Lipids (Fats) - Diet and Nutrition

Lipids (Fats)

Lipids are chemical substances that are relatively insoluble in water. The most familiar is triglyceride (body fat). Other lipids, including cholesterol and lecithin, are essential components of cell membranes. Vitamins A, D, E, and K are also lipids, as are substances in the liver bile (bile acids) which help digest fats.

The lipids that most people eat in ordinary foods come in three principal forms: cholesterol, saturated fats (found primarily in animal products), and unsaturated fats–either polyunsaturated fats (as in sunflower and safflower oil) or monounsaturated fats (as in olive and canola oil). Cholesterol levels depend largely on the type of fats an individual consumes. In general, saturated fats raise cholesterol levels in the blood, while unsaturated fats appear to reduce cholesterol, including “bad” (LDL) cholesterol, without adverse side effects.

Most Americans are now familiar with the danger of consuming too much fat, especially saturated fats, which are believed to contribute to heart disease. Saturated fats are found in animal foods such as beef, pork, lamb, veal, egg yolks, whole milk, cream, cheese, ice cream, butter and lard, chocolate, coconuts, and oils often used in processed foods, like coconut, palm, and palm-kernel. Many studies have shown a relationship between dietary fat consumption and cancer of the breast, colon, and prostate gland-one reason experts recommend eating no more than 10% of calories in the diet as saturated fat.