Saturated fats are the 'bad cholesterol' fats. They're triglycerides, some being quite large molecules, containing no double bond carbon atoms with active single bond, hydrogenated fatty acids. This makes them hihgly combinative, and it's also what makes them 'sticky', meaning they bond easily with other materials.

This is a typical chemical structure for formation of plaque and other major metabolic problems. These large, chemically active but usually biologically useless and destructive fatty molecules are the reasons saturated fats are universally condemned by dietitians and medical professionals.