Effects of gamma-hydroxybutyrate administration on respiratory exchange ratio (RER). Data are presented as percentage of the mean of the first 4h of the baseline. Two-way repeated-measures analysis of variance for factors “treatment,” “time-point,” and their interaction, followed by Holm-Sidak post hoc test, P < 0.001 for “treatment” and “time-point”; black lines connect significant different time-points between treated and control mice, P < 0.05).