Food and Nutrition_ Week 1-5.docx

Food and Nutrition: Week 1 - Nutrition: the study of food including, how food nourishes our bodies and how food influences our health Nutrition encompasses the following aspects of food: Consumption Digestion Absorption Metabolism Storage Excretion Wellness: physical, emotional, social, occupational...

Food and Nutrition: Week 1 - Nutrition: the study of food including, how food nourishes our bodies and how food influences our health Nutrition encompasses the following aspects of food: Consumption Digestion Absorption Metabolism Storage Excretion Wellness: physical, emotional, social, occupational, and spiritual health Critical components of wellness: nutrition and physical activity Nutrition can prevent disease: Nutrient-deficiency diseases: Scurvy, goiter, rickets, pellagra Scurvy: Vitamin C deficiency Goiter: iodine deficiency Rickets: vitamin D deficiency Pellagra: vitamin B deficiency Diseases influenced by nutrition: Chronic diseases: heart disease, type 2 diabetes Diseases in which nutrition plays a role: Osteoarthritis, osteoporosis, obesity Nutrients: chemicals in foods that are critical to human growth and function There are 6 groups of essential nutrients found in foods Carbohydrates Fats and oils (lipids) Proteins Vitamins Minerals Water Macronutrients: nutrients required in relatively large amounts (g or kg) Provide energy Carbohydrates, fats, and oils, proteins Micronutrients: nutrients required in smaller amounts (ug or mg) Vitamins and minerals Kilocalorie: the amount of energy required to raise the temperature of 1kg of water by 1 degree In canada: 1 kcal=4.184 KJ Carbohydrates: The primary source of fuel for the body, especially for the brain, and during exercise Provide 17 KJ/4 kcal per gram 1 gram = 4 cals Found in grains (wheat, rice), vegetables, fruits, and legumes Fats and oils: Composed of lipids, molecules that are insoluble in water Provide 37 KJ/ 9 kcal per gram 1 gram = 9 cals Important energy source during rest or low-intensity exercise Found in butter, margarine, vegetable oils Source of fat-soluble vitamins and essential fatty acids Proteins: Chains of amino acids Can supply 17 KJ/ 4 Kcal of energy per gram, but are not a primary energy source 1 gram = 4 cals An important source of nitrogen Proteins are important for Building cells and tissues Maintaining bones Repairing damage Regulating metabolism Fluid balance Protein sources include meats, dairy products, seeds, nuts, and legumes Micronutrients: Vitamins and minerals are known as micronutrients Vitamins: organic molecules that assist in regulating body processes Vitamins are micronutrients that do not supply energy to our bodies Fat-soluble vitamins Water-soluble vitamins Fat-soluble vitamins: Vitamins A, D, E, and K Dissolve easily in fats and oils Fat-soluble vitamins can be stored in the body Toxicity can occur Water-soluble vitamins: Vitamin C and B Remain dissolved in water Excess water-soluble vitamins are eliminated by the kidneys and cannot be stored in our bodies Minerals: Inorganic substances required for body processes Important minerals include sodium, calcium, iron, potassium, and magnesium Minerals have many different functions, such as fluid regulation, bone structure, muscle movement, and nerve functioning Our bodies require at least 100mg/day of the major minerals Calcium, phosphorus, magnesium, sodium, potassium, and chloride Our bodies require less than 100mg/day of the trace minerals Iron, zinc, copper, iodine, and fluoride Water: Is a critical nutrient for health and survival Water is involved in many body processes: Fluid balance Nerve impulses Muscle contractions Nutrient transport Removal of wastes Chemical reactions DRIs (Dietary reference intakes): Amount of a nutrinet needed to prevent deficiency disease in healthy people Amount of a nutrinet that may reduce the risk of chronic disease Upper level of safety for nutrients Consist of 4 values: Estimated average requirement (EAR) The average daily intake level of a nutrient that will meet the needs of half of the healthy individuals Ex, iron in breastfeeding women need 6.5% of iron, less then half the women will not need as much 6.5%, while the other half will need more then the 6.5% of iron Recommended dietary allowance (RDA) The average daily intake level required to meet the needs of 97% to 98% of healthy individuals Ex, Vitamin D in adults between the ages of 19-70 is 750 units Adequate intake (AI) Recommended average daily intake level for a nutrient Tolerable upper intake level (UL) Highest average daily intake level that is likely to pose no risk of adverse health effects Estimated energy requirement (EER) Average dietary energy intake (Kcal) to maintain energy balance in health adults Based on age, gender, weight, height, and level of physical activity Acceptable macronutrient distribution range (AMDR) The portion of the energy intake that should come from each macronutrient Carbohydrates: 45-65% Fats: 20-35% Protein: 10-35% Should add up to 100% of the macronutrients Week 3: Healthful diet is adequate: An adequate diet provides enough energy, nutrients, and fiber to support a person’s health A diet adequate in one area can still be inadequate in another and a diet adequate for one person may not be adequate for another Many Canadians have inadequate intake of fibre and micronutrients because of low vegetable consumption Healthful diet is moderate: Another key to a healthful diet is moderation (not too much and not too little) A healthful diet contains the right amounts of foods for maintaining proper weight and nutrition Example: