Fats PDF Lecture Notes

🎊 Fats Class Human Nutrition - DI1018 Created @January 9, 2025 1:38 PM Subject Lecture Reviewed Lipids provide essential fatty acids and fat soluble vitamin to the diet Fatty acids, triglycerides, phospholipid...

🎊 Fats Class Human Nutrition - DI1018 Created @January 9, 2025 1:38 PM Subject Lecture Reviewed Lipids provide essential fatty acids and fat soluble vitamin to the diet Fatty acids, triglycerides, phospholipids & sterols Atwater factor: 1 g of fat gives 9 kcal Components in fats in human body Fatty acids Building blocks of fats Triacylglycerols (Triglycerides) Fats 1  Main dietary lipids which are stored in the body Esters of fatty acids (both saturated and unsaturated) with glycerol Phospholipids contain phosphoric acid as a monoester or diesters Glycolipids contain monosaccharide residues joined through a glycosyl linkage to a lipid Cholesterol Important in the structure of cell membranes, mitochondria, lysosomes and the endoplasmic reticulum Fatty Acids (FA) made up of C,H.O Consists of methyl and acid group Example: Butyric acid, Palmitic acid Short-Chain fatty acids (SCFA) These have about 5 carbon atoms shorter the chain length, increase the solubility in water easily breakdown during digestion thin liquids oxidized easily Easier absorption Example: Butyric and caprylic : coconut oil, palm oil, goat milk Fats 2  Triglycerides 90% of fats in human body are triglycerides Stored in the form of fats in the body This ester is derived from glycerol and three fatty acids MUFA (Monounsaturated Fatty Acids) & PUFA (Polyunsaturated fatty acids) MUFA One double bond in the fatty acid chain Fats 3  Olive oil, Canola oil, sunflower oil Cashews, almonds, and hazelnuts PUFA contain more than one double bonds essential fatty acids are included Corn, sunflower Cis and Trans Fatty Acids Cis fatty acids: two hydrogen atoms attached to the double bond in the same side of the carbon chain Trans fatty acids: two hydrogen atoms bonded to the double bond in the opposite sides of the carbon chain Naturally MUFA & PUFA in cis form Phospholipids 2% of dietary lipids found in food plants and animal origin Body can synthesize soluble in water and fat Sterols less than 2% of the body cholesterol Body can synthesize Precursor (building blocks) of sex and adrenal hormones Lipoproteins particles made of proteins and fats (lipids) Fats 4  carry cholesterol through the bloodstream to cells Two groups of lipoproteins HDL (High-Density Lipoprotein) - Good cholesterol LDL (Low-Density Lipoprotein) - Bad cholesterol Essential and Non-essential fatty acids Fats that could not be synthesis in the body to meet the physiological demand of the body Fats 5  Functions of total fats 1. Energy source a. important source of energy for the heart 2. Transports cholesterol around the body 3. Steroid hormones (estrogens, testosterone) 4. Insulation material (to protect the body from cold) 5. Source for fat-soluble vitamin 6. Act as a cushion to protect body organs Functions of Essential Fatty Acids maintain growth, liver, and kidney functions Omega 9 - a structural molecule in skin Omega 3 – Visual functions and nervous functions Fats 6  Mainly contribute to the Inflammation of the skin maintain blood pressure and immune functions Deficiency of EFA causes: Skin Pigmentation: This means changes in the color of the skin. A deficiency might lead to either darkening or lightening of the skin in certain areas. Excess Sebum Secretion: Sebum is the oily substance produced by sebaceous glands in the skin. Excessive production can lead to oily skin and potentially acne. Increased Skin Permeability: This refers to the skin becoming more prone to allowing substances to pass through it. Increased permeability can lead to the skin being less effective as a barrier, potentially resulting in dryness, irritation, or susceptibility to infections. Functions of MUFA (Monounsaturated Fatty Acids) Reduce bad cholesterol (LDL) Reduce the risk of heart cancer and stroke Anti-inflammatory effect cell development Provide vitamin E Functions of PUFA (Polyunsaturated Fatty Acids) Acts as precursors for messengers (eicosanoids, docosanoids) They regulate inflammation, immunity, pain, sleep Prevent insulin resistance/diabetes Reduce LDL Stabilize heart rhythms Functions of Cholesterol Fats 7  The building block of vitamin D and steroid hormones Repair body tissues Functions of Lipoproteins Absorb fat from diets Transport triglycerides (the most common type of fat (lipid) in the blood and are used as a major source of energy) from liver to other tissues remove excess cholesterol from tissues Digestion and Absorption of Fats 1. Digestion of fats a. triglycerides are broken into smaller peices i. glycerol ii. monoglycerides iii. fatty acids 2. Formation of Micelles 3. Migration into Villi a. triglycerides are synthesized and are packed into chylomicrons (Lipoproteins) b. These enter the lymph c. small lipid fragments enter to the blood Fats 8  Transportation of fats Chylomicrons transport fats in the bloodstream, releasing fatty acids (FA) to cells. Some free fatty acids (FFAs) are used for energy, while others are bound to albumin and stored as triglycerides in muscles. The remaining fats (triglycerides, cholesterol, phospholipids) are transported to the liver for processing. In the liver, fats are repackaged into VLDL (Very Low-Density Lipoproteins), which enter circulation, release lipids, and become LDL (Low-Density Lipoproteins). HDL (High-Density Lipoproteins), formed in the liver and intestines, carry cholesterol and fats back to the liver for processing. LDL is considered a risk factor for heart disease (bad fats), while HDL helps remove excess cholesterol (good fats). Free Fatty Acids in Body FA travels through the bloodstream bound to albumin Contribute to energy requirements of exercise During moderate exercise, about 1/2 of the calories are from fat; after about 1 hour of exercise, there is a gradual increase in the use of fats for calories That is why we promote moderate exercise to reduce body weight Health effect of Total fats Heart diseases Cancer - animal fats Obesity - excess fat deposits in adipose tissues Fats 9  Diabetes - increase insulin resistant Fats deficiency - visual functions, brain functions are affected Health Effect of Different fat LDL (Low-Density Lipoprotein) increases the risk of heart disease (bad fats) HDL (High-Density Lipoprotein) scavenges cholesterol from the blood and LDL travels back to liver SFA (Saturated Fatty Acids) increases LDL levels and causes heart diseases. should get 10% energy from SFA Triglycerides - bad for the heart because high levels increase risk of stroke and heart disease Trans fats Increases LDL and reduce HDL Increased blood clotting risk insulin resistance (which leads to higher blood levels) Only 1% calories from trans fats are recommended Present in margarine (hydrogenated fats – hard margarine), fried foods, pizza, cakes, cookies, pastry How the diet should be planed …? Should not more than 35% of energy from fats Saturated fat intake should not higher than 10% of energy Fats 10  About 30g per men About 20 g per women 1:1.5:1 for SFAs/MUFAs/PUFAs Combinations of cooking oil Fats 11