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TOPIC 1. Introduction to Nutrition. INTRODUCTION TO NUTRITION.
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TOPIC 1 Introduction to Nutrition Hygiene&Nutrition FBH
INTRODUCTION TO NUTRITION • Nutrition is a science that studies nutrients in food and the body and their action, interaction and balance in relation to health and disease. Nutrition also examines the process by which an organism ingests, digests, absorbs, transports, utilizes and excretes food substances. Nutrition looks at how you select foods and the types of diet you eat. • Nutrient are the nourishing substances in food. They provide energy and promote body growth and maintenance. In addition, nutrients regulate the many body processes, such as heart rate and digestion, and support the body’s optimum health and growth. The six groups of nutrient are Hygiene&Nutrition FBH
Intro… • The first three nutrients, are called the energy-yielding nutrients, can be burned as fuel to provide energy for the body. The sequence of energy nutrients usage primarily from Carbohydrate, followed by lipids and as a last resort the body breaks down proteins into energy. • Vitamins, minerals and water cannot be used to provide energy. • Most, but not all, nutrients are considered essential nutrients. Essential nutrient either cannot be made in the body or cannot be made in the quantities needed by the body; therefore, we must obtain them through food. Carbohydrates, vitamins, minerals, water and some parts of lipids and proteins are considered essential Hygiene&Nutrition FBH
Classes of nutrients • There are 6 classes of nutrients: • Carbohydrate • Protein • Lipids (Fat & Oil) • Vitamins • Minerals and • Water Hygiene&Nutrition FBH
Macro & Micro Nutrients • Water, Carbohydrate, lipids and proteins are known as macronutrients in that these nutrients are found in large amounts in our bodies and our bodies require large quantities (over a few grams) of these nutrients daily • Vitamins, and minerals are known as micronutrients in that small amounts of these nutrient are found in our bodies and our bodies requires small quantities (mg or µg) of these nutrients on a daily basis. Hygiene&Nutrition FBH
Hunger, Appetite and Satiety • Hunger is the physiological need to eat. Hunger is influence by heredity. • Appetite is the psychological desire to eat. Appetite is a learned behavior and is influence by some of the sensory attributes of food – thinking about, seeing and smelling food. When there is ample food appetite triggers eating rather than hunger. • Satiety is the sense of feeling full. The hypothalamus helps regulate satiety. The hypothalamus responds to blood glucose concentrations as well as other factors such as amino acids and fatty acids in the blood and various hormones. Hygiene&Nutrition FBH
WHAT HAPPEN WHEN YOU EAT? • The gastrointestinal (GI) tract is like a hollow tube running through your body. • The top of the tube is your mouth, which connects in turn to your esophagus, stomach, small intestine, large intestine, rectum and anus. • In the mouth, food is ground by the teeth, chewed and mixed with saliva to make it easier to pass through the esophagus. • Peristalsis propels the food down the esophagus into the stomach and through the rest of the digestive tract. Hygiene&Nutrition FBH
The stomach, a muscular sack, holds about 1 litter of food. Within the folds of the stomach’s mucous lining are digestive glands that make hydrochloric acid and an enzyme to break down proteins. Hydrochloric acid aids in protein digestion. • The stomach churns the food to the liquid consistency of chyme. • The duodenum of the small intestine receives the digested food from the stomach as well as pass through the villi of the duodenum and jejunum into either the blood or lymph vessels. • The large intestine stores the waste products of digestion and absorbed water and some minerals. Hygiene&Nutrition FBH
The Gastrointestinal Track Hygiene&Nutrition FBH
The Villi & Red blood Cells Hygiene&Nutrition FBH
DIGESTION, ABSORPTION AND METABOLISM • DIGESTION is the process by which food is broken down into its components in the mouth, stomach and small intestine with the help of digestive enzymes. • Complex proteins are digested, or broken down, into their building blocks, called amino acids; complicated sugars are reduced into simple sugar such as glucose; and fat molecules are broken down into fatty acids. Hygiene&Nutrition FBH
Before the body can use any nutrients present in food, they must pass through the walls of the stomach or intestines into the body’s tissues, a process called ABSORPTION. • Nutrients are absorbed into either the blood or the lymph, two fluids that circulate throughout the body delivering needed products to the cells and picking up wastes. • Blood is composed mostly of blood cells (which carry and deliver oxygen to the cell), white blood cells (which are important in resistance to disease, called immunity), nutrients and other components. • Lymph is similar to blood but has not red blood cells. It travels to areas where there are no blood vessels to feed the cells. Hygiene&Nutrition FBH
