Intermittent fasting, an eating practice alternating fasting periods with normal eating, is used for weight loss and longevity. It lowers weight, fat, blood sugar, cholesterol, blood fats and blood pressure about as much as eating less daily; earlier eating may modestly aid blood sugar. Concerns: low blood sugar with diabetes medication, disordered eating in susceptible people, and slight extra muscle loss without enough protein and strength training. (Full Review)
| Marker | Target | Why |
|---|---|---|
| Fasting glucose | 75–90 mg/dL | Glucose control |
| HbA1c | <5.4% | 3-month glucose average |
| Fasting insulin | 2–6 μIU/mL | Insulin resistance |
| LDL cholesterol | <100 mg/dL (<70 mg/dL if higher risk) | Artery-clogging cholesterol |
| ApoB | <80 mg/dL (<60 mg/dL if higher risk) | Artery-clogging particle count |
| Triglycerides | <100 mg/dL | Blood fat, insulin resistance |
| hsCRP | <1.0 mg/L | Systemic inflammation |
| ALT | <25 U/L | Liver fat and injury |
| Uric acid | <5.5 mg/dL | Gout and kidney stone risk |
| eGFR and creatinine | eGFR >90 mL/min/1.73 m² | Kidney function, hydration |
| Free T3 | 3.0–4.0 pg/mL | Active thyroid hormone |
| Total testosterone (men) | 500–900 ng/dL | Androgen status |
| Lean mass (DXA), grip strength | No established target; lean loss ideally <25% of weight lost | Muscle preservation |
| Blood pressure | <120/80 mm Hg | Cardiovascular risk |
Cadence: Baseline before starting; glucose logs, blood pressure and weight trend every 4–6 weeks; repeat blood work and hormones at 3 months, then every 6–12 months once stable; body composition every 6 months