How saturated fat reaches hepatic LDL receptors
Dietary saturated fat tends to reduce the activity and number of LDL receptors on liver cells. Because those receptors clear LDL particles from the blood, fewer working receptors means LDL cholesterol stays in circulation longer and serum LDL-C rises. This receptor-downregulation pathway is the most cited mechanism linking saturated fat intake to higher LDL-C.
Not all saturated fatty acids behave identically: lauric, myristic, and palmitic acids raise LDL-C more than stearic acid, which is largely converted to oleic acid and is closer to neutral.
Dose dependence and what the response does not tell you
Controlled feeding studies show the effect is real and roughly dose-dependent, so larger swaps of saturated fat produce larger LDL-C changes on average. Individual responses still vary with genetics, baseline diet, and the nutrient that replaces the saturated fat.
A rise in LDL-C is a risk marker, not a diagnosis, and cardiovascular risk depends on many factors beyond this single number. This diagram describes a mechanism and an average direction of effect; it is general educational information and not a substitute for advice from a qualified clinician about your own lipids.