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Lipolysis

Lipolysis is the breakdown of triglycerides stored in fat cells into free fatty acids and glycerol. It can increase fatty-acid delivery during fasting or carbohydrate restriction, although dietary fat also supplies fatty acids.

Lipolysis

Stored triglycerides are broken into fatty acids and glycerol.

  • Term
  • Measure
  • Context

What triggers lipolysis?​

Insulin suppresses adipose lipolysis, but the pathway is not an on/off switch controlled by one hormone. Catecholamines, energy demand, blood flow, and re-esterification also influence net fatty-acid release. During fasting or carbohydrate restriction, the combined hormonal and substrate environment can favor release of fatty acids and glycerol.1 The science of ketosis places that release in the wider pathway.

Where does lipolysis fit in ketone production?​

Lipolysis releases fatty acids and glycerol but does not itself produce ketone bodies. Tissues can use fatty-acid oxidation; in liver mitochondria, fatty-acid-derived acetyl-CoA can enter ketogenesis when metabolic conditions favor it. Glycerol can contribute to regulated gluconeogenesis in the liver and renal cortex.

Is lipolysis the same as losing fat?​

No. Lipolysis releases fatty acids from storage, but one release event does not establish net body-fat loss. Released fatty acids may be oxidized or re-esterified, and dietary fat also enters the body's fat pools. Body-fat change over time cannot be inferred from lipolysis, a ketone value, or a momentary fat-oxidation measurement. The benefits of the keto diet page separates scale, water, and body-fat outcomes.

Frequently Asked Questions

What causes lipolysis on keto?
Insulin suppresses adipose lipolysis, while counter-regulatory hormones, energy demand, blood flow, substrate availability, and re-esterification also affect net fatty-acid release.
Does lipolysis mean you're losing body fat?
No. It shows that stored triglycerides are being hydrolyzed. Released fatty acids may be oxidized or re-esterified, so the pathway alone cannot establish net body-fat change.
What's the difference between lipolysis and fatty acid oxidation?
Lipolysis breaks triglycerides apart into fatty acids and glycerol; fatty acid oxidation is the separate process where those fatty acids are actually burned for energy inside cells.
Does exercise increase lipolysis?
Exercise often raises catecholamines and energy demand, which can increase lipolysis. The response varies with intensity, duration, training status, and recent food intake.

See also: insulin · fatty acid oxidation · ketosis · gluconeogenesis · full glossary

Works cited​

  1. Ketogenic Diet — StatPearls, NCBI Bookshelf — August 19, 2026 https://www.ncbi.nlm.nih.gov/books/NBK499830/

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