Write 10 pages with APA style on Calorie Restriction. To further delay the process of aging and live longer, various health practices are carried out all over the world. Although there are many of these practices, only a few are systemized and supported by actual and genuine trials done by experts, which can stand scrutiny from any quarters. One of the main age delaying practices which have been studied extensively and intensively is calorie restriction. Calorie restriction (CR) is a lifestyle choice or a dietary schedule or experimental protocol in which the total intake of calories through food is restricted, with the restriction levels based on the subject’s previous calorie intake levels. This dietary regime is consciously or unconsciously practiced by various people and importantly implemented among other living species as test subjects in labs. The scientific studies to find the correlation between restricted diets and the ageing delay was started in the first half of the 19th century. It was in 1935, the effect of food restriction on aging or life span in laboratory rats was first described by Clive M. McCay and his colleagues at Cornell University. By placing rats on a very low-calorie diet, Clive M. McCay and his team extended the outer limit of the animals’ life span by 33 percent, from three years to four. “They subsequently found that rats on low-calorie diets stayed youthful longer and suffered fewer late-life diseases than did their normally fed counterparts.” (Weindurch 2006, p. 54). Since then, CR has been regarded as a key intervention that can slow aging in many living species particularly rodents. Another trial using monkeys, which has more common genetic content with humans, has been underway and it is also showing the correlation between CR and aging. The key thing about these trials is that CR does not mean&nbsp.malnourishment because they receive enough protein, fat, vitamins and minerals to maintain efficient operation of their tissues.&nbsp.