The aim of this study was to examine the effect of acute alcohol intake on circulating concentrations of insulin, C-peptide, insulin-like growth factor (IGF) binding protein-1 (IGFBP-1), and plasma glucose levels. We measured these parameters for 12 hours after administration of 0, 0.5, or 1.0 g ethanol/kg body weight to nine healthy volunteers between 7:00 and 7:45 PM according to a randomized, double-blind, crossover design. Following a snack at 9:00 PM, plasma insulin (P