Cutting carbohydrate enough to burn fat-derived fuels reliably lowers body fat and blood sugar, calms seizure disorders and lifts low mood. It also raises the cholesterol-carrying particles most tied to heart disease. Muscle can be lost unless protein and training are protected, replacement foods matter more than the restriction, and no study has measured whether anyone lives longer. (Full Review)
| Marker | Target | Why |
|---|---|---|
| Apolipoprotein B | < 80 mg/dL; < 60 if plaque present | Counts the atherogenic particles this diet is most likely to raise |
| LDL cholesterol | < 100 mg/dL, and no more than a 30% rise from baseline | Tracks the high-quality-evidence adverse effect |
| Lipoprotein(a) | < 30 mg/dL (< 75 nmol/L) | Genetically fixed particle that multiplies the harm of any cholesterol rise |
| Triglycerides | 50–90 mg/dL | Fastest-improving marker; confirms the diet is working metabolically |
| HDL cholesterol | > 55 mg/dL men, > 65 mg/dL women | Rises predictably; a flat response suggests poor adherence |
| HbA1c | 4.8–5.4% | Confirms the glycaemic benefit and detects loss of control |
| Fasting insulin | 2–5 µIU/mL | The earliest marker of the diet's core metabolic effect |
| β-Hydroxybutyrate (blood) | 0.5–2.0 mmol/L metabolic; 2–4 mmol/L epilepsy | Confirms ketosis and prevents chasing meaningless higher numbers |
| Magnesium (RBC) | 5.0–6.5 mg/dL | Depleted by ketogenic diuresis; drives cramps and insomnia |
| Sodium and potassium | Sodium 138–142 mmol/L; potassium 4.0–4.5 mmol/L | Detects the losses behind adaptation symptoms and fainting |
| Uric acid | 3.5–5.5 mg/dL | Rises early and drives the uric-acid stones that predominate on this diet |
| Free T3 and TSH | Free T3 3.0–4.0 pg/mL; TSH 0.5–2.0 mIU/L | Detects the active-thyroid-hormone fall this diet produces |
| eGFR and creatinine | eGFR > 90 mL/min/1.73 m² | Kidney function guards the stone and dehydration risks |
| 25-hydroxyvitamin D | 40–60 ng/mL | Underpins the calcium handling that protects bone during ketosis |
| Body composition (lean mass) | No established target; track change from the individual's own baseline | Lean-mass loss is the risk most directly opposed to a longevity goal |
| Coronary artery calcium score | 0 Agatston units | Turns a lipid change into a personal plaque figure |
Cadence: Baseline testing before starting; electrolytes and magnesium at 2 weeks; full lipid and metabolic panel at 8 weeks and 6 months, then every 6–12 months while the diet continues; body composition at 3 and 6 months; bone density every 24 months above age 50 or with a fracture history.