Procedure
Participants were required to fast, starting from 7 p.m. the day prior to the experiment, with the exception of water consumption. Upon arrival, a first blood sample was taken (10 ml) to assess baseline tryptophan levels. Participants were then administered the amino acid beverage (ADT or control). Following the oral consumption, participants were asked to wait in a designated waiting area for 4 h, given that the maximum depletion effect takes at least 4 h to develop (Williams et al. 