As early as the 16th century, humans have been fascinated with the idea of "the fountain of youth." Since then, people have made great attempts at lengthening their life span, all the while hoping to maintain optimal health as long as they can. Recent studies have suggested calorie restriction (CR) as a possible way to delay or prevent the onset of many aging-related conditions with increased longevity and health span. CR is defined as a 10-40% reduction in intake of a nutrient-rich diet....