A cyclic five-day low-calorie plant pattern copying a prolonged fast without total food withdrawal. Most consistent findings are fat loss while mostly keeping muscle, lower blood pressure, and better blood-sugar control in type 2 diabetes, especially when starting numbers are high. Mild fatigue, headache, and weakness during the five days are common. A periodic tool, not a proven lifespan therapy. (Full Review)
| Marker | Target | Why |
|---|---|---|
| Fasting glucose | 70–85 mg/dL | Tracks the fasting-mimicking diet glucose dip and diabetes risk |
| HbA1c | 4.8–5.3% | Three-month glycemic average |
| IGF-1 | Track change from own baseline (no single longevity target) | Confirms the growth-signal drop the diet is built to cause |
| Fasting insulin / HOMA-IR | Insulin 2–6 μIU/mL; HOMA-IR <1.5 | Insulin resistance improved in secondary analyses |
| LDL cholesterol | <100 mg/dL functional; <70 mg/dL if high atherosclerotic cardiovascular disease risk | Lipid shifts were inconsistent across trials |
| Triglycerides | <80–100 mg/dL | Fell more when baseline was high |
| hs-CRP | <0.5–1.0 mg/L | Inflammation marker that fell in at-risk subjects |
| eGFR / creatinine | >90 mL/min/1.73 m² when possible | Safety during a low-calorie week |
| Electrolytes (Na, K, Mg) | Stay in lab normal; Mg often targeted ~2.0–2.3 mg/dL | Headache and cramp prevention |
| Body composition (DEXA or MRI) | Fat mass down, lean mass stable versus own baseline | Distinguishes fat loss from muscle loss |
Cadence: End of the first cycle (or 5–7 days after refeed), after three monthly cycles, then every 6–12 months if cycling continues; home weight, waist, and blood pressure on day 1 and day 6 of each cycle