GFRAL and Anorexia: In accordance with our previous work (Ost et al, 2020), we here demonstrate an involvement of the GDF15-GFRAL axis in the induction of metabolic flexibility, which is likely because of the induction of daytime-restricted anorexia, similar to the beneficial metabolic health effects of time-restricted feeding in preclinical models and humans (Regmi & Heilbronn, 2020).