Eating meaningfully less while staying well-nourished reliably lowers weight, blood fats, blood sugar, blood pressure, and inflammation, and may modestly slow some aging markers — clearest for those carrying excess fat. Trade-offs include muscle and bone loss, hunger, and lower energy use. Whether it lengthens human life remains unknown, and almost no one sustains it. (Full Review)
| Marker | Target | Why |
|---|---|---|
| Fasting glucose | 75–85 mg/dL | Tracks glycemic improvement |
| Fasting insulin | 2–5 µIU/mL | Sensitive marker of insulin sensitivity |
| LDL cholesterol | < 100 mg/dL (lower if high-risk) | Cardiovascular risk; falls with calorie restriction |
| Triglycerides | < 80 mg/dL | Responsive to energy restriction |
| hsCRP | < 1.0 mg/L | Tracks chronic inflammation |
| Bone mineral density (DEXA) | T-score above −1.0 | Detects CR-driven bone loss |
| Appendicular lean mass (DEXA) | Maintained from baseline | Detects excess muscle loss |
| Vitamin D (25-OH) | 30–50 ng/mL | Supports bone protection |
| TSH | 0.5–2.5 µIU/mL | Detects restriction-driven thyroid slowing |
| Free T3 | Mid-to-upper reference | Sensitive to metabolic adaptation |
Cadence: Lipids, glucose, and weight at ~1 and 3 months, then every 3–6 months; body composition and bone density by DEXA at baseline, then every 12–24 months.