Dietary Fats

Dietary Fats
In contrast to protein, dietary fats have a negative reputation because of their link to heart disease and cancer.

In some cases their negative reputation is justified although the role of dietary fat in health and disease is very complicated and not fully understood by scientists.

On the one hand, we now that certain types of fat are required for proper growth and maintenance of health, and their absence in the diet causes specific deficiency diseases.

On the other hand, too much of certain kinds of fat can increase the risk of chronic disease. Part of the confusion is that several types of fat exist in nature and are present in the food we eat. Another point of confusion is that many different names are used to describe the substance in food we commonly call “fat.”

To a chemist any molecule in food that does not dissolve in water belongs to a family of chemicals called lipids. The most important lipids in the food supply are triglycerides and cholesterol, which are chemically unrelated substances except for the fact that they do not dissolve in water.

Triglycerides are the lipids commonly known as fat, oil grease, shortening, lard, tallow, suet, ghee, and a verity of other names around the world.

A bottle of soybean oil, for example, is pure triglycerides.

We generally use term “fat” to describe triglycerides that are solid at room temperature and “oil” of they are liquid at room temperature.

Fats and oils are actually mixtures of many different types of triglycerides with different chemical properties, which explains why some mixtures are solid and some are liquid.

Triglycerides provide energy to the body and are found throughout the food supply in both animals and plant products. Cholesterol is another dietary lipid, but it is found only in animal products and cholesterol does not exist in the plant kingdom.
Dietary Fats