some people drink 3x710mL bottles of soft drink per day. To avoid weight gain, they may limit intake of other calories coming from healthful foods Healthful diet is nutrient dense: Nutrient density is the nutrient-to-energy ratio A nutrient dense diet is made up of less processed, higher quality foods and beverages that supply highest level of nutrients for lowest number of calories Health Canada is working on front-of-package labelling to inform consumers of high sodium, saturated fat and sugar containing pre-packaged food Example of a high and low nutrient density meal: Low nutrient density breakfast High nutrient density breakfast 1 c. puffed rice cereal with ½ c. whole milk 1 slice white toast with 1 tsp butter 125mL grape drink 1 c. cooked oatmeal with ½ c. skim milk 1 slice whole-wheat toast with 1 tsp butter 125mL grapefruit juice Sensory data influence food choices: Appetite is the psychological desire to consume specific foods Triggered by: Sight Smell (olfaction) Taste Texture (mouthfeel) Sound Sociocultural cues and emotions influence food choices Social events can influence food choices Associating foods with a location or celebration Example: Popcorn at the movies At holiday gatherings you may consume more “forbidden food” Culture influences food choices, but may play less of a role for recent immigrants because of food availability, advertisement How can reading food labels help you improve your diet: Health Canada and Canadian Food Inspection Agency (CFIA) provide direction on food labelling in Canada As of December 2021, all prepackaged food being manufactured or imported must comply with the labelling requirements Food label is a critical tool for making healthy, safe food choice The key elements that must be included on food labels 1.Nutrition Facts Table (NFT) 2.Ingredient list 3.Allergen declaration and gluten sources 4.Date marking 5.Country of origin claims 6.Composition claims 7.Nutrition claims 8.Methods of production claims 9.Common name Use the nutrition facts table to evaluate foods for a healthy diet Provides information on serving size, calories, 12 core nutrients Serving size: not necessarily the suggested quantity of food you should eat Calories: total number of calories in a serving. If you have more than the serving size, your intake of calories will be higher than what is listed % Daily Value: how much a serving of the food contributes to overall intake of the nutrient indicated 5% or less is a little 15% or more is a lot Core nutrients: provides information on fat, saturated fat, trans fat, carbohydrate, fibre, sugar, protein, cholesterol, sodium, potassium, calcium, iron Manufacturer can add nutrients (example: vitamin D) to Nutrition Facts Table Use the list of ingredients to evaluate foods for a healthy diet Must read the ingredient list to determine if a food contains an allergen or ingredient Example: whole grain Recent updates: List sugars together List food colours by common names Readability (text colour, size, bullets or commas etc.) Food labels can display a variety of claims Health Canada regulates 2 types of claims: Nutrient claims Health claims Claims are optional, but if used, follow strict regulations that are consistent and not misleading Claims must be approved by Health Canada Use nutrient content claims to make healthier food choices Refers to the amount of a nutrient in a food Example: A good source of iron % Daily Value serves as a basis for nutrient claims For nutrients you want to increase, look for words like: source, high/good source, very high/excellent source For nutrients you want to minimize, look for words like free, low, reduced Use health claims to make healthier food choices In Canada, a health claim is any representation in labelling or advertising that states, suggests or implies that a relationship exists between the consumption of a food and health Can be: Disease risk reduction claims Function claims Front-of-packaging labelling: helps consumers quickly identify foods high in saturated fat, sugars and sodium. Ex, Health Concern Nutrient Example of approved claim statement Osteoporosis Calcium “A healthy diet with adequate calcium and vitamin D, and regular physical activity, help to achieve strong bones and may reduce the risk of osteoporosis. Brand X‡ is an excellent source of calcium.” Ex, Health Concern Nutrient Example of approved claim statement Hypertension Sodium “A healthy diet containing foods high in potassium and low in sodium may reduce the risk of high blood pressure, a risk factor for stroke and heart disease. Brand X‡ is a good source of potassium and is low in sodium.” How do the canadian dietary guidelines promote a healthful diet? In 2019, Health Canada released new Canadian Dietary Guidelines Revised from 2007 version of Eating Well with Canada’s Food Guide Food Rainbow 2019 Canada’s Food Guide: For policy makers, public and healthcare professionals Updated information on sodium, added/free sugars and saturated faT Healthy eating habits Guidelines and Considerations in the 2019 Canada’s Food Guide: Foundations for healthy eating: foods that should be consumed regularly, plant-based, unsaturated fat, water Nutritious foods can be fresh, frozen, canned or dried Cultural preferences and traditions Energy balance Environmental impact Foods and beverages that undermine healthy eating: processed and prepared, have saturated fat, high in sodium or free/added sugar Sugary drinks, confectionaries, sugar substitutes Publicly funded institutions should align with Canada’s Dietary Guidelines Alcohol can contribute calories and increase risk of chronic