LH is decreased during fasting (A), primarily in males (B) and less (non-significant) in females (C) treated with placebo. Leptin replacement prevents the decrease of LH (A–D). FSH does not change independent of treatment (fed, fasting+placebo or fasting+leptin) (E–H). (Trt [Type of Treatment, i.e. Fed, fasting+placebo or fasting+leptin], Time [hours starting from 8 am on day 3 till 6 am on day 4]). P-values were calculated with two-way ANOVA and post-hoc Tukey’s test was used to compare the three types of treatment (Fed, Fa+Pl, Fa+Lep). One-way analysis of variance (Friedman test for paired and Kruskal-Wallis test for unpaired measurements) followed by post-hoc Dunn’s test was used to compare the area under the curves (AUCs) of the three treatment groups.