Underlying the importance of research on the biology of aging is the fact that many nations face the demographic reality of a rapidly aging populace and the looming healthcare challenges that it brings. This reality is a result of aging itself being the most significant risk factor for a range of the most prevalent diseases, including many cancers, cardiovascular disease, and diabetes. Accordingly, interventions are sorely needed that would be able to delay or prevent diseases and disorders associated with the aging process and thereby increase the period of time that aging individuals are in good health (the health-span). Caloric restriction (CR) has emerged as a model of major interest as it is widely agreed that CR is the most potent environmental intervention that delays the onset of aging and extends life span in diverse experimental organisms. A better understanding of the mechanisms by which CR delays aging will reveal new insights into the aging process and the underlying causes of disease vulnerability with age. These novel insights will allow the development of novel treatments and preventive measures for age-associated diseases and disorders. Am. J. Hum. Biol. 2012. © 2012 Wiley Periodicals, Inc.