Paid episode

The full episode is only available to paid subscribers of Harnessing the Power of Nutrients

25. How Insulin Stops Fat-Burning

Lesson 25 of Masterclass With Masterjohn: Energy Metabolism

If you’re having issues with playing the video above, play this instead:

Insulin prevents fat-burning in part by locking fat in adipose tissue and in part by shutting down transport of fatty acids into the mitochondrion inside cells.

By downregulating lipoprotein lipase (LPL) at heart and skeletal muscle and upregulating it at adipose tissue, insulin shifts dietary fat away from heart and muscle and toward adipose tissue. By downregulating hormone-sensitive lipase in adipose tissue, it prevents the release of free fatty acids from adipose tissue into the blood.

At the cellular level, insulin leads to the phosphorylation and deactivation of AMPK. Since AMPK inhibits acetyl CoA carboxylase, insulin-mediated deactivation of AMPK leads to activation of acetyl CoA carboxylase and the conversion of acetyl CoA to malonyl CoA. Malonyl CoA inhibits carnitine palmitoyl transferase-1 (CPT-1) and thus blocks the transport of fatty acids into the mitochondrion.

Nevertheless, all of these steps are also regulated at the most fundamental level by energy status, as covered in lesson 22. Further, insulin stimulates the burning of carbohydrate for energy, as covered in lesson 24. So, is insulin’s blockade of fat-burning sufficient to cause net fat storage, or does this critically depend on energy balance? This question will be answered in the next lesson.

The audio and video of the first three lessons of this course are available to everyone for preview, but lessons 4-39 are for Masterpass members only. Start a preview from the beginning here. To learn more about the Masterpass, click here.

The full video is for paid subscribers

Harnessing the Power of Nutrients
Masterclass With Masterjohn: Energy Metabolism
This is a course with 39 lessons on the biochemistry of how we burn carbohydrate and fat for fuel.
Authors
Chris Masterjohn, PhD