Chapter 1. Introduction to Nutrition

• What are the three basic functions of nutrients?
  • To provide energy, contribute to body structure, and regulate chemical processes of the body.  
• Define nutrients and list the six classes of nutrients required for the body to maintain normal function and overall health.
  • Nutrients are substances obtained from the diet that are required by the body to perform its basic functions. The six classes of nutrients are carbohydrates, lipids, proteins, water, vitamins, and minerals.
    • Protein: necessary for tissue formation, cell reparation, and hormone and enzyme production. It is essential for building strong muscles and a healthy immune system.
    • Carbohydrates: provide a ready source of energy for the body and provide structural constituents for the formation of cells.
    • Fat: provides stored energy for the body, and functions as structural components of cells and as signalling molecules for proper cellular communication. It provides insulation to vital organs and works to maintain body temperature.
    • Vitamins: regulate body processes and promote normal body-system functions. They are required to make red blood cells, synthesize bone tissue, and play a role in normal vision, nervous system function, and immune system function.
    • Minerals: regulate body processes, maintain fluid balance, build bone tissue, synthesize hormones, transmit nerve impulses, contract and relax muscles, protect against harmful free radicals, and play a critical role in enzyme function.
    • Water: involved in many bodily processes such as fluid balance and nutrient transport, nerve impulses, body temperature, muscle contractions, and excretion of waste products. We need water for chemical reactions, to cushion organs, and to survive.
• What is the difference between organic and inorganic nutrients? Give two examples of each.  
  • Organic nutrients contain carbon and inorganic nutrients do not contain carbon. Carbohydrates, lipids, proteins, and vitamins are organic whereas minerals and water are inorganic nutrients.  
• Which macronutrient provides the most energy per gram?  
  • Lipids (9 kcal/gram) compared to 4 kcal/gram of proteins and carbohydrates. 
• What are the three main types of lipids and what are the primary functions of lipids?  
  • Triglycerides, phospholipids, and sterols
  • The main job of lipids is to provide and store energy. Lipids are also major components of cell membranes and surround and protect organs while providing insulation to assist in temperature regulation and other bodily functions.
• Why are proteins considered essential for the body beyond energy production?  
  • Proteins provide structure to bones, muscles and skin, while supporting tissue growth, repair and maintenance. Proteins also conduct most of the chemical reactions that occur in the body. 
• Which vitamin plays an important role in vision, reproduction, and immune system function?  
  • Vitamin A
• Which vitamin deficiency can lead to pellagra? What are the common signs and symptoms of this disease?  
  • Niacin deficiency. The common signs and symptoms are known as the 4D’s- diarrhea, dermatitis, dementia, and death.  
• Carlos, a 28-year-old individual, has determined that they need to consume 2500 kcal per day. Based on this requirement, calculate the AMDR for both kcal and grams for carbohydrates, fats, and protein.
  • Carbohydrates: 2500 x 0.45= 1125, 2500 x 0.65=1625 (1125-1625 kcal of carbohydrates)
  • Protein: 2500 x 0.1= 250, 2500 x 0.35=875 (250-875 kcal of protein)
  • Fats: 2500 x 0.25=625, 2500 x 0.35=875 (625-875 kcal of fat)
  • Carbohydrates: 1125/4=281.25 and 1625/4=406.25 kcal (281.25- 406.25 g of carbohydrates)
  • Protein: 250/4= 62.5 and 875/4=218.75 (62.5- 218.75 g of protein)
  • Fats: 625/9=69.44 and 875/9=97.22 (69.44-97.22 g of fats)
• Aki is a 42-year-old female who weighs 60 kg and is 1.62 m tall. Each morning, Aki enjoys biking for at least 60 minutes with her best friend. Based on this information, what is Aki’s EER?
  • $$EER=354–(6.91\times \text{age})+PA\times \{(9.36\times \text{weight})+(726\times \text{height})\}$$
  • $$EER=354–(6.91\times 42)+1.27\times \{(9.36\times 60)+(726\times 1.62)\}=\; 2272.64\; kilocalories$$
• What does the evidence-based approach to nutrition include? 
