Changes in endogenous serum leptin levels expressed as leptin/BMI ratio after intravenous (i.v.) infusion of exogenous ghrelin (light blue) vs placebo (dark blue). The i.v. ghrelin/placebo infusion was a 10-min bolus that took place from –10 min to 0 min. Leptin time points are at baseline (−15 min), at the juice trial (+23 min), at the alcohol trial (+29 min) and post experiment (+48 min). There was a main effect for i.v. ghrelin administration on serum leptin levels (F1,38=8.249, P=0.007). Post hoc analysis revealed significant differences in leptin levels at the alcohol trial (t38=2.703, Pcorrected=0.031) that persisted at the end of the experiment (t38=2.720, Pcorrected=0.029). No significant differences in leptin levels (P=NS) were found during the juice trial (P=NS). BMI, body mass index; NS, not significant.