Dietary fats are classified as monounsaturated, polyunsaturated, and saturated, based on the structure of their fatty acids.  Monounsaturated fats from things such as avocado, peanut, flax, and olive, are good sources of fat for the body.  Like everything else, however, they need to be consumed in moderation.  Polyunsaturated fats can be obtained in foods such as nuts, seeds, and vegetable oils.  The National Cholesterol Education Program, not more than 10% of your daily caloric intake should come from polyunsaturated fats.

Animal fats from eggs, dairy products, and red meats, are high in saturated fats and cholesterol, should also be consumed in moderation.  Calories from fats are not as easily metabolized when compared to carbohydrates and protein.  As a result, they are more likely to resist being burned by the body.  Though, our bodies need fat in order to be healthy, some people mistakenly try to avoid all fats.  Good fats are vital in helping to build healthy body and brain cells, absorb key vitamins such as A, D, E, and K into the body, regulate the production of important hormones, keep the skin healthy, and provide a protective cushion for vital organs, especially the kidneys, heart, and intestines.

You have probably also heard of trans fats.  There are two broad types of trans fats found in foods: naturally-occurring and artificial trans fats. Naturally-occurring trans fats are produced in the gut of some animals and foods made from these animals (e.g., milk and meat products) may contain small quantities of these fats.  Artificial trans fats (or trans fatty acids) are created in an industrial process that adds hydrogen to liquid vegetable oils to make them more solid.  The primary dietary source for trans fats in processed food is “partially hydrogenated oils.” Look for them on the ingredient list on food packages.  In November 2013, the U.S. Food and Drug Administration (FDA) made a preliminary determination that partially hydrogenated oils are no longer Generally Recognized as Safe (GRAS) in human food.  Long before that, nutritionists have advised people to avoid them at all costs.