1. The Science of Caloric Restriction
Caloric restriction (CR) without malnutrition is one of the most consistently validated non-genetic interventions for extending lifespan across model organisms. Reducing caloric intake by 15% to 30% reduces fasting insulin, lowers body temperature, and upregulates antioxidant defense enzymes.
Human trials (such as CALERIE) confirm that caloric restriction lowers cardiometabolic risk factors, reduces systemic inflammation, and improves mitochondrial energy production efficiency.
2. Sirtuins & NAD+ Metabolism
Caloric restriction increases cellular NAD+ levels, activating the NAD+-dependent deacetylase family of Sirtuins (SIRT1-SIRT7). Sirtuins deacetylate histones and key transcription factors (such as PGC-1alpha and FOXO), promoting mitochondrial biogenesis and DNA repair.
3. Human Physiological Adaptations to CR
- Fasting Blood Glucose & Insulin: Substantial reductions in circulating insulin and improved tissue insulin sensitivity.
- Cardiovascular Risk Factors: Lowering systolic blood pressure, serum triglycerides, and arterial stiffness.
- Systemic Inflammatory Markers: Significant decreases in circulating hs-CRP and TNF-alpha levels.
4. Sustainable Alternatives to Severe Restriction
For individuals finding continuous caloric restriction difficult, periodic fasting or high-density Mediterranean nutrition offers similar metabolic dividends without compromising lean muscle mass or energy levels.