Basics Of Nutrition PDF

Basics of Nutrition Dr. Dinusha Balasooriya Lecturer (Probationary)  Purpose Provide basic nutrition information, including food sources of nutrients, roles of nutrients in the body, and disorders associated with inadequate nutrition....

Basics of Nutrition Dr. Dinusha Balasooriya Lecturer (Probationary)  Purpose Provide basic nutrition information, including food sources of nutrients, roles of nutrients in the body, and disorders associated with inadequate nutrition. 2  Learning Objectives Understand the importance of nutrition. Identify food sources of nutrients. Describe the roles of nutrients in the body. Understand the causes and consequences of undernutrition. Describe strategies to combat undernutrition. 3  Nutrition Food = products eaten or taken into the body that contain nutrients for Development, growth, and maintenance of tissues and cells Resisting and fighting infection Producing energy, warmth, and movement Carrying out the body’s chemical functions 4  Essential Nutrients Macronutrients − Carbohydrates − Fats (lipids) − Proteins Micronutrients − Vitamins − Minerals Water 5  Macronutrients: Carbohydrates Best fuel – provide energy quickly and efficiently Two types Simple sugars Glucose (monosaccharide) – most common form Fructose (monosaccharide) – found in fruits Sucrose (disaccharide) – sources include granulated sugar, milk and milk products Complex carbohydrates (polysaccharides) Starches – from flour, pasta, potatoes – Stored in the body as glycogen Fiber 6  Food sources Grains, dairy products, fruits, legumes, starchy vegetables like potatoes. 7  Dietary fibre Dietary fibre which is mainly non-starch polysaccharide is a physiological important component of the diet. It is found in vegetables, fruits and grains. It may be divided broadly into cellulose and non-cellulose polysaccharides which include hemi-cellulose pectin, storage polysaccharides like inulin. These are all degraded to a greater of lesser extend by the micro flora in the human colon Uses? 8  Macronutrients: Fats and Oils (Lipids) Energy-giving foods Absorbed more slowly than carbohydrates Fats (solids): Butter, ghee, margarine Oils (liquids): coconut oil, Corn oil, soybean oil, peanut oil 9  Misunderstood but vital group of basic nutrients – Maintain healthy skin – Insulate body organs – Maintain body temperature – Promote healthy cell function – Carry fat-soluble vitamins A, D, E, and K – Are a concentrated form of energy 10  Avoiding trans fatty acids – Created by process of making liquid oil into a solid – Increase LDL levels while lowering HDL levels Higher risk of coronary and heart disease, sudden cardiac death – Found in many margarines, baked goods and restaurant deep-fried foods – Food labels listing no trans fasts can still contain less than 500 milligrams/serving 11  Essential fatty acids are those that cannot be synthesized by humans Dietary sources of EFA Linoleic acid (Omega 6) Sunflower oil, Corn oil, Soya bean oil, Sesame oil, Groundnut oil, Mustard oil, Palm oil, Coconut oil, nuts, seeds Linolenic acid (Omega 3) Soya bean oil, Leafy greens, fish oil 12  Macronutrients: Proteins Body-building foods Form main structural components of cells Help produce and maintain tissues and muscles Sources − Plants (e.g., beans, nuts, chickpeas) − Animals (meat, fish, dairy products, Egg) 13  Proteins are complex organic nitrogenous compounds. They also contain sulfur and some cases phosphorous and iron. Proteins are made of monomers called amino acids. There are about 20 different aminoacids which found in human body. Of this 9 are termed “essential” as they are not synthesized in human body and must be obtained from dietary protiens. (histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine) 14  Functions of Proteins Body building Repair and maintenance of body tissues Maintenance of osmotic pressure Synthesis of bioactive substances and other vital molecules 15  Manifestations of Protein-Energy Malnutrition (PEM) Marasmus: Severe growth failure – Weight < 60% weight for age – Emaciation, thinness, wrinkled skin, drawn-in face, possible extreme hunger Kwashiorkor: Severe PEM – Weight 60−80% weight for age – Swelling (edema), dry flaky skin, changes in skin and hair, appetite loss, lethargy Marasmic kwashiorkor: Most serious form of PEM, combining both conditions above − Weight < 60% weight for age 16  Micronutrients: Vitamins Organic compounds mostly from outside the body Do not provide energy Fat soluble: Dissolve in lipids, can be stored, not needed daily (e.g., vitamins A, D, E, K) Water soluble: Dissolve in water, absorbed into bloodstream immediately, needed daily Sources − Fruits − Dark leafy vegetables − Animal foods 17  Are complex organic substances Normal growth, maintenance, and reproduction Your body cannot produce all vitamins you can get those by eating a nutritious diet. Fat-soluble vitamins: carried in fatty parts of foods and dissolve in fats (body stores them in fat... build up can be dangerous) Water-soluble vitamins: dissolve in water (body does not store them) 18  Functions of Vitamin A It is