Safety, health improvement and well-being during a 4 to 21-day fasting period in an observational study including 1422 subjects Wilhelmi de Toledo, Françoise ; Grundler, Franziska ; Bergouignan, Audrey ; Drinda, Stefan ; Michalsen, Andreas Abstract Publication: PLoS ONE Pub Date: January 2019 DOI: 10.1371/journal.pone.0209353 Bibcode: 2019PLoSO..1409353W