This release via ScienceDaily summarizes the goals of present day calorie restriction research: "Organisms from yeast to rodents to humans all benefit from cutting calories. In less complex organisms, restricting calories can double or even triple lifespan. It's not yet clear just how much longer calorie restriction might help humans live, but those who practice the strict diet hope to survive past 100 years old. ... calorie restriction influences the same handful of molecular pathways related to aging in all the animals that have been studied. Aware of the profound influence of calorie restriction on animals, some people have cut their calorie intake by 25 percent or more in hopes of lengthening lifespan. [Researcher Luigi Fontana] is less interested in calorie restriction for longer life than in its ability to promote good health throughout life. ... Right now, the average lifespan in Western countries is about 80, but there are too many people who are only healthy until about age 50. We want to use the discoveries about calorie restriction and other related genetic or pharmacological interventions to close that 30-year gap between lifespan and 'healthspan.' However, by extending healthy lifespan, average lifespan also could increase up to 100 years of age."