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fats.pptx
- 1. Lecture 3 .Fats Rusudan Kvanchakhadze, Head of the Clinical and Scientific Department of the Georgian Nutrition Association
- 2. Dietary Importance ofFats Fats are a concentrated fuel source for the human energy system. A large amount of energy can be stored in a relatively small space within adipose tissue as compared with carbohydrates that are stored as glycogen. As such, fats supplement carbohydrates (the primary fuel) as an additional energy source. In food, fats may be in the form of either solid fat or liquid oil.
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- 4. What are Fats Fats,are organic compounds that are necessary for good health. The overall name of the chemical group of fats and fat-related compounds is lipids, which comes from the Greek word lipos, meaning “fat.” The word lipid appears in com-bination words that are used for fat-related health conditions. For example, an elevated level of blood fat is called hyperlipidemia.
- 5. What are Fats Lipidsdiffer in many ways from the other macronutrients –carbohydrates and proteins- despite the fact that they contain the same three elements, carbon, hydrogen and oxygen. In addition to the different chemical structure, lipids are not water soluble. Lipids are classified according to chemical structure into three categories: triglycerides, phospholipids, and sterols. Each plays different roles, yet all are necessary for body to function properly.
- 6. Triglycerides Fats acids arecarbon chains with an oxygen-containing carboxyl group at the glycerol and a hydrogen-containing methyl group at the terminal end. Fatty acids come in several forms based on chain length and saturation. The number of carbons atoms determines the length of the fatty acids chain, whereas the degree of saturation refers to the number of double and single bonds between the carbon molecules . Fatty acids can be termed unsaturated if there are double bonds on the carbon chain or saturated if no double bonds exist. In nature, most triglycerides exist with a mixture of fatty acids, both saturated and unsaturated, though some have more of one type than another in the mixture.
- 7. Unsaturated FATS include bothmonounsaturated and polyunsaturated fats. Unsaturated fats have a least one double bond on the carbon chain. These fat tend to be liquid at room temperature because this configuration lowers the melting point of the fat compared to fats with no double bonds. Unsaturated fats are classified according to the length of the carbon chain and the placement of the first double bond between carbons from the terminal, or omega, end of the chain. Monounsaturated fats have only one double bond on the carbon chain. The most common dietary monounsaturated fat is calls oleic acids, containing 18 carbons.
- 8. Health effects ofoleic acids Oleic acid is a common monounsaturated fat in human diet. Monounsaturated fat consumption has been associated with decreased low-density lipoprotein (LDL) cholesterol, and possibly with increased high- density lipoprotein (HDL) cholesterol, Oleic acid may be responsible for the hypotensive (blood pressure reducing) effects of olive oil that is considered a health benefit.
- 9. Unsaturated FATS As denotedby the name, polyunsaturated fats have more than one double bond. Two classifications of polyunsaturated fats are omega-3 and omega-6 fatty acids. The first double bonds on these carbon chains are at the third carbon and sixth carbon, respectively, from the omega end of the fatty acids. Two polyunsaturated fats, linolenic acids and linoleic acids are considered essential fatty acids.
- 10. Unsaturated FATS Essential fattyacids play a role in maintaining healthy skin and promoting normal growth in children. Essential fatty acids make up part of our cell membranes and are involved in blood clotting and inflammation. Even though the body cannot make essential fatty acids, deficiency is rare due to the abundance in the food supply. Deficiency of essential fatty acids occurs when intake of fat is too low or because of fat malabsorption, such as with cystic fibrosis or inflammatory bowel disease. Premature infants are at risk for essential fatty acids deficiency because of borderline stores of these fats at birth coupled with high-energy needs.
- 11. Saturated Fats andTrans Fats Trans fats are a type of fatty acid that behave like saturated fats in the body yet are not a fully saturated fat. A process called hydrogenation-a chemical process by which hydrogens are added to an unsaturated fat, thereby making it more saturated –creates a trans-fatty cid. Trans mean the hydrogen atoms are cross the carbon chain from one another, instead of the cis formation generally found in fats
- 12. Saturated Fats andTrans Fats Saturated fatty acids have no double bonds on the carbon chain and, therefore, each carbon is attached to the maximum number of hydrogen atoms. This structure gives the fatty acid more of a straight-line configuration than is seen with unsaturated fats and results in fats that are usually hard at room temperature. Exceptions are coconut and palm oils.
- 13. Palm oil is madefrom the fruit of the oil palm. And the oil obtained from the seeds of this palm tree is called palm kernel oil. Palm oil has been used in Russia relatively recently. It is ideal for baked goods as well as confectionery products, especially those intended for long-term storage. Currently, palm oil is widespread, the benefits and harms of which are still being studied, and controversy around it does not subside.
- 14. Phospholipids Like triglycerides, phospholipidshave a backbone of glycerol, but instead of having three fatty acids attached, they have only two. Instead of the third fatty acid, phospholipids have a phosphate group. To being an important part of the food supply, phospholipids are vital to our bodies. They constitute cell membranes and allow bodily fluids to exist in both fat-and water-soluble enviroments, Lecithin is the most common phospholipid in the body and is found in cell membranes and surrounding nerve fibers.
