Nutrition 120 PDF

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Nutrition 120 PG 2-15 - Nutrition: science that deals with all interactions that occur between living organisms and food. - Food provides nutrients and energy, which are required to keep us alive and healthy and support growth. - We prefer to eat food that is conveniently available, even though it might be adding to our waistlines. - A study stated that Canadians do not eat the recommended servings of food and are always under -eating the portion of each required nutrient. - An unhealthy dietary pattern along with the lack of physical activity increases the risk of obesity and chronic diseases. Top 3 leading causes of death in Canadians are nutrition-related.(cancer, heart disease, stroke) Essential nutrients: must be supplied by the diet to support life. They either cannot be made by the bodies or are produced in insufficient quantities. Vitamin C is an essential vitamin. Fortified Foods: The foods to which nutrients have been added during processing. The type and amount of nutrients added can be regulated and are intended to restore nutrient losses caused by processing of food.

Natural Health Products: Category of products regulated by Health Canada that includes vitamin and mineral supplements, amino acids, fatty acids, herbal remedies. They occupy a middle ground between food and drugs. About 40% Canadians use vitamin and mineral supplements. Food contains substances that are needed by the body but are not essential in diet. e.g. Lecithin- substance found in egg yolks is needed for nerve function. Phytochemicals: Substances in plant foods that are not essential but might have health promoting properties. Zoochemical : Substances that are found in animal foods that are not essential but might have health-promoting properties. e.g. certain fatty acids In fish oils are examples of zoo-chemicals and are linked to reduced risk of cardiovascular diseases.

There are 6 classes of nutrients: 1. Carbohydrates Macronutrients 2. Fats 3. Proteins 4. Minerals micronutrients 5. Vitamins 6. Dietary fibre 7. water Energy-yielding nutrients: Nutrients that can be metabolized to provide energy. Organic molecule: Those contain carbon bonded to hydrogen. Inorganic molecule: Those substances that contain no carbon-hydrogen bonds. Kcal : unit of heat used to express amount of energy provided by foods. Kilojoule : Amount of work required to move an object of one kilogram a distance of one meter under the force of gravity. (4.18 kJ = I Kcal) Macronutrients: Nutrients needed by body in large amounts. Include water, lipids, carbohydrates, proteins, energy yielding nutrients, etc.

1. CARBS: contain 4 kcal energy per gram. Fibre is also a carbohydrate but it doesn't provide enough energy. Most fibre is very important for gastro-intestinal health. It is found in legumes(peas, peanuts, beans and lentils), vegetables and whole grains. 2. LIPIDS: provide 9kcal per gram Triglycerides is the most abundant form of lipids in our body. Even the outer layer of our skin is composed of triglycerides Triglycerides are made up of 3 fatty acids. Diets high in saturated fatty acids increase the risk of heart diseases whereas monounsaturated and polyunsaturated may reduce those risks 3. PROTEIN: maintenance and growth of body structures. (4kcal per gram) Sources: Fish, poultry, eggs, vegetables and legumes. WATER: macronutrient that does not provide energy. Serves functions such as acting as a lubricant, transport fluid and a regulator of body temperature. Micronutrients: Nutrients needed by body in small amounts. e.g. vitamins and minerals. • VITAMINS: Organic molecules that do not provide energy but are required to regulate body processes. There are 13 vitamins. Help in bone growth, vision, blood clotting, etc. • MINERALS: they are inorganic molecules and they do not provide energy We need them for bone strength, oxygen transport and transmission of nerve impulses. NUTRIENT FUNCTIONS Providing Energy - Biochemical reactions release the energy stored in carbohydrates, lipids and proteins -> some of this energy is used to main bodily functions and some of it is used to synthesize new products.

