Ghrelin and leptin, putative controllers of human appetite, have no effect on human meal-to-meal appetite but respond to variations in energy availability. Nonhomeostatic characteristics of appetite and spontaneous activity stem from inhibition by leptin and ghrelin of brain reward circuit that is responsive to energy deficit, but refractory in obesity, and from the operation of a meal-timing circadian clock.
Ghrelin and leptin do not control human appetite and meal-to-meal eating but track changes in energy availability.
School of Kinesiology, The University of Michigan, Ann Arbor, MI
Address for correspondence: Katarina T. Borer, Ph.D., School of Kinesiology, The University of Michigan, 401 Washtenaw Ave., Ann Arbor, MI 48109 (E-mail: Katarina@umich.edu).
Accepted for publication: April 5, 2010.
Associate Editor: Barry Braun, Ph.D., FACSM