  • Defining the problem or uncertainty
  • Formulating the problem as a question
  • Setting criteria for quality evidence
  • Evaluating the body of evidence
  • Summarizing the body of evidence and making decisions
  • Specifying the strength of supporting evidence required to make decisions
  • Disseminating the findings 
• What are the similarities and differences between Indigenous ways of knowing and Western science?  
  • Indigenous science also involves observation and experimentation just like Western science. However, unlike Western science, Indigenous ways of knowing adopt a holistic approach to exploring interrelationships between individuals and the natural world. On the other hand, Western science is rooted in objectivity and logic. It focuses on observable phenomena and does not always emphasize the relationships human beings share with the world around them.  
• What is the difference between epidemiological studies and intervention clinical trials?   
  • Epidemiological studies are observational studies of populations around the world and do not establish causation. Intervention clinical trials and scientific investigations in which a variable is changed between groups.  
• Why are randomized clinical trials considered the gold standard of research?  
  • In randomized clinical trials, participants are randomly assigned into separate groups that compare different treatments. Neither the participants nor the researchers know which group the participants are in. The double-blind nature of these studies eliminates researcher bias, preventing researchers from trying to see the results that support their hypothesis. Additionally, the placebo-controlled nature of these studies eliminates the placebo effect, so the participants’ expectations of the treatment/intervention minimally influence the study results.  
• Why is it important to consider who provided the funding when evaluating scientific conclusions?   
  • It is important to consider who provided the funding because not all scientific conclusions are developed in the interest of human health. Some scientific conclusions can be biased and made in favour of whoever provided the funding.  
• Describe two ways in which you can evaluate the validity of nutritional news sources.  
  • You should check to see that the scientific study is published in a peer-reviewed journal to make sure it is a trustworthy source.   
  • You should make sure that the study discloses the study methods in detail, so you are aware of the sample size, study duration, and how the researchers observed the results.  
• What are some common characteristics of fad diets that make them problematic?  
  • They focus on short-term goals rather than long-term goals. 
  • They focus on selective foods while eliminating other foods/food groups. 
  • They make claims not rooted in evidence-based research. 
  • They often fail to include PA guidelines/recommendations and fail to disclose the detrimental effects on individuals with chronic diseases. 
  • They promise “rapid” weight loss. 
  • They are unsustainable in the long-term. 
• What are some indicators that an article is peer-reviewed?  
  • Find the date the article was accepted by the journal, reviewed, revised by the author and finally published to confirm that it is peer-reviewed. 
  • You can also look at the layout: does it include a title, list of authors, and their affiliations, and an abstract? Does it include references throughout the article? 
•  Why is it important to cite the articles you reference in your work?  
  • Since you did not produce the new information, it is important to cite the articles to give credit to the authors. This is done to avoid plagiarism. 
•  Design a study to investigate the effects of blueberry supplementation on cognitive performance among college students. HINT: Consider the gold standard for scientific studies.  
  • Participants will be randomly assigned into two groups: placebo and treatment group. The placebo group will be receiving a sugar pill that replicates the taste, smell, and appearance of the blueberry supplement that will be given to the participants in the treatment group. The researchers will not know which participants are in which group to prevent researcher bias. 

