Schwartz A, et al. - Because chronic blood concentrations of testosterone are associated with food intake (FI), researchers analyzed the acute effects of testosterone on appetite, as well as the impact of protein and glucose consumption on testosterone response in this randomized, crossover study. Beverages containing either whey protein (1g/kg body weight), glucose (1g/kg body weight), or calorie-free control (C) were given to 23 males (12-18 years old). Plasma testosterone, luteinizing hormone (LH), GLP-1 (active), ghrelin (acylated), glucose, insulin, and subjective appetite were measured prior to and at 20, 35 and 65 minutes after drinking. In this population of adolescent males, protein or glucose ingestion resulted in acute reductions in both plasma testosterone and LH. No associations were found with appetite, ghrelin, or glycemic markers. Treatments did not affect the intake of food. The physiological significance of this response remains to be determined since no support has been found for the role of testosterone in acute dietary intake regulation.