EFFECT OF ACUTE TRYPTOPHAN DEPLETION ON MOOD AND APPETITE IN HEALTHY FEMALE VOLUNTEERS

Twelve healthy female subjects received the following three drinks in a double-blind, semi-balanced, crossover design: (a) 50 g of amino aci ds without L-tryptophan (LTP); (b) 50 g of amino acid with LTP (balanc ed); (c) plain water. Compared to both the balanced amino acid mixture and plain water, the LTP drink significantly lowered plasma total and free tryptophan at 4.5 h. However, compared to the two control condit ions, there was no effect of the LTP drink on subjective ratings of mo od or hunger. Similarly, the LTP drink did not alter significantly eit her total calorie intake or the macronutrient content of a test meal 5 h after drink ingestion.