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calorie = calorie Calories = kilocalorie

- When this energy is not consumed immediately, it is stored as fats. These fats provide energy when dietary sources are unavailable. - If more energy is consumed than needed, body weight increases. - If less energy is consumed than needed, the weight will decrease. Forming structures - Most weight of human body is due to water(62%), protein(16%) and fats(16%). Other is 6%minerals, carbs, and other substances. - Proteins form ligaments and tendons that hold bones together and attach muscles to bones. - Proteins form framework of bones that is hardened by mineral deposits. - Lipids and proteins make up the membranes that surround cells. Regulating body processes - Metabolism: the sum of all chemical reactions that occur in our body are referred to as metabolism. - Homeostasis: A physiological state in which stable internal body environment is maintained is known as homeostasis. - The enzymes that catalyze the reactions of metabolism are made up of proteins. - Water is the solvent for metabolism; therefore, all reactions occur in watery component of cells. NUTRITION AND HEALTH

Malnutrition: any condition resulting from an energy or nutrient intake either above or below to what is optimal. It includes both undernutrition and overnutrition. Undernutrition: Form of malnutrition caused by deficiency of nutrients or energy. Can be caused by deficient intake, increased requirements or inability to absorb or use nutrients. STARVATION: deficiency of energy that causes weight loss, poor growth and the inability to reproduce and if severe enough, death. Vitamin B12 is needed for normal nerve functioning. It's absorption decreases with age. Overnutrition: When excess of specific nutrients is consumed, an adverse or toxic reaction may occur. e.g. excessive dose of iron can cause liver failure. Food toxicity is generally dur to higher intake of vitamin and mineral supplements. Foods are not that concentrated to cause toxicity in one's body. In Canadian population, about 60% of adults are obese or overweight. DIET-GENE INTERACTIONS Genes: units of DNA that are responsible for inherited traits. They also determine your risk in developing certain chronic diseases. Nutrigenomics: study of how diet effects our genes and how individual genetic variation can affect the impact of nutrients or other food components on health. Personalized nutrition : The idea of diet based on genes that an individual has inherited can be used to prevent, moderate or cure chronic diseases. FACTORS AFFECTING OUR FOOD CHOICES Availability: It is affected by the 1. Geography: dietary choices are often limited to food choices available in the local market(in some underdeveloped countries) 2. Socio-economics: even if foods are available to all the folks, not everyone can afford nutritious foods. Low income individuals are therefore, limited to low priced foods only. 3. Health status: people with food allergies and digestive problems have very limited foods to make choices from. Cultural and Family Background: some foods that are considered nutritious by some cultures can be considered contaminants by the other culture. Also some foods are eaten on traditional occasions in one culture and are prohibited in other culture. Social Acceptability: food is the centrepiece of everyday interactions. Social events dictate our food choices, enabling us to make more polite decisions such as even eating foods that we don’t like. Personal Preference: our own preferences for food, not eating a food just coz u don’t like it. Psychological and Emotional Factors: some foods make us feel better in certain situations such as soups can be related to sickness. Health Concerns: An individual's perception of what makes a healthy diet affects their food choices. A recent survey stated that 50% Canadians were making diets better by reducing fats , sugar and salt and increasing vegetable and whole grains consumption. CHOOSING HEALTHY DIET Adequacy: State in which there is sufficient amount of a nutrient or nutrients in the diet to maintain health. Nutrient density: An evaluation of nutrient content in a food in comparison to the kcal it carries. e.g. broccoli is more nutrient dense than French fries. Eat a variety of foods: variety ensures that we get all necessary nutrients because no one food contains all nutrients. Balance your choices: Involves mixing all types of food so as to get adequate nutrients. A balanced diet gives required amounts of vitamins and minerals and not exceeding amounts that might harm your health. Everything in moderation: it means everything is good, as long as you don’t do it in excess. - Portion distortion: the increase in portion size for typical restaurant and snack foods, observed over 40 years. Kcalorie control: specific aspects of balance and moderation that are relatively related to energy intake.

PG 35-53 Nutrient Recommendations Nutrient based approach: amount of individual nutrients that are needed Food based approach: a dietary pattern is recommended - A dietary pattern describes the amounts and types of foods to eat to ensure an adequate intake of all nutrients. - Dietary Reference Intake: Set of reference values for intake of energy, nutrients and food components that can be used for planning and assessing the diets of healthy people of the country.

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- Designed to promote health and prevent nutrient deficiencies. Fat soluble vitamins: Vitamin A,D,E and K. Water soluble vitamins: Vitamin B and C and minerals such as calcium, phosphorous magnesium, fluoride.

