No, dietary fat (butter, animal fats, things like these) do not clog arteries. Interesting that people who go on lc diets lower their bad cholesterol and their good cholesterol also is improved. Its all a huge lie that fat causes you to become fat and eventually kills you. Take a look at all the people here who sometimes need to ADD fat to their diets in order to break weight stalls and continue weight loss (myself included). There are tons and tons of articles on this site about that, and also tons of people who have lowered bad cholesterol and improved good by eating low carb and more fats. Do a google search on low carb diets and improving cholesterol levels. They are starting to do more studies on this and its now known that lc diets don't kill you.