Become a member of BioTechniques (it's free!) and receive the latest news in the life sciences and member-exclusives.

What happens to your body at a molecular level while fasting?

Written by Jade Parker (Contributing Editor)

Through in-depth characterization of approximately 3000 plasma proteins, researchers have identified systemic adaptations that take place across multiple organs when fasting.

Fasting has long held great significance in religious practices and more recently it has become a popular weight-loss strategy. However, apart from knowing that the body switches its fuel source from glucose to energy stores in adipose tissue, very little is known about what changes the body undergoes during periods of caloric restriction.

“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,” explained study author Claudia Langenberg (Queen Mary University of London, UK and Charité – Universitätsmedizin Berlin, Germany).

In this study, a multi-institutional group of researchers performed an in-depth protein-focused analysis of 12 individuals who undertook a 7-day water-only fast. By measuring the levels of approximately 3000 proteins before, during and after fasting the team identified nine distinct proteomic response profiles that appeared after 3 days of caloric restriction.


No food for 2 days keeps the doctor away: the impact of fasting on infection

Fasting in mice impacts the strength of a gastrointestinal infection and the subsequent damage caused, reveals a new study highlighting how the microbiome links fasting and infection. 


“Our results provide evidence for the health benefits of fasting beyond weight loss, but these were only visible after 3 days of total caloric restriction – later than we previously thought,” Langenberg commented.

The team observed that the multi-organ response was consistent among study participants and that more than 1000 proteins exhibited a significant response to the restricted diet. An average weight loss of 5.7 kg was recorded among study participants.

By combining proteomics and genomics, the team investigated the potential health consequences and uncovered some potential benefits for conditions such as rheumatoid arthritis and heart disease. Additionally, the team observed that fasting triggered marked alterations in a brain-specific protein termed tenascin-R.

The team hopes that this increased understanding of the proteomic changes taking place during prolonged fasting can help unearth why it is beneficial for certain individuals to fast as well as reveal new treatment options for those patients who are not able to.