NUTRITIONAL ASPECT OF MACRONUTRIENT LIPIDS Nutrition Department Medical Faculty Padjadjaran University

DEFINITION Lipids An organic compounds composed by C, H, and O, that includes triglycerides (fat and oils), phospholipids and sterols. Fats Lipids in foods, or in the body, both are composed mostly of triglycerides (TG) Oils Liquids fats (at room temperature) Characteristic : Hydrophobic, soluble in ether/alcohol

Classification 1.Simple Lipids Neutral fats (mono/di/triglycerides  glycerol + fatty acid) A.Based on chain length of fatty acid Short Chain (SCFA) Fatty acids with 6 carbon or less, such as butiric acid in butter.

Medium Chain Fatty Acids (MCT) Fatty acids contain between 8 and 12 carbons, usually encountered in synthetic fats, such as lauric acid in coconut oil. Long Chain Fatty Acids (LCT) Fatty acids contain up to 27 carbons with chain length of 16 or 18, most natural fats consist LCT.

B.Based on degree of saturation Saturated Fatty Acids (SAFA) Fatty acid that all carbon chain containing hydrogen. SAFA sources : –Meat and products, poultry, especially the skin layer –Dairy products: milk, cheese, yoghurt, and ice cream –Plants : coconut oil, palm oil –Food containing shortening and margarine : cake, snack, instant noodle.

Unsaturated Fatty Acids Fatty acid contains one or more double bonds: –Mononsaturated Fatty Acids (MUFA) Contain only one double bonds. Food sources : Avocado, olive, peanut, almond.

–Polyunsaturated Fatty Acid (PUFA) Contain two or more double bonds. Essential fatty acid. Based on the position of the first double bond : –Omega-6 18:2 : linoleic acid : leavy vegetable, seeds, nuts, grains, vegetable oil. 20:4 : arachidonic acid : meat, or can be made from linoleic acid.

–Omega-3 Linoleic acids : fats and oill (canola, soybean, walnut, wheat germ, margarine and shorteing), nuts and seeds (butternuts, walnuts, soybean kernels), vegetables (soybeans). EPA & DHA : Human milk, shelfish and fish (mackerel, salmon, tuna, herring, sardines), or can be made from linolenic acid

2.Compound lipids Phospholipid : compound of TG + niitrogen base + phosphate, phospholipid is available in every cells as cell structure, cell membrane, and cytoplasma. Glycolipid : TG + CH: as cell structure and cell membrane. Lipoprotein : TG + protein, as lipid transport in the blood : chylomicron, VLDL, LDL, HDL.

3.Derived Lipids Sterol : cholesterol, sources : brain, liver, egg, yolk. Steroids hormones, Vit D, bile salts. 4.Miscellaneous Lipids Carotenoids and Vit A, Vit E, Vit K.

Lipid Digestion Mouth : partial digestion of lingual lipase in adult and active in infant. Stomach : continous digestion by lingual lipase. Small Intestin Release of cholecystokinine hormone Emulsification by bile acid Digestion by lipase pancreas  fatty acid and glycerol

Lipid Absorption SCFA, MCT, glycerol  absorbed directly into the bloodstream. Monoglycerides, LCT  micelles  TG + cholesterol + phospholipid merged into chylomicron  the lymphatic system

Lipid Transport Lipid as group lipoprotein : Chylomicron: from intestinal  body VLDL : from liver  various tissues in the body LDL : circulate throughout the body (bloodstream and tissues) HDL : transport cholesterol back to the liver from the cells

Role of Lipids Within the food : Add to the palatability of the diet and produce a satiety feeling after meal. To dissolve/as a solvent of Vit A,D,E,K Essential as fatty acid sources

Role of Lipids In the body : Energy source Helps to hold the body organs and nerves in position Vital organ protection Body temperature insulation Cell wall structure Skin and hair lubrication Aids transport and absorption of the fat soluble vitamins

Role of Cholesterol Element of cell membrane Element of bile acid Precursor of sterol hormones : estrogen, progesteron, testosterone, corticosteroid hormone

Lipid Composition in Diet Daily Fat < 30% total calorie (option 25%) SAFA < 10% total lipid PUFA ≤ 10% total lipid MUFA < 15% total lipid Cholesterol ≤ 300 mg

Health Effect of Lipid Including Diseases Related to Lipids Cardiocerebrovascular diseases  dislipidemia as major risk factor Cancer  association between total fat diet and some type of cancers (Ca Mamma, Ca Uteri) Obesity Gall stone

Normal Value of Lipid Profile Triglyceride : mg/100 ml Cholesterol : 200 mg/100 ml LDL < 150 mg/100 ml HDL > 40 mg/100 ml

Factors that improve HDL value Weight control Quit smoking MUFA/PUFA instead of SAFA in the diet Soluble fibers Antioxidant Physical activity

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