteins measured changed significantly during fasting across all major organs. These changes were consistent across the volunteers, but there were signatures distinctive to fasting that went beyond weight loss, such as changes in proteins that make up the supportive structure for neurons in the brain.
Expert Insights on Fasting’s Effects
Claudia Langenberg, Director of Queen Mary’s Precision Health University Research Institute (PHURI), said:
“For the first time, we’re able to see what’s happening on a molecular level across the body when we fast. Fasting, when done safely, is an effective weight loss intervention. Popular diets that incorporate fasting – such as intermittent fasting – claim to have health benefits beyond weight loss. Our results provide evidence for the health benefits of fasting beyond weight loss, but these were only visible after three days of total caloric restriction – later than we previously thought.”
Maik Pietzner, Health Data Chair of PHURI and co-lead of the Computational Medicine Group at Berlin Institute of Health at Charité, said:
“Our findings have provided a basis for some age-old knowledge as to why fasting is used for certain conditions. While fasting may be beneficial for treating some conditions, often times, fasting won’t be an option to patients suffering from ill health. We hope that these findings can provide information about why fasting is beneficial in certain cases, which can then be used to develop treatments that patients are able to do.”
Reference:
“Systemic proteome adaptions to 7-day complete caloric restriction in humans”
by Maik Pietzner, Burulça Uluvar, Kristoffer J. Kolnes, Per B. Jeppesen, S. Victoria Frivold, Øyvind Skattebo, Egil I. Johansen, Bjørn S. Skålhegg, Jørgen F. P. Wojtaszewski, Anders J. Kolnes, Giles S. H. Yeo, Stephen O’Rahilly, Jørgen Jensen and Claudia Langenberg, 30 February 2024, Nature Metabolism.
DOI: 10.1038/s42255-024-01008-9
I’ve done 3 5-day water fasts the last 5 years and what’s really crazy is after day 2 your mind starts to clear and your tongue and sweat start to smell from all the impurities.
Ping
Was this study done with the expectation that Heels Up Harris would steal the election?
I have found fasting actually helps inflammation. Tendinitis in elbow and knees disappears
I would have to take a vacation to do a week long fast...because there would be too many safety risks at work and driving.
And since my company was bought up, they cut our PTO to 56 hours,just 7 days a year.
Boy do I ever want European vacation time and sick days.
Anyway, after three days of fasting you start burning ketones, and that causes your breath to smell.
ping
Me too but my blood tests was COMPLETELY CHANGED by 12 and rarely 18 hour fasts.
#### 3 days or 7!!!
I’ve done those folks...the others are lying...it’s a NIGHTMARE...and you gain it back in no time because you starved yourself.
Do 12..maybe 18
I’m all for scientific studies into health and diet. It would be great if we could take all the money we waste on “studying” climate change and the associated billion dollar marketing scams and the trillion dollar government policies regarding climate and put just 1% of that into real scientific studies. we’d probably solve most all the problems.
It’s not “the impurities,” that make your taste & sweat, etc., strange, it’s the acetone which is a breakdown product of fat metabolism. (Fat breaks down to acetoacetate, which loses CO2 spontaneously to make acetone.)
The farthest I’ve been able to go is 3 day fasts. The massive headaches always bring me out of it. I’ve tried electrolytes and all, but the headaches always make me break the fast. They are brutal.
Just literally broke a 3 day fast this morning due to high ketone levels.
The fasting coach I relied on has been saying much of this information for years.
Glad to see she is finally proven correct.
What’s wrong with high ketone levels?
Shortly after rolling blackouts are implemented across the country, food shortages will naturally follow.
This study teaches you to be happy about it.
The blackouts will be good for the planet, and the lack of food will be good for you.
Or put 1% of that into fire detection, prevention and fire fighting in LA. That would save tens of billions of lost property and lives.
What do you drink - just water? Any supplements?
Ketoacidosis if they get too high.
There is a therapeutic level you want to stay in during fasting. My coach says anything over 8 mmol/L on the ketomojo meter signals you to break your fast. You are getting into needing medical assistance.
Ketoacidosis if they get too high.
I thought that was only an issue for diabetics.
>The farthest I’ve been able to go is 3 day fasts. The massive headaches always bring me out of it.
Yeah, I’m type one so I have to be careful of my blood sugars as well, because your liver dumps all the sugar it has for two days and then runs out. That might be the headache reason.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.