How does greasy food clog your arteries?

It's not the grease, it's the cholesterol. cholesterol can be found in many foods that arn't fatty as well.

Its based on the idea that the more fat you eat the more fats will be present in your blood stream, it was suggested that animal fats in particular lead to more Low density fats which could be deposited in the arteries. Other fats like some vegetable oils and fish oils increased the level of high density fats which seemed to protect the arteries. Unfortunately it isn't that simple, our body needs certain fats, cholesterol for instance is an important part of fats used to support tissues and is used in digestion. If these isn't enough in the diet your body just produces it. Its now thought that even though we do eat to much fat, it has less of an effect on blood fats than previously thought, however being overweight can increase blood pressure and that increases arterial damage. Blood fats are probably more effected by genetics than diet. Its also much more effective to use drugs to lower the blood fats than just to try a low fat diet.