As ill-reputed as they have become in recent years, fats and oils are essential for good health -- in moderation. Like carbohydrates and proteins, they are organic compounds with a backbone that consists of carbon, hydrogen and oxygen.
Fats and oils are all lipids, and the two terms are often used interchangeably. Strictly speaking, however, fats are solid at room temperature, while oils are liquid. They provide your body with fatty acids, which play key metabolic and structural roles in physiology.
*Classification
Fatty acids are the building blocks of fats and oils. They fall into three broad categories: saturated, unsaturated and trans. Saturated fatty acids are usually found in such animal products as butter, milk, yogurt, cheese, mayonnaise, cream and meats, as well as limited plant foods, including palm and coconut oils. The University of Maryland Medical Center recommends limiting their intake because of their role in increasing bad cholesterol. In contrast, unsaturated fatty acids help reduce blood cholesterol and abound in fish, some vegetables oils, seeds, nuts, soybeans and olives. Trans-fatty acids, which also increase cholesterol levels and the risk of heart diseases primarily occur in margarine and processed foods.
-Essential Fatty Acids:
Two fatty acids, namely linoleic and linolenic acids, are essential, meaning that your body cannot produce them and must therefore get them from your diet. Nuts, olives, avocados and various oils are rich sources. Essential fatty acids play a role in blood coagulation, brain development and the regulation of inflammation in your body. According to biochemist Pamela Champe, Ph.D., they also lower blood cholesterol and help prevent heart disease. Deficiencies can lead to liver disorders, reproductive problems, poor vision, memory problems and skin lesions.
-Vitamin Absorption
Because some nutrients are fat-soluble, you should not eliminate all fats from your diet. For instance, your body needs fats to absorb and transport vitamins A, D, E, K, as well as carotenoids. A lack of fats in your diet can therefore lead to deficiencies, exposing you to health problems. Vitamin D deficiency, for example, can result in bone weakness and deformations, while potential consequences of vitamin A deficiency include anemia, impotence, night blindness, growth retardation and an increased risk of infection.
-Energy Supply and Storage
Fat is the slowest but most energy-dense macronutrient, supplying 9 calories per gram. In contrast, each gram of carbohydrate or protein only yields 4 calories of energy. As a result, fats represent your body's largest energy storage form. Champe indicates that the body taps into fat stores after it has consumed the calories from easier-to-break down nutrients like carbohydrates and protein. Fat storage is a consequence of excessive calorie intake, whether it be from excess carbohydrates, protein or dietary fats.
-Structural Functions and Development
Just like fences, cellular barriers play a protective role by regulating the type of substances that enter and leave your cells. Because of their water-repellent nature, fats can act as a barrier. They also give structure to your cell membranes. Cholesterol, for instance, is a critical fat-like substance that occurs in all cell membranes. Your body needs it to make bile acids, steroid hormones and vitamin D. Fats also give structure to lipoproteins, a family of proteins that help transport fatty compounds like cholesterol throughout your bloodstream. What's more, fats assist with normal growth and development.
-other functions
Fat acts as an insulator and provides protection to your organs by cushioning them. Also, fatty acids work as signaling molecules, helping your cells communicate with each other to ensure proper body function. Linus Pauling Institute professor Donald B. Jump, Ph.D., adds that fatty acids regulate gene expression and can behave like hormones to control the types of protein your cells produce. Lastly, fats add flavor and texture to food and help maintain skin and hair health.
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