Chapter 2. Designing a Healthy Diet

• How does variety contribute to a healthful diet, and why is it important to incorporate different foods from all food groups?  
  • Variety refers to consuming different foods from each of the different food groups regularly. By doing so, you increase your chances of consuming the daily nutrient requirements.  
• How does adequacy contribute to a healthful diet, and what types of food are considered nutrient-dense? Provide some examples. 
  • An adequate diet is one that provides enough energy, nutrients, fibre, and vitamins to maintain an individual’s health. It is a diet that avoids empty-calorie foods such as sugary drinks and favours nutrient-dense foods such as fruits and vegetables, lean meats, and whole grains.  
• Why is it important to consume foods in moderation? What are some of the health complications that can result from eating too much or too little?  
  • Moderation is really important for optimal health and survival. Eating nutrient-poor foods regularly may lead to health complications such as cardiovascular disease and obesity. On the other hand, engaging in extremely restrictive diet patterns and eating too little may also lead to negative health outcomes such as eating disorders and nutritional deficiencies.  
• Why is it important to have a balanced diet? Provide an example of how you can balance nutrients in your diet.   
  • It is important to have a balanced diet to ensure you are getting appropriate amounts of all nutrients, and not consuming one nutrient at the expense of another. You can balance nutrients in your diet by incorporating a mixture of foods from the different food groups (vegetables, legumes, fruits, grains, proteins, and dairy).  
• What are some of the systemic barriers that prevent everyone from having a healthy diet?  
  • Over 3 billion people globally face socioeconomic challenges and do not have sufficient income to afford healthy eating. Food deserts also exist in Canada and contribute to the lack of access residents have to stores and restaurants that provide fresh, healthy, and affordable foods.  
• List and briefly explain the four components of food labels in Canada.   
  • Ingredient List: The ingredients must be listed by their common names, in descending order by weight (e.g., the first ingredient has the highest weight). Ingredient lists are mandatory on all food labels. 
  • Nutrition Facts Table: The facts table has a consistent format and provides information on serving size,  calories, % daily value, and a core list of 13 ingredients: fat, saturated fat, trans fat, cholesterol, sodium, carbohydrate, fibre, sugars, protein, vitamin A, vitamin C, calcium and iron.  
  • Nutrient Content Claims: These are statements based on current scientific evidence that can be made when the product meets certain criteria. Nutrient content claims provide information about the amount of one specific nutrient in a food, such as fibre or fat. They are optional and must meet government regulations before appearing on a package. 
  • Diet-Related Health Claims: Health claims are statements that link a food or food component to a reduced risk of a disease or condition. 
• What are the four key components of the nutritional facts table? 
  • Serving size: this tells you how much food equals one serving (e.g., 20 crackers). All other values listed after (from calories to fibre content) are based on this one serving.  
  • Calories per serving: This tells you how many calories (kcal) you are consuming per serving (i.e. 140 kcal for 20 crackers).  
  • List of nutrients: a list of all the nutrients in that food (i.e. total fat, cholesterol, sodium, total carbohydrate, protein, vitamin A, vitamin C, calcium, iron, etc.) 
  • The % Daily Value represents the proportion of the total daily recommended amount that you will get from one serving of the food.  
• How can the nutrition facts table assist consumers in making informed nutritional choices?  
  • It provides so much information about the nutritional content of a product, allowing us to compare different products and look for healthier alternatives. We can look at serving sizes to see how much of each nutrient is in each serving to make accurate comparisons. 
• Explain the differences between the following food label claims: fat-free, low-fat, reduced-fat, and light-fat.   
  • Fat-free: the food contains less than 0.5 g of fat → the food provides such a small amount of fat that it is likely it won’t have an effect on your body. 
  • Low-fat: 3 g or less of fat → the food provides a very small amount of the nutrient 
  • Reduced fat:  the food is modified/processed so that it contains at least 25% less fat than the food to which it is compared.
  • Light-fat: the food provides at least 50% less of the added nutrient→ the food contains no added fats or oils or added butter or ghee, or ingredients that contain added fats of oils, or butter or ghee. 
• How have portion sizes changed in restaurants and eating establishments? How might this change influence our dietary intake?  
  • Compared to 20 years ago, portion sizes have increased in restaurants and eating establishments. People tend to eat more than they need to when given larger portions, which can lead to poor eating habits and adverse health outcomes.  