Within each cell, METABOLISM takes place. Metabolism refers to all the chemical processes by which nutrients are used to support life. • Metabolism has two functions: the building up of substances (called anabolism), and the breaking down of substances (called catabolism). • Within each cell, nutrients such as glucose are split into smaller units in a catabolic reaction that releases energy. • The energy is either converted to heat to maintain body temperature or used to perform work within the cell. • During anabolism, substances such as protein are built from their amino acid building block. Hygiene&Nutrition FBH
Body circulation and Cells Hygiene&Nutrition FBH
TOPIC 2 CARBOHYDRATE Hygiene&Nutrition FBH
CARBOHYDRATE Carbohydrate literally means hydrate (water) of carbon. Later chemical analysis of sugar & other carbohydrate indicated that they all contain at least carbon, hydrogen and oxygen. • Carbohydrates are the major components of most plants, making up from 60 to 90 percent of their dry weight. In contrast, animals and humans contain a comparatively small amount of carbohydrates. • Plants are able to make their own carbohydrate from carbon dioxide in air and water taken from the soil in a process known as photosynthesis. • This is the process where the energy from the sunlight is converted into energy stored carbohydrate. Animal are incapable of photosynthesis and therefore, depends on plants as a source of carbohydrate. Hygiene&Nutrition FBH
FUNCTIONS OF CHO • Carbohydrates are the primary source of body’s energy. In fact, the central nervous system, including the brain and nerve cell, relies almost exclusively on glucose for energy. • If there is not enough carbohydrate for energy, the body can burn either fat or protein, but this is not desirable. • When fat is burned for energy without any carbohydrate present, the process is incomplete and the results in the production of catone bodies, which starts to accumulate in the blood. An excessive level of catone bodies can cause the blood to become too acidic (called catosis), which then interferes with the transport of oxygen in the blood. Ketosis can cause dehydration and may lead to a fatal coma. Hygiene&Nutrition FBH
FUNCTIONS OF CHO • Carbohydrates are important to help the body use fat efficiently. Carbohydrates also spare protein from being burned for energy so protein can be better used to build and repair the body. • About 100 grams of carbohydrates are needed daily to spare protein from being burned for fuel, to prevent ketosis and to provide glucose to the central nervous systems. Hygiene&Nutrition FBH
CLASSIFICATION & SOURCES • Carbohydrates are separated into two categories: simple and complex. Simple carbohydrate, also called sugars, included both natural and refined sugars. • Carbohydrate are much more than just sugars, it includes complex carbohydrate such as starch and fiber. • Another name for complex carbohydrate is polysaccharide (poly means many), a good name for starch and fiber because both are long chains of many sugars. Hygiene&Nutrition FBH
Sugars. Simple carbohydrate includes monosaccharides, or single sugars and disaccharides or double sugars. The term sugar refers to both collectively • Monosaccharides includes simple sugars such as Glucose, Fructose and Galactose, which are the building blocks of other carbohydrate such as disaccharides and starches. • Disaccharides the double sugars includes Sucrose, Maltose, and Lactose. • Starch, is made of many chains of hundreds to thousands of links glucoses (Polysaccharides). Hygiene&Nutrition FBH
CHO in the Body • The human body store glucose in a form called glycogen. The chain may be straight or may have tree-like branches. • The body stores glycogen in the liver and muscles. An active 150 pound man has about 350 calories stored in his liver glycogen and about 1400 calories stored in his muscle glycogen. • When the blood sugar level starts to dip and more energy is needed, the liver convert the glycogen into glucose, which is then delivered by the bloodstream. Muscle glycogen does not supply glucose to the bloodstream but is used strictly to supply energy for exercise. • Glycogen is important to maintain normal blood sugar level. • Starches are found in cereal grains, breads, baked goods, cereals, pastas, root vegetables and dried beans and peas. They are commonly used as thickeners through the process of gelatinization when heated with liquid. Hygiene&Nutrition FBH
DIETARY FIBER • Dietary fiber is mostly material from plant cell walls that resists digestion by our digestive enzymes. In other words, most fiber passes through the stomach and intestines unchanged and is excreted in the feces. Fiber is found in plant foods; it does not appear in animal foods. There are two major types of fiber; water-soluble and water-insoluble. • Water-soluble fiber swells in water, like sponge, into a gel-like substance. They are generally found around and inside plant cells. • Water-insoluble fiber also swell in water, but not nearly to the extent as the soluble fiber. They generally form the structural part of plants. • Fiber is abundant in plants, such as legumes (Dried bean, peas, and lentils), fruits, vegetables, whole grains and grain products, nuts and seeds provide fiber. Fiber is not found in meat, poultry, fish, dairy products and eggs. • Water-soluble fibers tend to decrease blood cholesterol levels and delay stomach emptying. • Water-insoluble fibers makes stool easier to eliminate and may reduce the risk of colon cancer. Fiber-rice foods also help diabetics maintain normal blood sugar level. Hygiene&Nutrition FBH
