Study reveals effects of prolonged fasting on human body

The study aimed to understand the comprehensive impacts of not eating on the body, as the exact biological outcomes of prolonged caloric restriction had not been thoroughly examined before. The researchers embarked on an analysis of systemic changes in multiple organs during prolonged food deprivation, revealing both the positive and negative health implications.

Healthy Volunteers Participate in Fasting Study

According to Chip, the study's authors recruited 12 healthy volunteers to partake in a seven-day fast. Throughout this period, the participants were allowed only to drink water, with no food intake. The researchers closely monitored the participants, tracking about 3,000 different changes in blood proteins each day.

The authors found that the volunteers' bodies switched from using glucose to burning stored fats for energy within the first few days of fasting. This switch resulted in an average weight loss of 5.7 kg (approximately 12.6 lbs) across the week, a loss that participants maintained even after resuming their normal diet.

Interestingly, the first few days saw no significant changes in blood protein levels. However, after the third day, researchers observed dramatic fluctuations in hundreds of compounds, many of which have significant health effects. By cross-referencing these fluctuations with genetic studies linking various proteins to diseases, the authors could predict the health outcomes of 212 changing blood plasma compounds during fasting.

Fasting Shows Mixed Health Outcomes

The study highlighted that avoiding food for more than three days reduced the plasma levels of the SWAP70 protein. Since low levels of this marker are linked to a decreased risk of rheumatoid arthritis (RA), the researchers suggest this could partly explain the relief RA patients might experience during prolonged fasting.

Conversely, the study also noted several adverse health effects associated with fasting. One such finding was an increase in clotting factor XI, indicating a potential rise in the risk of thrombosis events.

Claudia Langenberg, one of the research authors, emphasized, "For the first time, we can observe the molecular-level changes in the body due to prolonged fasting." She added that the study's results indicate health benefits beyond weight loss from not eating for extended periods, although these benefits only became evident after a total of three days of caloric restriction, later than previously believed.

Co-author Maik Pietzner summarized the findings by noting, "While prolonged fasting can aid in treating certain conditions, it is often not a viable option for individuals with existing health problems."