The CALERIE study is being carried out at the Pennington Biomedical Research Center (Baton Rouge, Louisiana), the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University (Boston, Massachusetts) and the Washington University School of Medicine (St. Louis, Missouri).
[1] It is hoped that caloric restriction reduces the incidence of cardiovascular disease and cancer and leads to a longer life, as has been demonstrated previously in numerous animal studies.
The subjects are then taught a diet of low-energy density foods, such as vegetables, fruits (especially apples[4]), insoluble fiber and soups.
That calorie restriction (CR) might lengthen human lifespan was suggested by various studies on laboratory animals.
However, when the studies were extended to long-lived primates (rhesus monkeys), while it was indeed found in a 2012 study by the US National Institute on Aging (NIA) that CR had benefits to immune function, motor coordination, and resistance to sarcopenia, a CR regimen implemented in rhesus monkeys of various ages did not improve survival outcomes.