During glucose metabolism, breakdown products like malonyl-CoA inhibit carnitine palmitoyltransferase, which is involved in shuttling fatty acids for beta-oxidation.

“when you are doing glucose metabolism which most of us are doing if we are eating any carbohydrates in a meal the breakdown products of the krebs cycle including malonyl coa from glucose metabolism inhibit carnitine palmitoel transferase this is part of the system that shuttles fatty acids toward beta oxidation in the mitochondria”