DIGESTION, ABSORPTION & METABOLISM • Before carbohydrate can be absorbed through the wall of the small intestine, they must be broken down into monosaccharides, or one-sugar units. • Starch digestion begins in the mouth, where the enzymes start to break down starch into polysaccharides and oligosaccharides (a chain of 4 to 10 glucose units). • Then the intestine completes the breakdown of starch into maltose, which split by an enzyme into 2 glucose unites. Glucose is then absorbed. • Through the work of various enzymes, all sugars are broken down into single sugars: glucose, fructose and galactose. • They are absorbed and enter the bloodstream, which carries them to the tissues and the liver. In the liver, fructose and glalactose are converted to glucose or further metabolized. • The hormone insulin makes it possible for glucose to enter body cells, where it is used for energy or stored as glycogen. Hygiene&Nutrition FBH
Carbohydrate digestion chart Hygiene&Nutrition FBH
EXCESS & DEFICIENCY • Most of the time excess of carbohydrate can cause tooth decay. Without good tooth brushing habits, plague may cover all surface of the teeth. • Diabetes is not cause by sugars. Diabetes is a disorder in the way the body handles sugars. People with diabetes do not make enough insulin, or they cannot use the insulin their bodies do make. Insulin gets sugar from the bloodstream into the body’s cell, where sugar is used to produce energy. Therefore, untreated diabetes have high blood sugar levels. • Hypoglycemia is the opposite of high blood sugar level in the body. It is refers to as both low blood sugar and to diseases that cause low blood sugar. • There are basically two types of hypoglycemia: Postprandial hypoglycemia and fasting hypoglycemia. The most common is the postprandial hypoglycemia, which occurs generally 1 to 4 hours after a meal .It may be cause when a rapid rise in blood glucose after a meal cause a temporary overproduction of insulin, which pulls too much sugar out of the bloodstream. Hygiene&Nutrition FBH
EXCESS & DEFICIENCY • Lactose Intolerance. Lactose (milk sugar) is a problem for people who lack, or more commonly, don’t have enough of the enzyme lactase needed to split lactose, if lactose is not split, it travels to the colon where the bacteria ferment it and produce short-chain fatty acids and gas. This problem, called lactose intolerance, seem to be an inherited problems especially among African, Greeks and Asians, as well as other population groups. • Obesity is not the cause by sugars intake alone. Obesity is cause by fat that is usually team up with sugar. • Excess intake of Fiber in the diet can also lead to slow absorption of Calcium, Zinc and copper. Hygiene&Nutrition FBH
Shapes of CHO i. MONOSACCHARIDES ii. DISACCHARIDES GLUCOSE GLU F SUCROSE = TABLE SUGAR GALACTOSE GLU GLU MALTOSE FRUCTOSE GLU GAL LACTOSE Hygiene&Nutrition FBH
iii. OLIGOSACCHARIDES Consist of 3 to 4 chains GLU GLU GLU GLU GLU F GAL iv. POLYSACCHARIDES Consist of many monosaccharides or can also be called as starches with 100 to 2000 monosaccharides GLU GLU GLU GLU GLU GLU Hygiene&Nutrition FBH
C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C • Starches • Can be divided into two categories • AMYLOSE • AMYLOPECTIN Hygiene&Nutrition FBH
TOPIC 3 PROTEIN Hygiene&Nutrition FBH
PROTEIN - Introduction FUNCTIONS • The many functions of protein are as follows; Acts as a structural component of the body • Protein can be found in skin, hair, fingernails, muscles, blood vessels, the digestive tract and blood. It appears in every cells as part of deoxyribonucleic acid (DNA), which carries the genetic code. Builds and maintains the body • Protein are used for building and maintaining body tissues. Worn-out cells are replaced throughout the body in regular intervals. It is constantly being broken down and rebuilt or remodeled, as are most body cells, including the protein within the cells. • The greatest amount of protein is needed when the body is building rapidly, such as during pregnancy or infancy. Additional protein is also needed when body protein is either lost or destroyed as in burns, surgery or infections. Hygiene&Nutrition FBH
Found in many enzymes, hormones and antibodies • Protein is found in many enzymes, hormones and antibodies. Thousand of enzymes have been identified. Almost all the reactions that occur in the body such as food digestion, involve enzymes. • Enzymes are catalysts, meaning that they increase the rate of these reactions, sometimes more than a million times. They do this without being changed in the process. Enzymes contain special pocket called the active site. This pocket site, act as a lock which only a correct key will fit. Various substances will fit this pocket and will be transform through a chemical reaction to a new form, leaving the enzymes to speed up other reactions. • Hormones are chemical messengers secreted into bloodstream by various organs, such as liver to regulate certain body activity. • Antibodies are blood protein whose job is to bind with foreign bodies or invaders that do not belong in the body. Invaders could be a virus, bacteria or toxins. Each antibody fights a specific invader. Hygiene&Nutrition FBH
