Study reveals biological shifts during three-day fasting period

A study conducted by Queen Mary University of London and the Norwegian School of Sport Sciences has revealed significant biological shifts that occur during extended fasting. By monitoring 12 healthy volunteers during a seven-day water-only fast, researchers analyzed approximately 3,000 proteins to understand how the body responds to energy deprivation.

During the first two to three days, the body undergoes a metabolic shift, reducing its reliance on glucose and increasing the use of stored fat for energy. While participants lost an average of 5.7 kg over the week, this weight loss included both fat and lean mass. Notably, most lean mass was recovered upon resuming food intake, whereas fat loss was sustained.

Researchers identified the third day as a critical biological threshold. Beyond this point, significant changes were observed in proteins across multiple organ systems, not just in the liver or adipose tissue. Approximately one-third of the measured proteins showed substantial changes, indicating a widespread systemic response to the lack of food.