What happens to the body when fasting for a long time?
How seven days of fasting transform the human body- Humans are made to live in times of lack of food. When food is not found, the body becomes dependent on the fat stored for energy rather than the glucose from eating.
How seven days of fasting transform the human body-
Thousands of years, people have fasted for religious, cultural, and health-related reasons. In recent years, this has also received more attention because studies have linked fasting and intermittent fasting to weight loss, improved metabolic health, and cellular repair processes.
Nevertheless, scientists have little understanding of how the body actually responds during the long fast.
To investigate this, researchers at Queen Mary University of London’s Precision Healthcare University Research Institute (PHURI) and the Norwegian School of Sports Sciences monitored 12 healthy volunteers during a seven-day water fast. Daily blood samples were taken before, during and after fasting.
Using advanced proteomics technology, the team tracked approximately 3,000 proteins circulating in the bloodstream. These proteins can give clues about what is happening in organs and tissue throughout the body.
The biggest changes started after the third day
As expected, within the first two to three days of fasting, the body rapidly began to burn fat by burning glucose.
Participants lost an average weight of 5.7 kg (about 12.5 lb), including both fat and lean tissue. When the participants resumed eating for three days, most of the lean tissue loss returned, while most remained fat loss.
But researchers discovered something even more surprising.
Large-scale changes in protein activity throughout the body did not begin immediately. Instead, large molecular changes became more noticeable after being without calories for about three days.
More than a third of the measured proteins changed significantly during fasting. Some of the biggest changes included proteins associated with the extracellular matrix. Which helps to provide structural support to tissues and organs, including neurons in the brain.
Change in protein levels among volunteers were largely similar, indicating that the body might exhibit a highly coordinated response during prolonged fasting.
Claudia Langenberg, director of the Queen Mary’s Precision Health University Research Institute (PHURI), said, “This is the first instance where we can observe the events occurring at the molecular level.”
“Fasting, when done in a safe manner, is an effective way to lose weight. Popular diets that include fasting, such as intermittent fasting, claim health benefits in addition to weight loss. Our results provide evidence of the health benefits of fasting in addition to weight loss. But they only appear after reducing the entire calorie for three days – later than we previously thought. “
Potential benefits besides weight loss
Researchers used genetic data from large human studies to examine. How changes in proteins observed during fasting could affect health over a longer period of time.
The results indicated possible links to improvements in many biological paths associated with disease risk and inflammation. Scientists also identified changes associated with proteins included in the brain support structure.
These results have raised interest in whether fasting can ever help researchers. To develop therapy for diseases associated with metabolism, aging, inflammation, or neurological health.
Since the 2024 study was published, interest in fasting research has been increasing. Recent reviews have linked intermittent fasting to improved insulin sensitivity, healthy lipid levels, and potential advantages for brain function and cardiovascular health.
Recent second studies on prolong fasting seven days of fasting transform the human body-
How seven days of fasting transform the human body. A recent second study on long-term fasting also found that during several days of fasting. The body moves to a deep ketogenic state, significantly changing the way sales fuel is used.
Scientists also found potential risks
Although fasting may have beneficial biological effects, researchers warn that fasting is not risk free for long periods of time.
A later proteomics study, in which fasting was done by drinking only water for a long time. Found evidence of changes in pathways associated with inflammation, platelet activation, and blood clotting during prolonged fasting. Researchers said these effects may show temporary stress response, but they also emphasized the long-term health impact of too much fasting, and the need for research.
Experts have also warned that prolonged fasting may increase the risk of complications in people with dehydration, electrolyte imbalance, dizziness, muscle loss, and pre-existing health problems.
Because of these risks, fasting should not be done for long periods without medical guidance, especially those with diabetes, eating disorder, cardiovascular disease or other chronic diseases.
Why are scientists excited about these results
Researchers say that one of the most important discoveries was the timing of the body’s response.
Many popular methods of fasting focus on fasting for short periods of time. But this study suggests that some of the larger molecular changes in the body may require a complete calorie reduction for several days.
Co-lead Mike Petzner of the Computational Medicine Group at PHURI’s Health Data Chair and Berlin Institute of Health in Charité said, “Our Findings has given a basis for some old information on why fasting is used for certain conditions goes.”
“Although fasting may be beneficial for the treatment of certain conditions, fasting is not an option for patients struggling with poor health. We hope that these findings can provide information on why fasting is beneficial in certain cases, which can then be used to develop treatments that patients can use. “
Story Source:
Study by Queen Mary University of London.
Journal Reference: 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, Claudia Langenberg. Systemic proteome adaptions to 7-day complete caloric restriction in humans. Nature Metabolism, 2024; 6 (4): 764 DOI: 10.1038/s42255-024-01008-9