Transport irons, fats, minerals and oxygen • Protein also acts as a transporter for iron, fats, minerals and oxygen in the body. Maintains fluids and acid-base balance • This means to maintain the body fluid and the acid-base balance of the blood. The blood must remain neutral; otherwise dangerous conditions knows as acidosis or alkalosis can occur. Some blood protein have the chemical ability to buffer or neutralize both acids and bases. Provides energy as last resort • In addition, amino acids can be burned to supply energy id absolutely needed. Of course, burning takes them away from their vital functions, but some amino acids can be converted to glucose and burned. Hygiene&Nutrition FBH
CLASSIFICATION • Protein contains carbon, hydrogen and oxygen, and the most important of all is that it contains nitrogen. Nitrogen is necessary for the bodily functions, life as we know it wouldn’t exist without nitrogen. • Proteins are long chains of amino acids strung together much like railroad cars. Amino acid is the building block of protein. There are 20 different ones each consisting of a backbone to which a side chains is attached. The amino acid backbone is the same for all amino acids, but the side chain varies. It is the side chain that makes each amino acid unique. • There are 20 amino acids in proteins, nine either cannot be made in the body or cannot be made in the quantity needed. They must therefore be obtained in foods for the body to function properly. This is why we call these amino acids essential or indispensable amino acids. The remaining 11 can be made in the body. Hygiene&Nutrition FBH
When the amino acids backbones join end to end, a protein forms. The bonds that form between adjoining amino acids are called peptide bonds. Protein often contains 35 to several hundred or more amino acids. • Protein fragments with 10 or more acids are called polypeptides. • Each of the over 100,000 different protein in the body contains its own unique number and sequence of amino acids. In other words, each protein differs in term of what amino acids it contains, how many it contains and the order in which they are contained. • The number and sequence of the amino acids in the protein chain is called the primarystructure. Hygiene&Nutrition FBH
After a protein chain has been made in the body, it does not remain a straight chain. • In the instant after a new protein is created, the side chain of each amino acid in the strand either attracts or repels other side chains, resulting in the protein either bending or coiling. This bending and coiling is called the protein’s secondary structure. • One more step must take place before the protein can do any work in the body. Due in part to the interaction of amino acids at some distance from each other in the chain, the protein folds and loops. • This process of folding resulting in the protein’s tertiary structure. A protein tertiary structure – how it bends and fold - makes the protein able to perform its functions in the body. Hygiene&Nutrition FBH
Denaturation. • Under certain circumstances, a protein’s shape is distorted, causing it to lose its ability to function. In most cases, the damage cannot be reversed. Denaturation can occur both to protein in food and to proteins in our body. • Denaturation can be caused by high temperatures (as in cooking), ultraviolet radiation, acids and bases, agitation or whipping, high salt concentration and the salt of mercury, silver and lead. Hygiene&Nutrition FBH
SOURCES • Protein is found in animal and plant food. Protein is highest in animal food, such as beef, chicken and fish. • The amount of protein in one serving of many milk and dairy products is about the same as in one serving of many grains and legumes (dried bean and peas). • Of the plant foods, grains, legumes and nuts usually contribute more protein than vegetables and fruits. • Protein-rich foods are usually higher in fat and saturated fat and always higher in cholesterol, than plant foods (plant food have no cholesterol). Hygiene&Nutrition FBH
PROTEIN QUALITY • To understand the concept of protein quality, you need to recall that nine of the 20 amino acids either can’t be made in the body or can’t be made in sufficient quantity. • Complete Protein food are foods that provides all the essential amino acids in the proportions needed. These food includes animal protein, such as meat, poultry, fish, eggs, milk and other dairy products. • Lowest concentration of amino acids in protein is referred to as a limitating amino acids. • Incomplete protein contains at least one limiting amino acid. Plant proteins, including dried beans and peas, grains, vegetables, nuts and seeds is incomplete. • Complementary Protein is when a combination of incomplete protein and limitating amino acids are eaten over the course of the day. Hygiene&Nutrition FBH
