Since cholesterol is essential for life, it is primarily synthesized from simpler substances within the body. However high levels in blood circulation, depending on how transported within lipoproteins, are strongly associated with progression of atherosclerosis. For a person of about 68 kg (150 pounds), typical total body cholesterol synthesis is about 1 g (1,000 mg) per day, and total body content is about 35 g. Typical daily additional dietary intake, in the United States and societies with similar dietary patterns, is 200–300 mg. The body compensates for cholesterol intake by reducing the amount synthesized.

Cholesterol is recycled. It is excreted by the liver via the bile into the digestive tract. Typically about 50% of the excreted cholesterol is reabsorbed by the small bowel back into the blood stream. Intestinal tract absorption is highly selective for cholesterol.

A change in diet may help reduce blood cholesterol in addition to other lifestyle modifications. Avoiding animal products may decrease the cholesterol levels in the body not through dietary cholesterol reduction alone, but primarily through a reduced saturated fat intake. Those wishing to reduce their cholesterol through a change in diet should aim to consume less than 7% of their daily calories from saturated fat and less than 200 mg of cholesterol per day, accordingly to US National Cholesterol Education Program.

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