disease Importance of food skills and literacy Food skills and opportunities to learn and share Reducing food waste Follow the plate pattern: Eat Well Plate ½ variety of fruits and vegetables: foundation of a healthy eating pattern, fresh/frozen/canned ¼ mixture of whole grains: feel full longer, fibre ¼ protein containing food, including plant-based options: plant-based foods are associated with reduced risk for disease (example: colorectal cancer) Glass of water: hydration, other body processes, limits calories, sodium, free sugar and saturated fat in other beverages What foods and beverages undermine healthy food choices? Limit highly processed food and drink, as they contain excess sodium, free sugars, and saturated fats Examples of low nutrient-dense but high energy-dense foods/beverages: Sugar-sweetened beverages Fast foods like French fries and burgers Frozen foods like pizza Healthy eating is more than just food choices The where, when, why, and how we eat also matter Practice mindful eating and pay attention to hunger cues and feelings of fullness Food skills (cooking, meal planning) support healthy eating Consider different food cultures and other healthy eating plans Canada’s Food Guide snapshot offered in over 30 different languages to reflect diversity in Canada Canada’s Food Guide is similar to Mediterranean Diet Promotes healthy eating habits Not all cultural foods or popular diets are healthy Consider method of cooking, sauces Popular diets are promoted by celebrities or best-selling books or videos Diet industry in Canada generates ~$7 billion CAD Concern about what happens when the person comes off the diet, weight regain Nutrient deficit can be unhealthy Avoid large portions: 54% of Canadians eat out more than once per week, 30% of total budget spent on food every year Avoid large portions at restaurants/fast food outlet A restaurant meal can be equivalent to the recommended fat or calorie intake for an entire day! Ex, Menu Item kcal Fat (g) Fat (% kcal) Sodium (mg) McDonald’s Blank Blank Blank Blank Hamburger 240 8 30 510 Cheeseburger 290 11 34 700 Quarter Pounder with Cheese 520 26 45 1080 Big Mac 530 28 46 950 French fries, small 240 11 43 180 French fries, medium 350 17 42 260 French fries, large 560 27 42 420 Coke, large 320 0 0 5 McCafé Chocolate Shake (small) 560 14 24 400 McCafé Chocolate Shake (large) 1150 29 23 820 Tips for restaurant meals (adapted from p27) Avoid all-you-can-eat buffets Avoid appetizers that are breaded, fried, filled with cheese or meat Order an appetizer as a entrée Order broth-based soup instead of cream-based Select a lean meat and ask for it to be grilled Order a chicken, fish, veggie burger instead of beef Order pasta with tomato sauce instead of cream sauce Order a meatless dish A healthful eating pattern is founded on 3 key principles: An eating pattern includes all foods and beverages consumed. Everything you consume “counts”. Nutrient needs should be met primarily from nutrient-dense foods. Healthful eating patterns are adaptable, meaning that there are many ways to achieve a healthful pattern within your sociocultural environment A Mediterranean-Style Eating Pattern is Healthful Rates of cardiovascular disease in many Mediterranean countries are lower than rates in Canada Features: Red meat consumed monthly, eggs, poultry, fish and sweets are consumed weekly Primary fat is olive oil Foods eaten daily include grains, fruit, beans, legumes, nuts, vegetables, cheese, yogurt Wine in moderation The DASH Diet Follows a Healthful Eating Pattern Dietary Approaches to Stop Hypertension (DASH) Reduce the sodium in the diet, but emphasis is on vegetables, fruits, low-fat dairy, whole grains, poultry, fish and nuts Focus on potassium, calcium, magnesium, fibre, lean protein Vegetarian diets are healthful eating patterns Focus on plant-based foods Types: Lacto-ovo vegetarian Lacto-vegetarian Ovo-vegetarian Vegan Associated with improvements in weight management/loss, cardiovascular, cancer, diabetes risk The Portfolio Diet follows a healthful eating pattern 4 main components of the Portfolio diet 45g of nuts (handful) 50g plant protein such as soy and pulses 20g of viscous-soluble fibre from foods such as oats, eggplant, apples 2g of plant sterols found in foods such as margarine Associated with reductions in blood pressure, triglycerides, inflammation, blood cholesterol The Nordic Diet follows a healthful eating pattern Focused on plant-based foods and shares similarities with Mediterranean Diet, focus on sustainability and local foods Popular in Denmark, Sweden, Finland Features: Quality whole grains, fruits and vegetables Fatty fish, high-quality lean meat, low-fat dairy and eggs Plentiful in nuts, seeds, legumes Primary fat is canola oil Include regular physical activity Canadian Dietary Guidelines include a key recommendation that people should meet Canadian 24-Hour Movement and Activity Guidelines At least 150 minutes per week of moderate intensity physical activity And, muscle strengthening exercises on 2 or more days Helps reduce the risk of disease Week 4: What are carbohydrates: “Hydrated carbon”, meaning that it contains water Composed of the atoms: carbon, hydrogen, and oxygen Mostly from plant foods, such as fruits, vegetables, legumes, and grains Plants make glucose through photosynthesis Oxygen is released as a by-product of the reaction Plants store glucose as starch and use starch to support growth Simple carbohydrates include monosaccharides and disaccharides Simple carbohydrates: referred to as sugars Monosaccharides consist of a single sugar molecule Mono = one