Complex sentence: Reducing dietary fat to reduce total blood cholesterol and LDL particle numbes in adults, has long been recommended for people with familial hypercholesterolemia, although usually insufficient to achieve the desired lowering of LDL and medications which reduce cholesterol production or absorption are usually required.
Split into simpler sentences: Reducing dietary fat to reduce total blood cholesterol and LDL cholesterol in adults, is recommended for people with hypercholesterolemia. In people with very high cholesterol (for example due to familial hypercholesterolemia), diet is often insufficient to achieve the desired lowering of LDL and medications which reduce cholesterol production or absorption are usually required.