Fats are just one type of lipid, a category of molecules united by their inability to mix well with water. Lipids tend to be hydrophobic, nonpolar, and made up mostly.List of Foods With Lipids. Your body uses lipids, or fats, for insulation, to cushion organs and as a source of stored energy. Dietary fats also help your body to absorb fat- soluble vitamins A, D, E and K. Healthy adults should get 2. Saturated, trans and unsaturated fats are all types of lipids, but unsaturated fats are healthier choices. If there are no C=C double bonds in the hydrocarbon chain, then it is a saturated fatty acid (i.e. These fatty acids form straight chains. ![]() Cholesterol is a type of lipid that does not provide calories and is not a necessary component of your diet. Oils are pure fats, with no carbohydrates, protein or water. Each tablespoon of canola oil provides 1. Oils also provide antioxidants, such as vitamin E and selenium. Olive oil is particularly high in monounsaturated fats, which reduce blood pressure and cholesterol, while flaxseed, canola and soybean oil contain heart- healthy omega- 3 fats. Stir- fry tofu, chicken or shrimp and vegetables in sesame or canola oil, use olive oil as a base for salad dressings or brush acorn squash, eggplant or zucchini with oil before roasting it.
Nuts, such as almonds, pecans, pistachios and macadamia nuts, and peanuts are high in unsaturated fats and low in unhealthy saturated fats. An ounce of cashews has 1. Walnuts also provide linolenic acid, an essential omega- 3 fat that has cardiovascular benefits. Have nuts as a snack or add them to cereal, vegetables or chili. A cup of sliced avocado has 2. It contains 1. 4. Avocados also provide vitamin C, an antioxidant vitamin, and dietary fiber, a plant nutrient that can help lower your cholesterol levels. Make guacamole with garlic, tomatoes and lime juice, mix avocados into soup to thicken it or use avocado slices in burritos and sandwiches. A 3- ounce portion of cooked Atlantic salmon provides 1. Other fatty fish include mackerel, tuna, herring, anchovies and sardines. To increase your intake of omega- 3 fats, make a herring and apple salad with Greek yogurt, use canned tuna or salmon and broccoli to make a casserole or toss sardines with tomato sauce or olive oil and whole- wheat pasta. Choose sources of fats that are highly unsaturated instead of highly saturated to lower your cholesterol levels and reduce your risk of heart disease. Limit your intake of butter, fatty meats and full- fat cheese to limit your saturated fat consumption. Also try to avoid trans fats, which increase your risk for heart disease. Trans fats can be in fried foods and partially hydrogenated oils found in some processed snack foods, such as sandwich cookies, snack cakes and crackers. High- fat foods can be high- calorie, so monitor your portion sizes to avoid unwanted weight gain. Eggs and egg- containing dishes are the leading sources of cholesterol in the average American diet, providing 2. A large egg yolk contains 2. Your body can make enough of its own cholesterol to meet your needs, so you do not need to get cholesterol from the diet. Cholesterol from your diet can raise your levels of low- density lipoprotein, or . Chicken and beef are other major sources of cholesterol in the typical American diet. Lipids: definition, classification, functions. What are lipids? Fig. High Fat/Oil Foods. Lipids, together with carbohydrates, proteins and nucleic acids, are one of the four major classes of biologically essential organic molecules found in all living organisms; their amounts and quality in diet are able to influence cell, tissue and body physiology. Unlike carbohydrates, proteins and nucleic acids they aren’t polymers but small molecules, with a molecular weights that range between 1. The little or absent water- solubility of many of them means that they are subject to special treatments at all stages of their utilization, that is in the course of digestion, absorption, transport, storage and use. Classification of lipids. They may be classified based on their physical properties at room temperature (solid or liquid, respectively fats and oils), on polarity, or on their essentiality for humans, but the preferable classification is based on their structure. Based on structure, they can be classified in three major groups. Simple lipids. They consist of two types of structural moieties. They include: glyceryl esters that is esters of glycerol and fatty acids: e. Complex lipids. They consist of more than two types of structural moieties. They include: phospholipids that is glycerol esters of fatty acids; phosphoric acid, and other groups containing nitrogen; phosphatidic acid that is diacylglycerol esterified to phosphoric acid; phosphatidylcholine that is phosphatidic acid linked to choline, also called lecithin; phosphatidylethanolamine; phosphatidylserine; posphatidylinositol; phosphatidyl acylglycerol in which more than one glycerol molecule is esterified to phosphoric acid: e. Derived lipids. They occur as such or are released from the other two major groups because of hydrolysis that is are the building blocks for simple and complex lipids. They include: fatty acids and alcohols; fat soluble vitamins A, D, E and K; hydrocarbons; sterols. Classification adapted from: Bloor W. R. Proc Soc Exp Biol Med, 1. Christie W. W. 2. Functions of lipids. They are stored in adipose tissue (triglycerides) and are one of the major energy source. Lipids are the best energy source for humans since at a parity of weight they provide the major part of calories: if carbohydrates, on average, gives 4 kcal/g, as proteins, lipids provide, on average, 9 kcal/g. Moreover, they can be present in foods without there are also fiber or water (for polysaccharides 2 g water/g) allowing to contain a great quantity of energy in a little weight. Mostly of Nutrition Organizations recommend that lipids must contribute up to 3. Some lipids are essential nutrients like fat- soluble vitamins A, (necessary for vision) and D (necessary for calcium metabolism), present in some fats and oils of animal origin, vitamin E (prevention of autoxidation of unsaturated lipids), present in vegetable oils, and vitamin K (normal clotting of blood) present in green leaves, essential fatty acids, in particular linoleic and . This lipoprotein coating is called myelin sheath. On digestive tract they facilitate the digestive process depressing gastric secretion, slowing gastric emptying and stimulating biliary and pancreatic flow. Bile salts (by- products of cholesterol) are natural detergents synthesized in the liver and secreted into bile. They solubilize phospholipids and cholesterol in the bile, permitting the secretion of cholesterol into the intestine (the excretion of both cholesterol and bile salts is the major way by which cholesterol is removed from the body). Bile salts also aid in the digestion and absorption of fat and soluble- fat vitamins in gut. In many animals, some lipids are secreted into external environment and act as pheromones that attract or repel other organisms. They affect the texture and flavor of food and so its palatability. Food manufacturers use fat for its textural properties, e. Chefs know that fat addiction add to the palatability of meal and increase satiety after a meal. References. Akoh C. C. 2. 00. 8Arienti G. Le basi molecolari della nutrizione. Seconda edizione. Piccin, 2. 00. 3Bender D. A. 2. 00. 6, 8th Edition. Woodhead Publishing. Oxford. Bergstroem S., Danielsson H., Klenberg D. The enzymatic conversion of essential fatty acids into prostaglandins. J Biol Chem 1. 96. PC4. 00. 6- PC4. 00. Cozzani I. Piccin Editore, 2. Giampietro M. L’alimentazione per l’esercizio fisico e lo sport. Il Pensiero Scientifico Editore. Prima edizione 2. Mahan L. K., Escott- Stump S.: “Krause’s foods, nutrition, and diet therapy” 1. Rosenthal M. D., Glew R. H. Mediacal biochemistry. Human metabolism in health and disease. John Wiley & Sons, Inc. Shils M. E., Olson J. A., Shike M., Ross A. C.: “Modern nutrition in health and disease” 9th ed. Stipanuk M. H. Biochemical and physiological aspects of human nutrition. Saunders Company- An imprint of Elsevier Science, 2.
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