De kortslapers hadden de volgende ochtend veel hogere concentraties van het eetlustopwekkende ghreline in hun bloed, tot zo'n 15%meer. ###>Short sleepers had a much higher concentration, upt to 15%, of the appetite inducing ghreline in their blood. Furthermore, the researchers noticed that they had a less concentration of the appetite repressant leptin (15% less).