Saccharide = sugar Disaccharides consist of two molecules of sugar Di = two *Know these examples for test * Monosaccharides: Glucose, fructose, galactose are the most common in our diet arrangement of atoms à differences in sweetness Glucose is the most abundant sugar in our diet and is the preferred source of energy for the brain Fructose is the sweetest sugar, found in fruits, vegetables Galactose does not occur alone in foods Disaccharides: lactose, maltose and sucrose are most common Lactose: milk sugar, glucose + galactose Maltose: malt sugar, glucose + glucose, formed by fermentation of carbohydrates in grains and other foods into alcohol Sucrose: sweeter than lactose and maltose, glucose + fructose, responsible for sweetness of table sugar, honey, fruit/vegetables Polysaccharides are complex carbohydrates Plants store glucose as polysaccharides in the form of starch Food sources: grains, legumes, tubers (potatoes, yams) Cells cannot use complex starch molecules, must break down into monosaccharides Plant starch is either amylose or amylopectin Some starch is not digestible (resistant starch), type of fibre Glycogen: storage form of glucose for all animals But, very little exists in meat that humans consumed as glycogen is broken down by enzymes after slaughter Stored in humans in muscle and liver Allows humans to release glucose to bloodstream Fibre: composed of long polysaccharide chains Body does not break down fibre, so most fibre passes through the gastrointestinal tract without being digested and absorbed Dietary fibre: the nondigestible part of plants, plant “skeleton” Functional fibre: nondigestible form of carbohydrate with known health benefits, extracted from plants or made in laboratory Examples: cellulose, guar gum, pectin, psyllium Total fibre = dietary + functional fibre Fiber: Fibre can be classified as soluble or insoluble Soluble fibre: dissolves in water, forms gel when wet, fermentable and digested by bacteria in colon Found in citrus fruits, berries, oats, and beans Reduces risk of cardiovascular disease and type 2 diabetes by lowering blood cholesterol and glucose levels Examples: pectins, fructans, gums, mucilages Insoluble fibre: do not dissolve in water, cannot be fermented by bacteria in colon Found in whole grains, vegetables Promote regular bowel movements, alleviate constipation Reduces risk of diverticulosis (pockets within intestinal walls, food can get trapped, then inflamed and infected) Examples: lignins, cellulose, hemicellulose Carbohydrates provide energy for daily activities and exercise 4 kcal/gram Glycolysis: break down of glucose for energy (ATP) and intermediary molecules (pyruvate) Red blood cells use only glucose, brain and other nervous tissues rely primarily on glucose Hypoglycemia: blood sugar levels are low We rely mostly on both carbohydrates and fat for energy Carbohydrates fuel exercise, as glucose can be broken down quickly, with or without oxygen If you are physically active, it is important to eat enough carbohydrates to fuel brain, red blood cells and muscles if you are lacking, body will rely on fat and protein as alternative energy sources Carbohydrates spare protein and prevent ketoacidosis If diet is insufficient in carbohydrates, body will make its own glucose from protein by gluconeogenesis Less amino acids available to make new cells, repair, support immune system Ketone production will occur when diet is insufficient in carbohydrates to supply glucose to brain Important process during sleep, vigorous exercise Ketoacidosis: high ketone levels, increases acidity Fibre helps us stay healthy Diverticulosis: Promotes bowel health: prevents hemorrhoids, constipation and other intestinal problems Reduces risk of diverticulosis: condition caused by trying to eliminate small, hard stools Reduces risk of colon cancer and other cancers of the digestive system: fibre binds to cancer-causing agents and speeds up elimination Fibre helps us stay healthy Enhances weight loss: helps people feel more full, absorbs water to expand large intestine, slows movement of food Reduce risk of cardiovascular disease: delay or block absorption of dietary cholesterol Reduce risk of type 2 diabetes: slows release of glucose into blood, improves body’s regulation of insulin production Liver: detoxifies our bodies Synthesizes bile using cholesterol Gallbladder: stores bile LDL: keep low, high fibre diet HDL: keep higher, low fibre diet Digestion breaks down most carbohydrates into monosaccharides Chemical digestion begins in the mouth with salivary amylase Most chemical digestion of carbohydrates occurs in the small intestine Pancreatic amylase: secreted by pancreas Additional enzymes (maltase, sucrase, lactase) break down disaccharides into monosaccharides The liver converts most nonglucose monosaccharides into glucose Fructose and galactose are converted to glucose If glucose is needed, it is released to blood to provide energy through glycolysis If glucose is not needed, it is stored as glycogen in liver, muscle Broken down through glycogenolysis Fibre is excreted from the large intestine Humans cannot break down fibre Fibre passes through small intestine undigested and enters large intestine or colon In colon, bacteria ferment soluble fibre causing production of gases and short-chain fatty acids, which can be used as energy by cells of intestine Insulin and glucagon regulate blood glucose levels When you eat a meal, blood glucose rises, Insulin is released by pancreas (beta cells) to transport glucose into cells When you have not eaten for some time, blood glucose declines Glucagon is released