○ Life stage groups: grouping of individuals based on stages of growth and development, pregnancy and lactation, that have similar nutritional needs. ○ Criterion of adequacy: functional indicator such as levels of nutrient in the blood, that can be measured to determine the biological effect of level of nutrient intake. e.g. testing blood or urine to check how that drug worked or how much is stored in body and how much is excreted. SETS OF REFERENCE VALUES >> The AI and RDA are used to set goals for individual intake and can be used to plan or evaluate individual diets. ○ RDA: Recommended dietary allowance. Intakes that are sufficient to meet the nutrient needs of almost all healthy people in a specific life stage and gender group. ○ AI :Adequate Intakes. These are established when there is inadequate data to set an EAR or calculate RDA. AI refers to the Intakes that should be used as a goal when no RDA exists. Approximation of average nutrient intake that appears to sustain desired Indicator of health. Cannot be used to calculate probabilities of adequacy. ○ Probability of inadequate intake is lowest if intake equals RDA, and increases more the intake falls below RDA ○ UL: Tolerable upper intake levels. Maximum daily intakes that are unlikely to pose a risk of adverse health effects to almost all individuals in a specified age and gender group. The UL helps prevent nutrient toxicities. It's a guide for limiting intakes. ○ EAR: Estimated average requirements. Average amount of nutrient required for health. Intakes that meet the estimated nutrient needs of 50% of the individuals of same sex life-stage group. EAR is used to determine RDA and evaluate adequacy of nutrient intakes for populations ○ Saturation of the blood : As someone's intake of a specific vitamin increases, the blood level of that vitamin increases to a certain point and then levels off. After this saturation point has been achieved, all the amounts of that vitamin that you will consume afterwards will excrete. They measure the amount of this vitamin in waste and the amount taken by that person. This information is helpful in determining what is the requirement for that vitamin. ○ If an individual has an intake according to EAR then there is 50% probability that he is meeting his requirement. ○ Depletion-repletion experiment: (read pg.38 bottom) ○ No two people will have the same requirement for any particular nutrient or vitamin, as tested by the depletion-repletion experiments ○ Requirement distribution: plot of nutrient requirements for a group of individuals in the same life stage. The shape of this distribution is usually normal distribution. ○ Ear cut point method: A method that indicates the proportion of the population that is not meeting its requirements, indicated by proportion of population that's under EAR. ○ Intake distribution: Plot of the intakes of a specific nutrient in a population. It's usually normal distribution. ○ (EER)Estimated energy requirements: average energy intake predicted to maintain body weight in healthy individuals. These are the recommendation for the energy intake or kilocalories intake. ○ (AMDR)Acceptable macronutrient distribution ranges: ranges of intake, for energy yielding nutrient, expressed as a percentage of total energy intake --> linked with low rates of chronic diseases and providing adequate intake of essential nutrients. ○ Acc. To RDA, healthy diet should be around be - 45-65% kcal from carbs - 20-35% from fats. - 10-35% from protein. ○ DRI's can be used to plan diets as well as standard for meals prepared at schools or hospitals ○ 4 food groups; - Vegetables and fruits - Meat and alternatives - Milk and alternatives - Grain products ○ The length of arc corresponds to the number of food servings recommended in each food group. ○ Veg. and fruits- Vitamin A and C, folate, potassium ○ Grain products: iron , fibre, B vitamins, magnesium ○ Milk and alternatives: calcium, vitamin D ○ Meat and alternatives: iron, zinc and some B vitamins(B12) ○ The target of food guide is to meet requirements of at least 90% of the population ○ Choosemyplate.gov = Americans ○ Korea and China = pagoda shaped food guide ○ Mediterranean diet = pyramid

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Used for testing purposes

Organ systems and functions January 27, 2018

1. 2. 3. 4. 5. 6. 7. 8. 9. 10.

7:47 PM

Cells of similar structure and function are organized into tissue There are 4 types of tissues: muscles, nerve, epithelial and connective. Organs work with cooperation to form organ systems. Organs: discrete structures made up of more than one tissue that perform specialized function. Stomach contains all four types of tissue ORGAN SYSTEMS: Nervous system Respiratory system- lungs Urinary system- kidneys and bladder Reproductive system Cardiovascular system- heart and blood vessels Lymphatic/immune system Muscular system Endocrine system- hormones Integumentary system- skin and body linings Digestive system

- Pancreas is a part of both endocrine as well as digestive system. Organ system

What it includes

What it does

Nervous

Brain, spinal cord, associated nerves

-Responds to stimuli -Conducts impulses to activate muscles and glands -Integrates activities of other systems

