Regulation of fatty acid metabolism ( Fatty acid biosynthesis vs breakdown)

This video gives a quick summary of fatty acid biosynthesis or breakdown and how it is regulated by hormones like insulin.Fatty acids are broken down to acetyl-CoA by means of beta oxidation inside the mitochondria, whereas fatty acids are synthesized from acetyl-CoA outside the mitochondrion, in the cytosol.But how this choice is modulated depending on the metabolic input?