from pancreas (alpha cells) to trigger glycogenolysis to convert stored glycogen to glucose, and stimulates gluconeogenesis Fructose does not stimulate insulin release Fructose is absorbed farther down the small intestine and does not stimulate the release of insulin Insulin release inhibits food intake, thus people consuming fructose might consume more total energy Fructose cannot enter brain cells and stimulate satiety signals Other hormones increase blood glucose levels Epinephrine, norepinephrine: secreted by adrenal glands Trigger glycogen breakdown in liver Increase gluconeogenesis Cortisol, growth hormone: secreted by adrenal glands to act on liver, muscle and adipose tissue Cortisol increases gluconeogenesis, decrease use of glucose by cells Growth hormone decreases glucose uptake by muscle The glycemic index shows how foods affect our blood glucose level Glycemic index: a measure of a food’s ability to raise blood glucose levels, compared to effect of pure glucose High glycemic index, surge in blood glucose, rise in insulin, dramatic drop in blood glucose Glycemic load: amount of carbohydrate in a food multiplied by its glycemic index and divided by 100 Considered a more useful tool than glycemic index The Recommended Dietary Allowance (RDA) for total carbohydrate reflects glucose use by the brain RDA for adults 19 years of age and older = 130g 45–65% total energy intake from carbohydrates Health Canada emphasizes that most carbohydrates should be high in fibre, whole-grains and unprocessed 2019 Canada Food Guide: half of grains should be whole grains, half of plate fruits and vegetables Most Canadians eat too much added sugar Simple sugars account for 17-25% of total energy intake, children consume the highest percentage of simple sugars Added sugar: sugar and syrup that is added to food during processing or preparation Example: white/brown sugar, honey, maple syrup, corn sweeteners Not included on food label, but total sugars indicated with % daily value Sugars are blamed for many health problems Can cause dental problems and tooth decay: World Health Organization recommends intake of added sugar ≤ 10% energy intake, and ideally ≤ 5% to protect dental health Unhealthful changes in blood lipids: changes in lipoproteins that are risk factors for cardiovascular disease Diabetes and obesity: cause surge in glucose and insulin, increase in weight due to excess calorie intake Whole grains are excellent sources of fibre The Adequate Intake (AI) of fibre is 14 grams/1,000 kcal in the diet daily (or 25 g for women, 38 g for men) Whole-grain foods (grains, vegetables, fruits, nuts, legumes) are much more healthful sources than foods with added sugar or fibre Whole grains are kernels that retain the bran, endosperm, and germ Bran is very high in fibre, contains most vitamins and minerals In Canada, manufacturers of bread and other baked goods made with white flour are required to enrich products with vitamins and minerals Enriched foods are food in which nutrients that were lost during processing have been added back Fortified foods have nutrients added that did not originally exist in the food (or existed in insignificant amounts) Example: breakfast cereal fortified with iron Other good sources of fibre are vegetables, fruits, nuts and seeds Canadians do not eat enough fruits and vegetables Legumes, leafy or crunchy greens are good sources of fibre Nuts and seeds are excellent sources of fibre 1 ounce of almonds = 4 g fibre Quinoa = 5 g per serving Alternative sweeteners: Nutritive sweeteners contain 4 kcal energy per gram Examples: sucrose, fructose, honey, brown sugar Sugar alcohols contain 2–3 kcal energy per gram Examples: mannitol, sorbitol, isomalt, xylitol Decrease glycemic response, decrease risk of dental caries Non-nutritive (alternative) sweeteners provide little or no energy Developed to sweeten foods without the usual risks Limited use of alternative sweeteners is not harmful Acceptable Daily Intake (ADI) is the amount of sweetener that someone can consume without adverse effects Saccharin: 300 times sweeter than sucrose, ADI = 5mg/kg/d (to be avoided with pregnancy) (sweet and low, sugar twins) Acesulfame-K: used to sweeten gums, candy, beverages, instant tea, coffee, gelatins, puddings Calorie-free, 200 times sweeter than sucrose Body does not metabolize Aspartame: also called Equal (the blue packet), Nutrasweet One of the most popular sweeteners available in Canada 180 times sweeter than sucrose 4 kcal/gram, but very small amounts used Health Canada states that there is no evidence for claims of cancer and nerve disorders ADI = 40mg/kg/day Sucralose: also known as Splenda, 600 times sweeter than sucrose ADI = 9mg/kg/day Neotame: 7000 times sweeter than sucrose Used to sweeten beverages, dairy, frozen desserts, gum Advantame: approved in Canada in 2017 Calorie-free 20,000 times sweeter than sucrose Safe for people with phenylketonuria Stevia: from stevia plant, 200 times sweeter than sucrose Also called Krista, Truvia, Pure via The effect of alternative sweeteners on body weight and other health outcomes is unclear Inconsistent evidence for weight loss and harm (example: dental caries, short-term food intake, kidney disease, cancer, headache, neurological effects), but long-term consumption may harm health Read Nutrition Facts, as sugar-free doesn’t mean calorie free 2019 Canada Food Guide recommends not using foods containing sugar substitutes Diabetes: Body can no longer regulate glucose and hyperglycemia (high blood glucose) becomes chronic Type 1 diabetes, type 2 diabetes, gestational diabetes Some ethnic groups