"Measuring the number of small LDL particles is the best index of carbohydrate intake I know of, better than even blood sugar and triglycerides.
In other words, increase carbohydrate intake and small LDL particles increase. Decrease carbohydrates and small LDL particles decrease.
Why?
Carbohydrates increase small LDL via a multistep process:
First step: Increased fatty acid and apoprotein B production in the liver, which leads to increased VLDL production. (Apoprotein B is the principal protein of VLDL and LDL)
Second step: Greater VLDL availability causes triglyceride-rich VLDL to interact with other particles, namely LDL and HDL, enriching them in triglycerides (via the action of cholesteryl-ester transfer protein, or CETP). Much VLDL is converted to LDL.
Third step: Triglyceride-rich LDL is "remodeled" by enzymes like hepatic lipase, which create small LDL"