Fatigue and leptin plots for participants with CFS. Left panes: Self-reported fatigue severity (solid blue line) "tracks" with serum leptin concentration (dotted green line) over the 25-day protocol in six patients with CFS (#'s 1, 2, 4, 5, 6, 9). Right panes: Scatter plots illustrate the strength of association between self-reported fatigue severity and serum leptin concentration. The data have been Z-score transformed to fit on the same scale. The mean AM and PM fatigue scores are displayed. Note for #4, the y-axis scale extends to 2.95 instead of 2.5 to accommodate a data point.