Chapter 3. Digestion, Absorption, and Elimination

• What is the difference between appetite and hunger? How might the distinction between the two allow us to develop healthier eating habits?   
  • Hunger is a physiological sensation that drives us to eat when we need food. Hunger is non-specific, which means that it can be satiated by any food.  On the other hand, appetite is a psychological desire to consume a particular food that can be triggered by things related to our culture, society, and environment. Understanding the difference between the two may help us avoid giving in to sudden cravings (i.e. craving ice cream when hearing/seeing an ice cream truck cross the street).  
• Explain the role of the hypothalamus and nerve cells in producing feelings of hunger and satiety.  
  • Nerve cells detect changes in pressure in the stomach and small intestine and send signals to the hypothalamus, which integrates a response, causing us to eat or feel full. When you have just eaten, the stomach or small intestine becomes distended/ full of nutrients which causes the nerve cells to send a signal to the hypothalamus, triggering feelings of satiety. On the other hand, when the stomach is empty, the nerve cells detect a lack of distention and nutrients and send signals to the hypothalamus, which results in feelings of hunger. 
• How does digestion begin before you even put food into your mouth? What is this phase of digestion called?  
  • The process of digestion begins when you start thinking about food. This is the cephalic phase of digestion. When you feel hungry, your body sends a message to your brain that it is time to eat. Sights and smells influence your body’s preparedness for food. Smelling food sends a message to your brain. Your brain then tells the mouth to get ready, you start salivating, and your stomach starts secreting gastric juices in preparation for your meal. 
• What is the difference between the mechanical and chemical breakdown of food?  
  • Mechanical breakdown of food involves chewing, which moistens the food, increases its surface area, mixes it together and stimulates the production of saliva. Mechanical digestion continues with churning and mixing actions in the stomach through peristalsis and segmentation. Chemical breakdown of food involves enzymes which break down the larger molecules of food into smaller components.  
• How do peristalsis and segmentation differ in propelling food down the GI tract?  
  • During peristalsis, the muscles of the esophagus contract to squeeze and push the food bolus down the stomach. When food enters the stomach, peristaltic contractions help mash and churn food into chyme and propel food forward. Segmentation from circular muscle contraction slows movement in the small intestine by forming sausage link segments that allow the chyme to slosh back and forth in both directions to promote mixing and absorption of nutrients.  
• How is the stomach lining protected against the highly acidic environment?  
  •  The stomach contains cells that secrete bicarbonate and mucus to help neutralize acid near the surface of the stomach lining and provide a protective layer against hydrochloric acid. 
• What is the primary role of the large intestine in the digestive process?  
  • Any food that is incompletely broken down and the food’s indigestible fibre content moves from the small intestine to the large intestine before they are eliminated as feces. The main job of the large intestine is to absorb much of the remaining water so excess amounts of water are not lost in fecal matter. No further mechanical/chemical breakdown takes place in the large intestine.  
• How do gastrointestinal disorders like ulcers and celiac disease affect one’s health and dietary habits?  
  • When areas of the GI tract become eroded by hydrochloric acid and pepsin, we might see gastric ulcers which are associated with burning pain, vomiting, and bloody stool. These unpleasant signs and symptoms may encourage individuals to eat foods that lower the amount of acid in their stomach while also alleviating symptoms of pain. Individuals with celiac disease may opt for gluten-free foods to avoid symptoms such as bloating, gas, diarrhea, nausea, vomiting, etc.  
• What structural characteristic(s) allows the small intestine to be the primary site of nutrient absorption?  
  • The surface area of the small intestine is greater than 200 square meters. The large surface area is due to the multiple levels of folding which maximize nutrient absorption. 
• What is the role of accessory organs such as the liver, pancreas, and gallbladder in the digestive process?  
  • The liver produces bile. 
  • The gallbladder stores and secretes bile which emulsifies fats into smaller droplets. 
  • The pancreas secretes pancreatic juices into the duodenum of the small intestine that further break down proteins, carbohydrates, and fats. The pancreatic juices also contain bicarbonate ions which neutralize the acidity of the chyme, allowing the pancreatic enzymes to work more effectively. The pancreas also produces glucagon and insulin.  
• What are the digestive health benefits of probiotic foods? Provide some examples of these foods.  
  • Probiotics are “friendly bacteria” that ward off viral-induced diarrhea and reduce symptoms of lactose intolerance. Probiotic foods include yogurt and Kefir.  

