In 2007, researchers at the Duke University School of Medicine studying caloric restriction in humans set out on Phase 2 of what were called the CALERIE Trials (Comprehensive Assessment of Long term Effects of Reducing Intake of Energy).
Completed in 2012, the study created the most comprehensive randomized placebo-controlled trial dataset that had ever been complied on the effects of caloric restriction, which since the early 2000s has been hypothesized as an ameliorator of the various effects of aging.
Under such a hypothesis it’s no wonder so many researchers were eager to get their hands on the data, and why more than 80 studies have been published between the Phase 1 and Phase 2 results.
Comprehensive physiologic, psychologic, quality of life, and cognitive assessments were conducted on the participants, and extensive collections of biological samples were taken that include serum, plasma, urine, and biopsies from skeletal muscle and adipose tissue, further flushing out the thoroughness of the data.
All the resulting papers examine the CALERIE study cohort, which consisted of 218 non-obese individuals between the ages of 20 and 50. 143 of them had a diet of 25% reduced calorie intake (CR group), and 75 were allowed total eating freedom (AL group). Assessments were generally made every 6-12 months.
In a special 2-part series, WaL will analyze the more than 80 studies produced in the wake of this monumental trial, and parse out what an individual can gain from calorie restriction.