A short, repeatable low-calorie eating pattern that briefly lowers calories, sugar, and protein to trigger a fasting-like state. The most consistent evidence shows modest drops in body weight, belly fat, and blood sugar, largest in those starting above ideal ranges. Broader longevity, brain, and immune claims rest mainly on animal and early studies. (Full Review)
| Marker | Target | Why |
|---|---|---|
| Fasting glucose | 70–85 mg/dL | Tracks the diet's core metabolic effect |
| HbA1c | <5.4% | Reflects longer-term blood-sugar control |
| Fasting insulin | 2–6 µIU/mL | Sensitive early marker of insulin resistance |
| IGF-1 | Mid-to-lower end of age-adjusted range | The hormone the diet most directly lowers |
| hs-CRP | <1.0 mg/L | Marker of systemic inflammation |
| Triglycerides | <80 mg/dL | Fat metabolism and cardiometabolic risk |
| LDL cholesterol | Context-dependent, generally <100 mg/dL | Cholesterol tied to heart-disease risk |
| Blood pressure | <120/80 mmHg | Safety and cardiovascular benefit tracking |
| Electrolytes (sodium, potassium) | Mid-normal range | Safety during low food intake |
| eGFR | >90 mL/min/1.73 m² | Kidney function and safety |
Cadence: Baseline in the week before the first cycle, after the first cycle, again at about 3 months (~three cycles), then every 6–12 months with continued cycling