- 15. Sterols Sterols are thethird class of lipids and are composed of large, interconnected rings of carbon. Sterols are synthesized by the body and not required in the diet. Cholesterol is most well-known sterol, whereas vitamin D, testosterone, and estrogen are other familiar examples. Although plant and animal foods contain sterols, only foods that come from an animal contain cholesterol
- 16. Functions of Fatsin the body • Transports fat-soluble vitamins A,D, E and K • Cushions and protects organs • Insulated body to maintain core temperature • Provides lubrication • Source of stored energy • Component of cell membranes • Component of myelin in the nervous system • Building block for synthesis of other lipid-based compounds, such hormones, vitamin D, prostaglandins, and bile
- 17. Fat recommendations • Consumeless than 10 percent of calories from saturated fatty acids and less than 300 mg/day of cholesterol, and keep trans-fatty acids consumption as low as possible • Keep total fat intake between 20% and 35% of calories, with most fats coming from sources of polyunsaturated fatty acids such as fish, nuts and vegetables oils • When selecting and preparing meat, poultry, dry beans and milk or milk products, make choices that are lean, low fat or fat free. • Limit intake of fats and oils in saturated and/or trans-fatty acids, and choose products low in such fats and oils
- 18. Wellness Concerns Fat isoften implicated when talking about disease progression and prevention, most commonly when discussing risk of heart disease and cancer. Research supports the role that too much fat can play in some disease processes but is less clear with others. Additionally, higher intake of same fats is being recommended for some medical conditions, such as omega-3 fatty acids used too treat high blood triglyceride levels.
- 19. Obesity Regarding of thetype of fat, high-fat are generally high in calories and can increase the risk for obesity. Obesity occurs as a result of any combinations of excess energy intake and decreased energy expenditure. Excess energy intake can occur with excess intake of any macronutrient, carbohydrate, protein, or fat.
- 20. Obesity High–fat foods areoften to blame for excess calories intake because they are generally more calorically dense than high-carbohydrate or protein foods, making it easier to consume extra calories in serving. When working with an individual who is seeking weight management advise, the nurse can strategize with the client about sources of excess calories in the diet from high-fat foods and suggest lower-fat, lower- calorie alternativies.
- 21. Cardiovascular Disease (CVD) CVDis the general term that describes all diseases of the heart and blood vessels. The cholesterol levels in our blood can promote or serve as protection against cardiovascular disease. Blood cholesterol level has several components that can be influenced by diet, specifically the amount and types of fat eaten. Blood cholesterol is comprised of several components, including LDL (“bad” cholesterol” and HDL (“good” cholesterol).
- 22. Dietary omega-3 fattyacids Dietary omega-3 fatty acids are recommended for two distinct purposes in those with lipid disorders and CVD. First increased intake of omega-3 fats in supplemental form is part of the treatment of high blood triglyceride level, a risk factor for CVD. Second, intake of omega-3 fats is associated with a decreased risk of CVD and sudden death.
- 23. Cancer Although concern existsthat high intake of fat is associated with increased risk of some cancers, research results have been inconsistent. Research has encompassed all types of fats, including trans fats and omega-6 and omega-3 fats with varying results. Obesity, which often accompanies a higher-fat diet, has a positive association with prostate cancer risk, as does saturated fat intake. A low-fat diet may reduce the incidence of ovarian cancer among postmenopausal women
- 24. Inflammatory Diseases andOther Conditions Many conditions and diseases in the body are caused by an inflammatory response. Rheumatoid arthritis and inflammatory bowel disease are examples. Omega-3 fats are often touted in the popular press for the ability to treat these conditions, but the amount of scientific evidence on this subject varies. The effect of omega-3 fats on neurological and cognitive conditions also been the subject of research. Mood disorders, such as depression, and attention-deficit hyperactivity disorder are examples.
- 25. Fish intake inat risk population The cardiovascular benefits of omega-3 fats from fish and fish oil sources are well recognized. As a result the American Heart Association has made recommendations for consuming two servings of fish per week. However, contamination of some fish with methylmercury is cause for concern, especially in children and pregnant females, because of he negative effects on development of the brain and nervous system. Mercury levels vary among fish species depending on environmental exposure to pollutants and place on the food chain
- 26. Dietary Guidelines forAmericans • Consume less than 10% of calories from saturated fatty acids by replacing them with monounsaturated and polyunsaturated fatty acids. • Consume less than 300mg/day of cholesterol. • Keep trans-fatty acid consumption as low as possible by limiting foods that contain synthetic sources of trans fats (e.g., partially hydrogenated oils) and by limiting other solid fats. • Reduce the intake of calories from solid fats. • Choose fat-free or low-fat milk and milk products. • Replace protein foods that are higher in solid fats with choices that are lower in solid fats and calories and/or are sources of oils. • Use oils to replace solid fats where possible
- 27. Digestion of somefats can begin in the mouth where lingual lipase breaks down some short chain lipids into diglycerides. However fats are mainly digested in the small intestine. The presence of fat in the small intestine produces hormones that stimulate the release of pancreatic lipase from the pancreas and bile from the liver which helps in the emulsification of fats for absorption of fatty acids. Complete digestion of one molecule of fat (a triglyceride) results a mixture of fatty acids, mono- and diglycerides, as well as some undigested triglycerides, but no free glycerol molecules.
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