and Indigenous populations are at higher risk Increases risk of heart, kidney and microvascular disease In type 1 diabetes, the body does not produce enough insulin 9% of people in Canada with diabetes have type 1 diabetes, most in adolescents Pancreas is not able to secrete insulin, glucose cannot move into cells Risk of fatal ketoacidosis In type 2 diabetes, cells become less responsive to insulin Accounts for 90% of cases in Canada Body cells become insensitive or unresponsive to insulin Obesity is most common trigger Variations include insulin resistance, impaired fasting glucose, and prediabetes Type 1 Diabetes Type 2 Diabetes Increased or frequent urination Any of the type 1 signs and symptoms Excessive thirst Greater frequency of infections Constant hunger Sudden vision changes Unexplained weight loss Slow healing of wounds or sores Extreme fatigue Tingling or numbness in the hands or feet Blurred vision Very dry skin Some diabetes risk factors are modifiable Age, family history and ethnicity are unmodifiable risk factors Metabolic syndrome (abdominal obesity, high blood pressure, high blood glucose, unhealthful levels of lipids) increases risk of type 2 diabetes Criteria for metabolic syndrome are modifiable Lifestyle changes can reduce your risk: Limit intake of added sugar Choose fiber-rich whole grains and whole grain products in place of refined, processed carbohydrates Limit consumption of red and processed meats Moderate exercise may prevent the onset of diabetes Week 5: lipids Lipids: Fats are one type of lipid Lipids: diverse class of organic substances that are insoluble in water Lipids (fats) do not dissolve in water Some are solid and some are liquid at room temperature 3 types of fats: Triglycerides, phospholipids, sterols Triglycerides are the most common food-based fat Most of the fat we eat is in the form of triglycerides About 95% of the fats we consume Triglycerides are composed of 3 fatty acids and 1 glycerol Fatty acids: long chains of carbon atoms surrounded by hydrogen atoms Glycerol: a three-carbon alcohol that is the backbone of a triglyceride Phospholipids combine lipids with phosphate Phospholipids are found in cell membranes, made in the body Found in egg yolks, liver, peanuts and soybeans Used as an emulsifier in salad dressing and mayonnaise Help with the digestion of dietary fat because the liver uses lecithin to make bile Sterols have a ring structure Part of cell membranes, helps to maintain cell integrity, made in the body Cholesterol is the most common sterol in the diet Primarily found in animal products such as butter, egg yolks, whole milk, meat, poultry Cholesterol used to make sex hormones, adrenal hormones, bile, and vitamin D Phytosterols are plant-based sterols and stanols found in plant foods such as cereals, vegetable oil, seeds and nuts May have health benefits by reducing absorption of dietary cholesterol and increasing cholesterol excretion in feces Portfolio dietary pattern is associated with changes in LDL cholesterol that are similar to cholesterol medication Consists of nuts, plant protein, soluble fibre, plant sterols Triglycerides: Triglycerides can be classified by: Length of their carbon chain: number of carbons in fatty acid Level of saturation: how much Hydrogen is attached to the carbon atoms Shape: determined by how the fat is chemically processed Fatty acid chain length affects digestion and absorption Short-chain fatty acids are fewer than 6 carbon atoms Medium-chain fatty acids are 6-12 carbons Long-chain fatty acids are 14 or more carbons Short and medium chain fatty acids are digested and absorbed more quickly than long-chain fatty acids Level of hydrogen saturation influences health effects Saturated fatty acids (SFA): hydrogen atoms surrounding every carbon in the chain and no double bonds Monounsaturated fatty acids (MUFA): lack hydrogen atoms in one region and have one double bond Polyunsaturated fatty acids (PUFA): lack hydrogen atoms in multiple locations and have two or more double bonds Examples of foods containing high amounts of different types of fatty acids: Saturated fatty acids (SFA): coconut oil, palm oil, palm kernel oil, butter, cream, whole milk, lard, beef Monounsaturated fatty acids (MUFA): olive oil, canola oil, cashew nuts Polyunsaturated fatty acids (PUFA): canola oil, corn oil, safflower oil Carbon bonding influences shape Saturated fatty acids can pack tightly together and are solid at room temperature Example: coconut oil, animal fats, butter, and lard Double bonds in unsaturated fats causes kink along their length, making them liquid at room temperature Trans fatty acids are especially harmful Unsaturated fatty acids can occur in cis or trans shape Cis: hydrogen atoms on the same side of double bond Trans: hydrogen atoms on diagonally opposite sides of double bond, naturally occurring and manufactured Hydrogenation alters unsaturated fatty acids, such as corn and safflower oils, straightening the fatty acid chain Allows fat to be stored in solid form, prevents rancidity Canada’s Dietary Guidelines recommend keeping trans fat intake as low as possible Trans fat intake is associated with cardiovascular disease Trans fat ban in Canada (2018): prohibition of use of partially hydrogenated oils (PHO) in foods sold in Canada Nutrition facts tables allow use of 0 trans fats if the product has less than 1g of trans fats per serving Essential fatty acids have unique health benefits Fatty acids that cannot be synthesized in the body and must be obtained from foods that we eat 2 kinds of essential fatty acids: Omega-6 fatty acids Omega-3 fatty