CALERIE trial (2007-2015)
The CALERIE trial at three US sites tested 25% calorie restriction in 218 healthy, non-obese adults aged 21 to 50 for two years. It was the longest calorie-restriction trial ever conducted in humans.
Calorie-restricted participants lost weight, showed improved metabolic markers, and exhibited modest changes in aging-related biomarkers.
The trial showed lifestyle interventions can shift aging markers, but translating those shifts into extended lifespan remains unproven in humans.
The Sydney trial tests a similar hypothesis over a much shorter window: 4 weeks instead of 2 years, manipulating macronutrient balance rather than total calorie intake.