responsible for normal vision. It contributes to the production of retinal pigments which are needed for vision lights. It is necessary for maintaining the integrity and the normal functioning of glandular and epithelial issue which lines intestinal , respiratory and urinary tracts as well as the skin and eyes. It supports growth, especially skeletal growth It may protect against some epithelial cancers such as bronchial cancers 19  Deficiency of vitamin A The signs of vitamin A deficiency are predominantly ocular. They are: Night blindness Conjunctival xerosis Bitot's spots Corneal xerosis Keratomalacia 20  VITAMIN D The nutritionally important forms of Vitamin D in man are Calciferol (Vitamin D2) and Cholecalciferol (Vitamin D3). Vitamin D is synthesized in skin using UV rays Available in liver, fish, egg, butter and milk 21  Functions of vitamin D and its metabolites Intestine: Promotes intestinal absorption of calcium and phosphorus Bone: Stimulates normal mineralization, Enhances bone reabsorption, Affects collagen maturation Kidney: Increases tubular reabsorption of phosphate 22  Deficiency of vitamin D Deficiency of vitamin D leads to: Rickets Osteomalacia Osteoporosis 23  Vitamin E Vitamin E is a fat-soluble vitamin with several forms, but alpha-tocopherol is the only one used by the human body. Its main role is to act as an antioxidant, scavenging loose electrons—so-called “free radicals”—that can damage cells. It also enhances immune function and prevents clots from forming in heart arteries 24  Vitamin E deficiency Retinopathy (damage to the retina of the eyes that can impair vision) Peripheral neuropathy (damage to the peripheral nerves, usually in the hands or feet, causing weakness or pain) Ataxia (loss of control of body movements) Decreased immune function Dry, flaky skin 25  Vitamin K Vitamin K helps to make various proteins that are needed for blood clotting and the building of bones. Prothrombin is a vitamin K-dependent protein directly involved with blood clotting. Osteocalcin is another protein that requires vitamin K to produce healthy bone tissue. 26  Vitamin K deficiency Increased clotting time Hemorrhage 27  Water-Soluble Vitamins Vitamin B-Complex Thiamin (vitamin B1) Riboflavin (vitamin B2) Niacin (nicotinamide, nicotinic acid, vitamin B3) Pantothenic acid (vitamin B5) pyridoxine (Vitamin B6) Biotin – vitamin B7 Folic acid – vitamin B9 Cobalamin- Vitamin B12 Vitamin C 28 Vitamins Dietary sources Daily dosage Deficiency Thiamin (vitamin B1) Rice, Peas, Beans, Adult- 1.5mg BeriBeri nuts, meat, eggs Infant-0.4mg Dry or neuritic Children -.4-1.2 mg Wet or oedematous Riboflavin (vitamin Green vegetables, Adult -1.5-1.8mg Angular stomatitis B2) Grains, peas, nuts Children- 1-1.8mg Inflammation of tongue Thickenng of skin Niacin (vitamin B3) Legumes, Fish, nuts, Adult- 10-20mg Pellagra coffee, tea (Dermatitis, Diarrhea, Dementia, Death 29 Pantothenic acid Egg yolk, cereals, Adult- 5-10mg Dermatitis, Loss of (Vitamin B5) legume, milk Children – 2-3mg hair, Fatty liver Pyridoxin Yeast, cereals, Adult-1-2mg Seizure Vitamin B6 grains, egg yolk Children- 0.6-1mg Biotin Vegetables, Adult- 100-200mcg Hair thinning Vitamin B7 milk,egg,meat,fish Infant-30-50mcg Skin rash, nail changes Folic acid Dark leafy Adult-400-500mcg Megaloblastic Vitamin B9 vegetables, dairy Children – 100- anemia products, egg, nuts 300mcg Pregnant & lactating 30 – 600mcg Cobalamin Liver,meat, Adult- 3mcg Megaloblastic vitaminB12 milk,cheese,eggs Children- 0.3mcg anemia, pernicious anemia Ascorbic acid Citrus fruits, Adult-75mg Scurvy Vitamin C papaya, tomato, Children-80mg Poor dentition of amla,green peas Pregnant and children lactating woman- Swollen spongy 100-150mg gums 31  Micronutrients: Minerals Inorganic compounds not synthesized by the body Needed in very small quantities but possibly essential Important for biochemical processes and formation of cells and tissues Sources − Plants − Animal products 32  In addition to vitamins your body also needs 15 minerals that help regulate cell function and provide structure for cells. Major minerals, in terms of amount present, include calcium, phosphorus, and magnesium. In addition, your body needs smaller amounts of chromium, copper, fluoride, iodine, iron, manganese, molybdenum, selenium, zinc, chloride, potassium and sodium. Amounts needed for most of these minerals is quite small and excessive amounts can be toxic to your body. 33  Calcium:A mineral important for strong teeth and bones and for muscle and nerve function. The major mineral constituent of bone. – sources: milk and milk products, fish with bones that are eaten, turnip and mustard greens, tofu, almonds and broccoli. Chloride: A mineral that regulates body fluid volume, concentration and acid-base balance. Balance intertwined with that of sodium Chromium: A mineral important in regulating blood glucose. sources: brewer's yeast, whole grains and meats Copper: A mineral that is important for nerve function, bone maintenance, growth, blood formation and utilization of glucose. – sources: organ meats, sea foods, nuts and seeds Fluoride: A mineral that is important to dental and bone health. Greatly improves resistance to cavitites – sources: fluoridated water, foods cooked in or containing fluoridated water, fish with bones that are eaten, and tea Phosphorus: A mineral essential to bone formation and maintenance, energy metabolism, nerve function and acid balance. – sources: meat, poultry, fish, eggs, dairy products and cereal products. Potassium: A mineral that is essential for nerve function, muscle contraction and maintenance of normal blood pressure. 