Calorie Restriction - Research History

Research History

In 1934, Mary Crowell and Clive McCay of Cornell University observed that laboratory rats fed a severely reduced calorie diet while maintaining micronutrient levels resulted in life spans of up to twice as long as otherwise expected. These findings were explored in detail by a series of experiments with mice conducted by Roy Walford and his student Richard Weindruch. In 1986, Weindruch reported that restricting the calorie intake of laboratory mice proportionally increased their life span compared to a group of mice with a normal diet. The calorie-restricted mice also maintained youthful appearances and activity levels longer and showed delays in age-related diseases. The results of the many experiments by Walford and Weindruch were summarized in their book The Retardation of Aging and Disease by Dietary Restriction (1988) (ISBN 0-398-05496-7).

The findings have since been accepted and generalized to a range of other animals. Researchers are investigating the possibility of parallel physiological links in humans. In the meantime, many people have independently adopted the practice of calorie restriction in some form.

In 1989, scientists at University of Wisconsin started a study of 20 adult male rhesus monkeys; 9 of them were put on a normal diet and 11 were subjected to a 30% reduction in dietary intake. Results are being periodically published.

A study at UCSF called "CRONA" was started in December 2010, and studied 28 long-term CR practitioners over a few months. The study was completed on September 20, 2011. As of August 2012 the results had not yet been published.