In a crossover design , @ healthy , nonobese adults ( @ men ) underwent a functional magnetic resonance imaging ( fMRI ) food-picture evaluation task after a @-h overnight fast ( Fasted-Saline ) or after eating breakfast @ min before scanning ( @ kcal , @ % protein , @ % fat , and @ % carbohydrate ) and receiving a saline ( Fed-Saline ) or acyl ghrelin ( Fed-Ghrelin ) subcutaneous injection before scanning .