The latest research says that it's HDL and triglycerides which are the most important today. But doctors are still being taught outdated stuff. So long as your trigs are below 1.5mmol/L you will have big fluffy LDL not the small dense particles that stick to your arteries. Have a look at this Youtube Prof Ken Sikaris he is a lipidologist so spends all his time looking at blood. He explains it beautifully. Also if you are following a LCHF diet and do have any small dense from previous diet they should also go down over time. Aseem Malhotra cardiologist thinks the same. It's sugar that causes small dense particles and heart disease not fat.