acids Omega-6 fatty acids have a double bond 6 carbons from the omega end of the fatty acid Linoleic acid is essential for health Found in vegetable, sunflower, safflower, corn, soy and peanut oils Precursor to arachidonic acid, which regulates inflammation Concerns that increased intake of linoleic acid may have negative implications for cardiovascular disease Omega-3 fatty acids have a double bond 3 carbons from the omega end of the fatty acid Most common omega-3 fatty acid in our diet is alpha linolenic acid (ALA) Found in dark green leafy vegetables, flaxseeds and flax oil, soybeans and soybean oil, walnuts and walnut oil and canola oil Converted to eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), but conversion is limited (10% to EPA, 1% to DHA) EPA and DHA are found in fish, shellfish and fish oils Fatty fish such as salmon and tuna are higher in EPA and DHA, compared to lean fish such as cod and flounder Recommendation of 2 servings of fish per week Essential fatty acids are precursors to eicosanoids, which regulate cell function Example: GI motility, blood clotting, blood pressure, vessel permeability, inflammation Fats provide energy Fat is very energy dense, providing 9 kcal/gram 30-70% of the energy used at rest comes from fat Fatty acids, carried by albumin, are used for energy during low to moderate intensity physical activity exercise Fat is also used for energy storage in adipose tissue Fats enable transport of fat-soluble vitamins Vitamins A, D, E, and K are soluble in fat, and fat is required for absorption across intestinal wall Vitamin A: essential for vision Vitamin D: maintain bone health Vitamin E: protects cell membranes from by-products of metabolism Vitamin K: important for blood clotting Fats help maintain cell function Phospholipids, cholesterol and fatty acids help maintain cell membrane integrity, permeability of cell and regulate binding of substances to the cell Fats help maintain membrane fluidity and flexibility Enable red blood cells to move through small capillaries Polyunsaturated fatty acids (PUFA) are important for healthy brain and spinal cord tissue Body fat provides protection Adipose tissue pads our body and protects organs, such as kidneys and liver Fat also acts as insulation to retain body heat But, too much stored fat in the abdominal region is a risk factor for metabolic syndrome, which increases risk for type 2 diabetes and cardiovascular disease Dietary fats contribute to the flavour, texture and satiety of foods Fat provides flavour and texture to foods Example: creamy, crisp, moist, tender Fat contributes to satiety responses and makes us feel satiated Fats take longer to digest Fats have a higher energy density than protein and carbohydrates How the body process fats: Fats are not soluble in water and cannot enter the bloodstream easily from the digestive tract Salivary enzymes, lingual lipase play little role in digestion of fats, and most fats reach the stomach intact At the stomach, small amount of lipolysis by gastric lipase As fat enters the small intestine: Bile is secreted from the gallbladder into the small intestine Bile is produced by the liver and stored in the gallbladder Bile disperses fat into smaller fat droplets Pancreatic enzymes break triglycerides into two separate fatty acids and a monoglyceride Fat enters the mucosal cell as a micelle (fatty acids, monoglycerides, phospholipids, and sterols) The gallbladder, liver and pancreas assist in fat digestion As fat enters the small intestine, bile is secreted from the gallbladder into the small intestine Bile is produced by the liver and stored in the gallbladder Bile breaks up fat into smaller fat droplets Pancreatic lipase begins to digest the triglycerides into break triglycerides into 2 fatty acids and 1 monoglyceride Products are trapped in micelles and transported to the enterocytes Absorption of fat occurs primarily in the small intestine Short and medium chain triglycerides absorbed by passive diffusion Long chain fatty acid absorption occurs in enterocytes with the help of micelles Fatty acids and monoglycerides are packaged into lipoproteins Chylomicron is an example of a lipoprotein that is produced by enterocytes to transport fat Chylomicrons are the transport vehicles that remove absorbed fats from the small intestine Chylomicrons are soluble in water because of phospholipid and protein composition Chylomicrons are transported to lymphatic system through the lacteals to the subclavian vein Lipoprotein lipase (LPL) outside adipose and muscle cells breaks apart triglycerides in chylomicrons Free fatty acids move into the cell Glycerol transported back to kidney or liver Fat is stored in adipose tissue for later use 3 fates of fatty acids delivered by chylomicrons: Body cells take up fatty acids and use as a source of energy Cells use them to make lipid-containing compounds If body doesn’t need energy, muscle and adipose cells can re-create triglycerides and store them for future use Recognize the fat in foods Visible fats: fats we can see in foods or can easily see have been added to foods Examples: butter, cream, mayonnaise, salad oils Hidden fats: fats added to processed or prepared foods to improve texture or taste Fat in baked goods, dairy products, processed meat, convenience foods Most of the fat in Canadian diet is hidden Decipher label claims Canadian Food and Drug Regulations for allowable label claims for reduced fat products Fat free = 0.5g fat Low fat = 3g fat or less Reduced fat or light = at least 25% less fat compared to similar food Lower-fat versions may not always be lower in calories