Respiratory

Lungs, trachea and air passageways

-Supplies the blood with oxygen and removes carbon dioxide

Urinary

Kidneys and associate structures

Eliminates waste and regulates the balance of water, electrolytes, and acid in the blood

reproductive

Testis, ovaries

Produces offspring

cardiovascular

Heart and blood vessels

Transports blood, which carries oxygen, nutrients and waste

Lymphatic/immune

Lymph and structures, white blood cells

-Defends against foreign invaders -Picks up fluid leaked from blood vessels -Transports fat-soluble nutrients

Skeletal muscles

Provides nutrients and structure

skeletal

joints

-Protects and supports the body -Provides framework for muscles to use for movement

endocrine

Pituitary, adrenal, thyroid and other ductless Secretes hormones that regulate processes such as glands growth, reproduction, and nutrient use

integumentary

Skin, nails, hair and sweat glands.

Covers and protects the body; helps control body temperature

digestive

Mouth, pharynx, oesophagus, stomach, small intestine, large intestine, liver, and gal bladder

Ingests and digests food; absorbs nutrients into the blood; eliminate the unabsorbed food residue

The food we eat, e.g. the whole wheat bread, is broken into carbs, protein and fat. The carbohydrate --> sugars Proteins --> amino acids Fats --> fatty acids - Fibre is not digested, therefore passed out as waste. STRUCTURE OF GASTROINTESTINAL TRACT( gut, digestive tract or alimentary canal) - Part of the digestive system - About 10 m in length - Runs from mouth to anus - Mouth, pharynx, esophagus, stomach, intestines and anus - Inside of the tube that these organs form is called lumen - The food in lumen is actually still outside the body - Only after absorption, when the food goes to cells, the food is technically inside the body Digestion : The process of breaking food into components small enough to be absorbed into the body. Absorption: the process of taking substances into your body. Feces: body waste including unabsorbed food residue, bacteria, mucus, etc. GI Tract: hollow tube consisting of mouth, pharynx, stomach , intestines, and anus. Mucosa: the layer of tissue lining the GI tract and other body cavities. Transit time: the time required by food to pass the GI tract from mouth to anus(24-72 hours) Mucus: viscous fluid secreted by GI tract and other parts of the body, which moisten and lubricate cells from the harsh outer environments. STRUCTURE OF GUT WALL It contains 4 layers of tissue Lining of lumen is Mucosa. Mucosa: The layer of tissue lining the GI tract and other body cavities that serves as a protective layer and is responsible of for the absorption of end products of digestion.

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- Mucosal cells --> high nutrient requirements --> first to be affected by nutrient deficiencies - Layer surrounding mucosa- connective tissue containing blood and vessels --> provides support and nutrients to mucosa - Smooth muscles: non-voluntary control; the contraction mixes food particles into smaller pieces and provides support and protection. DIGESTIVE SECRETIONS - Aid the digestion inside the lumen inside of GI tract - It moistens, lubricates and protects the digestive tract Enzymes: the protein molecules that speed up the reaction, without being consumed in the reaction themselves.

ENZYME

WHERE IS IT FOUND

WHAT IT DOES

Salivary amylase

mouth

Breaks starch into smaller carbohydrate molecules

rennin

stomach

Causes the milk protein casein to curdle

pepsin trypsin

Breaks proteins into polypeptides and amino acids pancreas

Breaks proteins and Breaks polypeptides into shorter polypeptides

chymotrypsin

Breaks proteins and polypeptides into smaller polypeptides

carboxypeptidase

Breaks polypeptides into amino acids

Pancreatic lipase

Breaks TG --> monoglycerides, fatty acids and glycerol

Pancreatic amylase

Breaks starch into shorter glucose chains and maltose

Carboxypeptidase, aminopeptidase and dipeptidase

Small intestine

Breaks polypeptides into amino acids

lipase

Monoglycerides--> f.a. and glycerol

sucrase

Sugar-->glucose and fructose

lactase

Lactose-->glucose and galactose

maltase

Maltose--> glucose

dextrinase

Short chains of glucose-->individual glucose molecules

Regulation of GI tract - Nerve signals regulate activity - Hormones regulating the GI function are produced by cells lining the cells lining t...