Final answer:
Dietary cholesterol contributes to blood cholesterol levels, but the body also produces cholesterol. The liver adjusts cholesterol production based on the cholesterol level in the blood. Making dietary substitutions and reducing the consumption of saturated fats and trans fats can help lower cholesterol levels.
Step-by-step explanation:
The percentage of cholesterol that comes from diet can vary depending on several factors, including an individual's overall diet and lifestyle. While dietary cholesterol does contribute to blood cholesterol levels, it is important to note that the body also produces cholesterol on its own.
According to research, the average American consumes about 600 mg of cholesterol from animal products each day and also synthesizes approximately 1 g of cholesterol each day, mostly in the liver. The liver adjusts its cholesterol production based on the cholesterol level in the blood; if cholesterol is present in the diet, the liver reduces its synthesis. However, the reduction in cholesterol synthesis does not equal the amount of cholesterol ingested from the diet. Therefore, making dietary substitutions and reducing the consumption of saturated fats and trans fats is recommended to help lower serum cholesterol and reduce the risk of heart disease.