Introduction to Human Nutrition PDF

An-Najah National University Introduction to Human Nutrition Second Semester, 2023 Reference Book: Brown, J. and Lechtenberg, E. (2016). Nutrition through the life cycle. 6th ed. USA: Wadsworth publishing. Rolfes, R S. Pinna, K. and Whitney E. (2017) Nor...

An-Najah National University Introduction to Human Nutrition Second Semester, 2023 Reference Book: Brown, J. and Lechtenberg, E. (2016). Nutrition through the life cycle. 6th ed. USA: Wadsworth publishing. Rolfes, R S. Pinna, K. and Whitney E. (2017) Normal and clinical Nutrition. 11th Ed. USA: Cengage Learning. Dr. Nihal Natour Ms.Marah Shakhshir Main points Macros/Micros ( major contribution of each ) Micros – based on their solubility/ food sources only major) Eating disorders  Food affects almost everything we do. It affects how we look, feel, and act. It even affects our abilities – how well we function every day. Our Need Food has an impact on life because it supplies nutrients for Food Nutrients are chemical substances in food that the body uses for a variety of functions that support growth, tissue maintenance and repair, and ongoing health Principles of Human Nutrition Marah Shakhshir  Introducing Nutrients – Food is a mixture of chemicals – Essential chemicals = Nutrients – 6 categories of nutrients Carbohydrates Lipids (fats and oils) Proteins Vitamins Minerals Water  Describing Nutrients There are several ways to classify nutrients: – Organic/inorganic – Essential /nonessential – Macronutrient / micronutrient – Energy yielding /not energy yielding  Introducing nutrients Marah Shakhshir  Energy yielding Nutrients Macronutrient Energy Provision in average adult diet Carbohydrates 45-65% sugars and complex carbohydrates Fats 20-35% saturated and unsaturated fats Protein 10-35% provide essential and non-essential amino acids Marah Shakhshir  Understanding nutrients Carbohydrates Chemical substances in foods that consist of a Sugar and fruit, starchy vegetables, and single sugar molecule or multiples of sugar whole grain products are good dietary molecules in various forms. sources. Proteins Chemical substances in foods that are made up Animal products and dried beans are of chains of amino acids. examples of protein sources. Fats Components of food that are soluble in fat but Oil, butter, sausage, and avocado are not in water. They are more properly referred to examples of rich sources of dietary fats. as “lipids.” Most fats are composed of glycerol attached to three fatty acids. Vitamins Thirteen specific chemical substances that Vegetables, fruits, and grains are good perform specific functions in the body. Vitamins sources of vitamins are present in many foods and are essential components of the diet. Minerals In the context of nutrition, minerals consist of 15 Milk, dark, leafy vegetables, and meat are elements found in foods that perform particular good sources of minerals. functions in the body. Water An essential component of the diet provided by food and fluid. Marah shakhshir  Energy Balance Energy balance is the difference between energy intake(input) and expenditure (output) Human body requires energy to: – To perform its many functions, – To facilitate muscle activity and developmental demands – To correct problems that may have been caused by disease or injury.  Energy Balance How do we maintain or gain weight? Energy balance is achieved when the amount of energy intake = energy out Weight maintenance Positive energy balance: energy in> energy out which increased body weight Negative energy balance: energy in70) - Medium GI foods: they have moderate effect on Blood sugar (56-69) - Medium and Low GI foods are slowly broken down and cause a gradual increase in blood glucose (GI Rate: 0-55) High glycemic index Medium/ Low glycemic index Table Sugar (sucrose) Some fruits and vegetables White bread Whole grains Potatoes Pulses White rice Foods generally rich in fiber Marah Shakhshir  Fibers Fibers are complex carbohydrates (polysaccharides) and known as the storage form of energy in plants. They are found in all plant-derived foods fruits, vegetables, whole grains, and legumes. They are composed of many glucose atoms connected with bonds that cannot be broken down by digestive enzymes in the body Marah Shakhshir  Soluble Vs insoluble fibers They are sorted into two groups based on their solubility : soluble and insoluble Soluble Fiber Insoluble Fiber They dissolve in water and form gels in Do not dissolve in water, thus do not the gut form gel Easily digested by bacteria in the colon (fermentable) Found in : oats, citrus fruits, leguems. Found in: whole grains (bran), vegetables Most associated with protecting Most associated with promoting against heart disease, diabetes  by bowel movements, alleviate lowering cholesterol and blood constipation, and prevent diverticular gluocse disease Marah Shakhshir  Benefits of fibers Can help relief and reduce the risk of: Constipation,diverticulitis,haemorrhoids, appendicitis,varicose veins, diabetes, obesity (satiety related effects), cardiovascular disease, cancer of the large bowel and various other cancers. Humans need almost 20-35 gram per day or 12.5 g per 1000 Kcal  Lipids Like carbohydrates they are composed of Carbon, Hydrogen, and oxygen. Usually insoluble in water but soluble in organic solvents They include: Fatty Acids Triglycerides Phospholipids Sterols Marah Shakhshir  Lipids Fatty Acids (F.A): an organic acid, which is a chain of carbon atoms with hydrogens than has an acid group to one end and a methyl group at the other. They are classified based on the length of the carbon chain (up to 24 carbons) into: a) short chain (