A ketogenic diet is very low in carbohydrate (often under 20–50 g/day) and higher in fat, which shifts the body toward using fat-derived ketones for fuel. Typical splits are roughly 70–75% fat, 20–25% protein, and 5–10% carb, though exact targets vary. Weight loss still comes from a calorie deficit. Very restrictive plans aren’t for everyone. People with certain medical conditions or on medication should get clinician guidance before starting.

Key facts:

  • Usually < 20–50 g carb/day
  • ~70–75% fat, 20–25% protein
  • Deficit still drives loss
  • Clinician check first if at-risk