Fasting-Induced FOXO4 Blunts Human CD4+ T Helper Cell Responsiveness

This fasting and refeeding pilot study was registered in ClinicalTrials.gov with the registration number NCT02719899 and approved by the National Heart and Lung Institute IRB. Overall design: Subjects were screened in the ambulatory clinic and signed informed consent for the protocol prior to undertaking the study (Visit 1). Subjects initiated the study after an overnight fast with blood draw for the baseline immune response (Visit 2). After overnight fasting the study subjects consumed a fixed 500 calorie meal before 8am in the morning and fasted for 24 hours except for unrestricted water intake. Following a 24-hr. fasting blood draw (Fasting-Visit 3), the subjects ate another 500 calorie meal with post-prandial blood draws 3 hours later (Refed-Visit 3).