Comprehensive Assessment of the Long Term Effects of Reducing Intake of Energy or CALERIE for short is the first known controlled randomized trial test to investigate metabolic effects of caloric restrictions in nonobese humans. 53 healthy nonobese men and women between the ages of 21-50 who cut their caloric intake by 15% over a 2 year time frame that underwent measurements for oxidative stress and metabolism were involved in this study which is the 2nd phase of it. Calorie reductions were calculated on an individual basis through the ratio of isotopes absorbed by participant molecules and tissue over 2 weeks which a technique to accurately achieve a weight maintenance calorie level.
Participants in the restricted group lost on average 9kg, with no signs of adverse effects such as excessive bone loss, menstrual disorders, or anemia noted. Researchers say that results of both trials were found to lead to improvements in both mood and health related quality of life. Factors such as antioxidant, dietary, and biological factors influence metabolism, current theories suggest that a slower metabolism is beneficial for aging and organisms which burn energy most efficiently should experience the greatest longevity. Caloric restrictions in lab animals lowers resting metabolic rate and core body temperature, this study focussed on effects of caloric restriction on age not weight loss.
CALERIE trials rejuvenated support for two long standing human aging theories which are the oxidative damage theory and slowing metabolism rate of living theory, of which one theory ties overproduction of free radicals to oxidative damage to DNA, proteins, and lipids leading to chronic diseases.
Trial participants numbers may be small and the duration short in context of a lifespan, none the less biomarkers of aging were improved in the participants. Next the researchers will be examining effects of calorie restriction in conjunction with antioxidant foods which mimic caloric restriction and establishing robust biomarkers of human aging.
