Fats are essential to the human body for many reasons:
- They provide energy
- They are involved in forming cell membranes
- They help provide fat-soluble vitamins such as Vitamins A, E, D and K
- They are involved in making hormones
- They provide insulation; keeping humans warm.
- They provide humans with a shock-absorbing, protective layer
Fats are made from building blocks called fatty acids. There are three types of fatty acids - saturated, monounsaturated, and polyunsaturated fatty acids. The fat in food contains a mixture of all three fatty acids, in different proportions in different foods. Saturated fats are found in butter, margarine, some blended cooking oils, meat, and meat products, whole milk and its products, and coconut and palm oil. Monounsaturated fats are found in olives, olive oil, rapeseed, canola and peanut oil, avocados, and most nuts. Polyunsaturated fats are found in fatty fish such as salmon and trout, safflower oil, seeds such as flax, hemp and sesame, and walnuts. Both polyunsaturated fats and monounsaturated fats are considered good fats because they help lower cholesterol levels. Managing a healthy cholesterol level helps decrease the risk of heart disease. However, too little of the good fats can result in chronic fatigue, obesity, and even heart problems.
Two polyunsaturated fatty acids, linoleic and alpha-linoleic acids cannot be made in the body and must be provided in the diet. These are called essential fatty acids. These two families of unsaturated fatty acids undergo various different chemical reactions in the body to produce the fatty acids necessary for numerous different and important functions within the body. More information about essential fatty acids can be found in Introduction to Natural Food Retailing, Lesson 4 - Nutritional Supplements & Therapies.
Trans fats are formed when the structure of monounsaturated and polyunsaturated fats are altered by a man-made process called hydrogenation. They are often found in a wide variety of processed & packaged foods. Trans fatty acids found in industrially produced products have been shown to have a negative effect on risk factors for cardiovascular disease. In late 2013, the FDA announced its preliminary determination that partially hydrogenated oils (PHOs), the primary dietary source of artificial trans fat in processed foods, are not “generally recognized as safe” for use in foods.