34  Iodine: A mineral essential for the production of thyroid hormones. – sources: sea foods, iodized salt and foods containing iodized salt Iron: A mineral that is an essential constituent of blood and muscle and important for the transport of oxygen. Certain groups can be at risk of having low iron levels. These include young children and early teens, women with heavy menses, women with multiple pregnancies, and people with conditions that cause internal bleeding, such as ulcers or intestinal diseases. – sources: liver, red meat, egg yolk, legumes, whole or enriched grains and dark green vegetables. Magnesium: A mineral found mainly inside muscles, soft tissues and bone. It functions in many enzyme processes. – sources: nuts, legumes, whole grains and green vegetables 35  Selenium: A mineral associated with antioxidant properties and fat metabolism. It has been claimed to help prevent cancer and cardiovascular disease sources: seafoods and organ meats. Sodium: A mineral that regulates body fluid volume, concentration and acid-base sources: table salt (sodium chloride), foods processed with table salt, milk, milk products, eggs and seafoods Zinc: A mineral involved in wound healing, taste sensation, growth and sexual maturation and part of many enzymes regulating metabolism sources: meat, liver, eggs and seafood (oysters). 36  Water Main component of the body (60 percent of body mass) Needed for digestion, absorption, and other body functions Regularly lost through sweating, excretion, and breathing Approximately 1,000 ml (4−8 cups) needed each day 37  Nutritional Anemia Most common type of anemia Caused by malaria, hookworm, and inadequate iron and vitamin intake resulting in low hemoglobin levels Affects mainly children < 5 years old and pregnant women Detected by measuring blood hemoglobin levels 38  Effects of Anemia Adults – Reduced work capacity – Reduced mental capacity – Reduced immune competence – Poor pregnancy outcomes – Increased risk of maternal death Infants and children – Reduced cognitive development – Reduced immune competence – Reduced work capacity 39  Strategies to Prevent and Control Anemia Promote iron, folic acid, and B12-rich foods. Treat and prevent anemia-related diseases (malaria and worms). Provide iron and folic acid supplements to infants and pregnant and lactating women. Fortify foods. Promote vitamin C-rich foods with meals. Discourage drinking coffee or tea with meals. 40  Iodine Deficiency Disorders (IDD) Caused by inadequate intake of iodine Iodine in food sources varies by geography. – Less in highlands and mountain regions – Leached from soil and carried to lowlands 41  Manifestations of IDD Goiter: Enlarged neck region from overactive thyroid gland Hypothyroidism: Dry skin, weight gain, puffy face, lethargy from underactive thyroid Hyperthyroidism: Rapid pulse and weight loss from overactive thyroid Cretinism: Mental retardation, physical development problems, spasticity from IDD in mother during pregnancy 42  Strategies to Control IDD Iodize salt, dairy products, and bread where where iodine is deficient in local foods. 43  Undernutrition The manifestation of inadequate nutrition Common in sub-Saharan Africa – 1/3 of all children < 5 years old underweight – 38% of children with low height for age Many causes – Inadequate access to food/nutrients – Improper care of mothers and children – Limited health services – Unhealthy environment 44  Conditions Associated with Under- and Overnutrition Vitamin deficiency disorders – Scurvy (deficiency of vitamin C) – Rickets (deficiency of vitamin D) – Mental, adrenal disorders (deficiency of B vitamins) Mineral deficiency – Osteoporosis (deficiency of calcium) Diet-related non-communicable diseases – Diabetes – Coronary heart disease – Obesity – High blood pressure 45 Causes of Undernutrition 46  Strategies to Prevent and Control Undernutrition Improve household food security. Improve diversity of diet. Improve maternal nutrition and health care. Improve child feeding practices. Ensure child health care (immunization, medical care, growth monitoring). Provide nutrition rehabilitation. 47  Conclusions Good nutrition is essential for health and well-being. Daily well-balanced diets should include foods containing essential nutrients and meeting energy requirements. Inadequate nutrition can lead to PEM and vitamin and mineral deficiencies (anemia, VAD, IDD). Nutrition interventions include improved household food security, food fortification, vitamin and mineral supplementation (for women and children), and improved child feeding. 48