Keep your fat intake within the AMDR The Acceptable Macronutrient Distribution Range (AMDR) for fat is 20–35% of total daily energy intake Athletes: more energy from carbohydrates, can reduce fat intake to 20–25% of total daily energy intake No clear evidence that diets with less than 15% of total energy from fat has weight-loss advantage over moderate fat diets Aim for a balance of the essential fatty acids Linoleic Acid (omega-6) AI:14–17g/day for men and 11–12g/day for women Alpha-linolenic acid (omega-3) AI:1.6g/day for men and 1.1g/day for women Eicosanoids from the omega-6 family are pro-inflammatory and those from omega-3 family are anti-inflammatory Limit foods that contain saturated fats Canada’s Dietary Guidelines: limit saturated fat intake to less than 10% of total energy 50% of Canadians consume too much saturated fat Consume foods that contain mostly unsaturated fat Examples of foods with saturated fats: ultra-processed foods, full fat meat and dairy, baked goods, sweets, snack foods, prepared vegetables, salad dressing, condiments Be aware of fat replacers Fat replacer: ingredient that performs the function of fat but yields fewer calories Fat substitutes, analogs, extenders, mimetics Examples: cellulose gel, dextrins, guar gum, gum arabic Olestra, a fat replacer in the U.S. market is not approved for use in Canada as there is no support for weight loss or management Fat replacers and weight management Lower fat products can reduce the amount of fat consumed, but may or may not reduce the number of calories consumed Example: Oreos 33% less fat cookies versus regular Oreos à limited impact on energy and fat intake Choosing low or reduced fat products does not mean that you can eat all you want without gaining weight Fat is often replaced with added carbohydrate What is cardiovascular disease? Group of conditions that affect structure and function of the heart and blood vessels Highest mortality rates for: Ischemic heart disease (IHD) or coronary heart disease (CHD): heart muscle is damaged and does not function properly Stroke (cerebrovascular disease): blood vessel blockage (ischemic stroke) or rupture (hemorrhagic stroke) Arteriosclerosis vs. atherosclerosis: what is the difference? Arteriosclerosis: hardening of arterial walls Atherosclerosis: accumulation of cholesterol-rich plaque on artery walls that result in hardening of the wall Atherosclerosis is narrowing of arteries Complex process that begins with injury to the cells that line insides of vessels Injury caused by: high blood pressure, irritants (nicotine in tobacco), high blood glucose, immune response from chronic infection Injury leads to vessel inflammation, which is a marker of CVD Cardiovascular disease: Chemicals are released that cause blood lipids to accumulate at the site of injury Mainly low density lipoproteins (LDL) LDL invade lining of artery wall and become oxidized, which activates immune cells and forms foam cells and fatty streaks Plaques form, narrowing the interior of the blood vessel, decreasing blood supply to downstream tissues Hypertension increases the risk for heart attack and stroke One of the most common chronic diseases in Canada 24% of the male and 23% of the female population Warning sign for risk of developing heart disease or stroke Various types of hypertension, but the most common type(95% of hypertension cases) is primary hypertension (essential or idiopathic), which has no identifiable cause What factors influence the risk for cardiovascular disease? Modifiable risk factors for cardiovascular disease: Overweight and obesity Inactivity Smoking Type 2 diabetes mellitus Inflammation Abnormal blood lipids Blood lipids play a significant role in cardiovascular disease Chylomicrons: transport dietary fat to lymphatic vessels, 85% triglyceride, lowest density Very-low-density lipoproteins (VLDL): transport triglycerides to body cells, more than 50% triglyceride, liver is the primary source Diet high in fat, simple sugar and extra calories can increase VLDL Blood lipids play a significant role in cardiovascular disease Low-density lipoproteins (LDL): deliver cholesterol to cells, more dense, higher in cholesterol, phospholipids and protein Increases risk of CVD Diets lower in simple carbohydrate and saturated fat and regular physical activity can lower LDL High-density lipoproteins (HDL): pick up cholesterol from cells and plaques and transfer to other lipoproteins You can estimate your risk for cardiovascular disease Canadian Cardiovascular Society recommends using: Framingham Risk Score (FRS) Cardiovascular Life Expectancy Model (CLEM) Low risk: FRS<10% intermediate risk: FRS 10-19% High risk: FRS greater than or 20% TEST 1 REVIEW: 10 questions of intro Know the difference between macro and mirco nutrients Know the 6 classes of nutrients Water soluble vs fat soluble vitamins Energy from nutrients, calculation question Know terms: DRI, RDA, EER, DV% (what do the letters stand for and what they are based on) Scientific method, what to believe 5 questions of week 2 Food labels Ingredient list - desceinding order by weight Nutritional facts table – standard format, list of nutrients. %DV; nutrient content claims; health claims; What is an adequate diet? What is a calorie? What is nutrient density 17 questions of carbohydrates Simple CHO Complex CHO Digestion of CHO Glycemic Index – see pdf Difference between Sweeteners – see pdf *what to avoid when preggo* 8 questions of lipids 3 types Triglycerides Hydrogenation Essential fatty acids – need to eat Fat-soluble vitamins * High LDL (Bad) cholesterol * High HDL (Good) cholesterol