Administration of Theanine,a Unique Amino Acid in Tea Leaves,Changed Feeding-Relating Components in Serum and Feeding Behavior in Rats

We identified an effect of γ-glutamylethylamide (theanine) on feeding in a rat study. Oral theanine suppressed the food intake of rats. The serum glucose level did not differ from the control, but the insulin concentration was reduced and the corticosterone concentration was increased by theanine. We suggest that the effect of theanine on feeding involved hormones.