A complete weeklong fast triggers large-scale biological changes across all human internal organs, with the most pronounced processes beginning only on the third day of fasting, reports infohub.kz.
According to ScienceDaily, the study was conducted by researchers from Queen Mary University of London and the Norwegian School of Sport Sciences. It involved 12 volunteers who drank only water for seven days. The authors tracked the levels of about 3,000 proteins in the participants' blood daily to examine in detail how organic systems respond to a complete cutoff of calories.
In the first two to three days, the body switches from using glucose to burning fat stores. However, large-scale changes in the proteome—the entire set of proteins—appear only after 72 hours of fasting. About one-third of the studied proteins significantly change their concentration, exerting systemic effects on all major organs, including support for neural connections in the brain.
During the experiment, participants lost an average of 5.7 kilograms. Yet three days after returning to normal eating, muscle and water mass fully recovered, while the fat component of the retained weight remained reduced.
The researchers hope the findings will enable the development of drugs that mimic the beneficial effects of fasting without the need to completely give up food.