Fasting can reduce weight — but also hair growth

A colourful polarised light micrograph of cross section of human skin showing hair growing our of follicles

Human hairs sprout from follicles, which contain stem cells that are sensitive to dietary changes (artificially coloured).Credit: Dr Keith Wheeler/SPL

A popular weight-loss regimen stunts hair growth, data collected from mice and humans suggest1. The study’s findings show that intermittent fasting, which involves short bouts of food deprivation, triggers a stress response that can inhibit or even kill hair-follicle stem cells, which give rise to hair.