Protein Allowance • is base on the size of the body itself. Normally 0.8g to per kg of the body weight. • Laborer & athletes needs increase of protein requirement. • Elderly & people of advancing ages, maintain normal requirement & still base on body weight. Hygiene&Nutrition FBH
DIGESTION, ABSORPTION & METABOLISM • Digestion of protein is aim to break down protein into amino acids. The amino acids in food proteins are of little value in nutrition until they pass from the stomach into the blood stream, so digestion of protein is crucial. • Protein is digested in the stomach by an enzyme called pepsin, a protein by itself. In this process the long chain of polypeptides in protein are broken down or hydrolyze into individual amino acids. Hygiene&Nutrition FBH
Absorption • After the protein has been hydrolyze into amino acid form, only then the absorption process begins. • In milk & eggs absorption of protein is 97% • Meat & poultry the absorption is less than 97%. For plants’ protein the absorption is between 75% to 85%. • Individual amino acids are pass through the intestinal wall and absorbed into the bloodstream. From the blood stream it is transported through blood circulation to the tissues for growth, repair & possibly use as an energy source on a low fat or low carbohydrate diet. This is called as (Active transport energy) of protein. Because the protein are used directly from the bloodstream without being hydrolyzed from the body’s storage. Hygiene&Nutrition FBH
Metabolism • In the blood circulation has all kinds of amino acid and this can be called as amino acid pool. • The amino acids are carried by the circulation first to the liver and then around the tissues in the body. • In these tissues amino acids are built up again into proteins to form the many different proteins making up the human body. Hygiene&Nutrition FBH
Nitrogen Balance • Some amino acid are also used for energy, so they can no longer take part in this dynamic building process and they are broken down so that their nitrogen content is eventually lost in urine and sweat as urea. • In healthy adult, the two process of anabolic and catabolism, protein nitrogen gain and its loss are balanced. In growing children, more protein nitrogen is eaten then is lost, this is called as positive nitrogen balance. The excess is used to built muscles and connective tissue protein. • In starvation, body proteins are gradually depleted causing a condition of negative balance. Other times of increase need for protein are by increase in weight, heavy training in athletes, pregnancy, breastfeeding and after injury. Hygiene&Nutrition FBH
Anabolic • From the amino acid pool, the amino acid are picked up by the body cells for the synthesis of protein required by each cells. • The synthesis of amino acid needs hormones .The liver is the main organ that regulates the metabolism of amino acids. • When amino acids are used to built new tissues it is called as the POSITIVE NITROGEN BALANCE. • Children for growth • Restoration of body tissues after illness or injuries • Pregnancy and breastfeeding (lactating) Catabolism • The process also involves the liver organ. The amino acids will be taken from groups of the amino acids pool to be used as energy during starvation. The urea is the principle of Nitrogenous waste products in urine. • Tissue breakdown is more then of tissue maintain or repair is called as a state of NEGATIVE NITROGEN BALANCE. Hygiene&Nutrition FBH
This state of negative nitrogen balance happen if:- • inadequate amount of protein in the diet • poor quality of protein • inadequate calories intake means low protein • faulty absorption from the intestinal track • due to excessive secretion of thyroid hormones • insulin deficiency • The excess of protein will be directed into the following channel • Intestinal Track to feces • Blood to liver to kidney to Urine Hygiene&Nutrition FBH
Muscles Tissue • Muscle tissue consist the following: • Water = ¾ of the weight of muscles • Protein = 18%, Fat = 4-10%, CHO (Glycogen & Glucose) = 1% • Protein in muscle • Myosion, actin & tropomyosin • Myosion + actin = actomyosin. This is the principle action during contraction of muscles. • actomyom is the state when myosion & actin releases and achieved relaxation of muscles Hygiene&Nutrition FBH
Protein and Health • Eating too much high-fat animal protein can increase your blood cholesterol levels, increase calcium loss from the body (worsen when intake is low), and worsen kidney problems in people with renal disease. • Eating too much high-fat animal protein can raise your blood cholesterol levels, which in turn increase your risk of cardiovascular disease. • By eating fewer plants proteins, you are also missing out on good sources of fibers and antioxidant nutrients, which may protect against cancer. Hygiene&Nutrition FBH
On the other hand eating too little protein can cause problems too, such as slowing down the protein rebuilding and repairing process and weakening the immune system. Protein-energy malnutrition (PEM refers to a broad spectrum of malnutrition from mild to serious cases. PEM can occur in infants, children, adolescents and adults but it is generally occurs in infants and children. PEM develops gradually over weeks or months. In mild cases of PEM, there is weight loss, stunted or slow growth, and more sedentary behavior. Hygiene&Nutrition FBH