A fat-like substance that is made by the body and is found naturally in animal foods such as meat, fish, poultry, eggs, and dairy products. Foods high in cholesterol include organ meats, egg yolks, and dairy fats. Cholesterol is needed to carry out functions such as hormone and vitamin production. Cholesterol is carried through the blood in small units called lipoproteins (see definition). There are two types of units that carry cholesterol: low-density lipoproteins and high-density lipoproteins (see definitions). When cholesterol levels are too high, some of the cholesterol is deposited on the walls of the blood vessels. Over time, the deposits can build up and cause the blood vessels to narrow and blood flow to decrease. The cholesterol in food, like saturated fat, tends to raise blood cholesterol, which increases the risk for heart disease. Total blood cholesterol levels above 240 mg/dl are considered high. Levels between 200 and 239 mg/dl are considered borderline high. Levels under 200 mg/dl are considered desirable.