Ketogenic Diet

What it is

The classical ketogenic diet provides ~70–80% calories from fat, ~10–20% from protein, and ~5–10% (typically <30–50 g/day) from carbohydrate. Reduced glucose availability drives hepatic ketone-body production (β-hydroxybutyrate, acetoacetate) which serve as alternative fuel for brain and muscle.

Established medical uses

• Refractory paediatric epilepsy — reduces seizures in many children.
• Glut-1 deficiency syndrome.
• Some metabolic encephalopathies.

Other-condition evidence

• Type-2 diabetes: substantial short-term improvements in glycaemia, weight, and lipid profile; long-term adherence is the main obstacle.
• Weight loss: works, mostly via appetite suppression and water loss; not clearly superior to other restricted diets when calories are matched.
• Athletic performance: mixed; impairs glycolytic peak performance.
• Neurodegeneration: small early trials suggest cognitive benefit in MCI/early Alzheimer’s; not yet established.

Longevity considerations

• β-hydroxybutyrate is a HDAC inhibitor and an NLRP3-inflammasome inhibitor — mechanistically plausible longevity signals.
• Continuous ketogenesis (vs. cyclic) may not be optimal; rodent data hint at metabolic inflexibility on permanent keto.
• LDL/apoB often rises substantially on ketogenic eating in some individuals (“lean mass hyper-responder” phenotype), with uncertain long-term ASCVD implications.

Practical considerations

• Strict ketosis is hard to sustain.
• Tracking ketones (urine strips, blood meter) helps verify.
• Sodium/potassium balance and adequate fibre matter.
• Bone-density loss reported on long-term strict keto.

Related entries

Caloric restriction, Intermittent fasting, ApoB.