What’s the Difference between Fat and Cholesterol? Cholesterol is a type of fat that exists in all our cell membranes. It is vital for such functions as nerve transmission, the formation of vitamin D and the formation of bile. Approximately 80% of cholesterol is produced in your liver, with the other 20% coming from your diet. It’s only found in animal products, not in vegetable oils like avocado or olive. Shellfish, for example, contain very little fat, but a high level of cholesterol, whilst nut butters are high in fat and low in cholesterol. Cholesterol has to travel in the bloodstream and in order to do so, is combined with a protein to create a lipoprotein, of which there are two main types: LDL (or “bad), which carry cholesterol to the artery wall, and HDL (“good”), which helps to return cholesterol to the liver. High LDL causes damaged and inflamed arterial walls, also depositing saturated fats and calcium, called arterial plaque or atheroma. The balance of these two lipoproteins in the blood is more important than the total cholesterol.