Fig. 1.

Effect of tryptophan-enriched cereal intake on time in bed (a), assumed sleep (b), actual sleep time (c), sleep latency (d), sleep efficiency (e), immobile time (f), number of wake bouts (g), total activity score (h), and fragmentation index (i). Results are expressed as fold-increase over control levels (normalized and expressed as 1). Each value represents the mean ± SEM. Control: first week (22.5 mg of tryptophan was consumed in breakfast and dinner); treatment: second week (60 mg of tryptophan was ingested in breakfast and dinner); posttreatment week: habitual diet. *p<0.05 control vs. treatment; **p < 0.01 control vs. treatment; ***p < 0.001 control vs. treatment; +p < 0.05 treatment vs. posttreatment; Kruskal–Wallis test and Dunn's multiple comparison test (posttest) were performed. N = 35