Chapter 4. Carbohydrates

• What is the difference between monosaccharides and disaccharides? Provide a few examples of each.   
  • Simple carbohydrates are also known more simply as “sugars” and are grouped as either monosaccharides or disaccharides.
  • Monosaccharides are single sugar molecules and include glucose, fructose, and galactose. Disaccharides are composed of pairs of monosaccharides linked together and include lactose, maltose, and sucrose.  
• What is the difference between soluble and insoluble fibres? Provide examples of each.   
  • Soluble fibres dissolve in water and can form gels that trap nutrients, such as glucose, and slow down absorption, which could be beneficial to those with diabetes. Soluble fibres are fermentable and more easily accessible to bacterial enzymes in the large intestine. Soluble fibres are often found in beans, citrus fruits, oats, barley, rye, and berries.
  • Insoluble fibres do not typically dissolve in water and are not typically fermented by bacteria in the colon. Cellulose, hemicelluloses, and lignins are examples of insoluble fibres found in whole grains, seeds, and fruits and vegetables.  
• Which enzymes are involved in the chemical digestion of carbohydrates and what are their respective roles?  
  • Salivary amylase breaks down amylose and amylopectin into smaller chains of glucose called dextrins and maltose.  
  • Pancreatic amylase further breaks down dextrins and any remaining polysaccharides into short and shorter carbohydrate chains.  
  • Sucrase breaks sucrose into glucose and fructose molecules. 
  • Maltase breaks the bond between the two glucose units of maltose. 
  • Lactase breaks the bond between galactose and glucose.  
• Which condition does a lactase enzyme deficiency lead to? How does this health condition influence one’s digestive process and dietary choices?   
  • Lactose intolerance. These individuals are unable to digest lactose which produces gases leading to symptoms of diarrhea, bloating, and abdominal cramps. Most of these individuals can tolerate some dairy products in their diet but may benefit from limiting their dairy intake to prevent bacterial digestion and its associated symptoms.  
• How does the pancreas regulate blood glucose levels in the body? 
  • When blood glucose levels are high, the pancreas releases insulin which sends a signal to the body’s cells to remove glucose from the blood and transport it to different organ cells around the body and use it to produce energy. As glucose is transported around the body, the blood glucose levels decrease. When blood glucose levels drop, the pancreas releases glucagon which communicates to the cells in the body to stop using glucose. It also signals the liver to breakdown glycogen into glucose so it can be released into the blood, allowing glucose levels to stay within the target range.    
• What is the difference between type I and type II diabetes? What are the complications associated with uncontrolled diabetes?  
  • Type 1 diabetes is known as insulin-dependent diabetes where the pancreas can’t produce insulin because the body attacks the pancreas. People with type 1 diabetes need to inject insulin or use an insulin pump to regulate insulin blood sugar levels. In those with type 2 diabetes, either the body can’t properly utilize the insulin produced or cannot produce enough insulin.  
  • Uncontrolled diabetes can damage arteries in the eyes and kidneys and result in retinopathy, blindness, high blood pressure, heart attack, and stroke.  
• What happens to any remaining indigestible carbohydrates in the large intestine?  
  • The remaining indigestible carbohydrates are broken down by enzymes released by bacteria in the large intestine. The products of bacterial digestion of these slow-releasing carbohydrates are short-chain fatty acids and some gases. The short-chain fatty acids are either used by the bacteria to make energy and grow, are eliminated in the feces, or are absorbed into cells of the colon, with a small amount being transported to the liver.  
• How can the glycemic index be used to make healthier carbohydrate choices? What are some of the limitations of using the glycemic index?   
  • Foods that have a low GI do not raise blood-glucose levels either as much or as fast as foods that have a higher GI. We can use the glycemic index to choose carbohydrates that have a low-GI. However, the GI has some limitations. The first is GI does not take into account the amount of carbohydrates in a portion of food, but only takes into account the type of carbohydrate. Another is that combining low- and high-GI foods changes the GI for the meal. Also, some nutrient-dense foods have higher GIs than less nutritious food. Lastly, meats and fats do not have a GI since they do not contain carbohydrates. 
• Under which circumstances can carbohydrate loading optimize athlete performance and how? HINT: Think about muscle glycogen reserves and how long they typically last.  
  • Endurance athletes can benefit from carbohydrate loading to prevent depletion of muscle glycogen stores which can cause a decrease in performance levels. After prolonged exercise, muscles rely more on lipids and proteins as an energy source as glycogen stores become depleted. Athletes can increase their glycogen reserve by reducing training intensity and increasing their carbohydrate intake, but this will only be beneficial to those with exercise durations longer than 90 minutes. If events are longer than 45 minutes, people can reduce stored glycogen use by ingesting carbohydrates during activity. 
• Explain the “fat-sparing” effect of glucose and how it relates to fat metabolism.  
  • As blood glucose levels rise, the use of lipids as an energy source is inhibited. This is because the increased blood glucose levels stimulate the release of insulin which tells cells to use glucose instead of lipids to produce energy. This results in decreased fat metabolism and increased carbohydrate metabolism.  
• Discuss the claims made by low-carbohydrate diets concerning weight loss and their associated challenges.   
  • Low carbohydrate diets can promote weight loss and overall health. These diets typically suggest that long-term weight loss is achieved through a reduction in dietary carbohydrates and glycemic load. However, a number of diet intervention studies have found that low-glycemic-load diets do not cause significantly greater long-term weight loss compared with higher-glycemic-load diets. However, the challenge with some research studies assessing the impacts of low carbohydrate diets on weight loss is that dietary protein is not controlled. If these studies do not control for protein intake, we have no way of knowing if protein is playing a role in the weight loss we see. Ultimately, there is currently little scientific evidence to support that low-carbohydrate diets are better than other diets in promoting weight loss.  
• What are some of the potential benefits and side effects of consuming foods and beverages made with sugar substitutes?  
  • The benefits are that they reduce the consumption of simple sugars, which are higher in calories, cause tooth decay and are linked to chronic disease. However, a common side effect is gastrointestinal upset as a result of their incomplete digestion. Studies have also shown that high artificial sweetener consumption is associated with increased CVD and cancer risk.  
• Provide examples of personal dietary choices that can assist individuals in meeting the Health Canada recommendations of eating more unrefined carbohydrates and fibres.   
  • Eat more fruits and vegetables with each meal. 
  • Get your daily carbohydrate servings from whole grains by eating whole-grain cereals or using whole-grain bread to make sandwiches, etc. 
  • Substitute refined white flour with whole-wheat or whole-grain flour.  
  • Add beans, nuts, or seeds to salads. 

Chapter 5. Lipids

• What are the three types of lipids and what roles do each play in the body?  
  • Triglycerides typically make up 95% of the lipids in our diet and provide our body with energy. 
  • Phospholipids are crucial for building the protective barrier, or membrane, around your body’s cells. Phospholipids are synthesized in the body to form cell and organelle membranes. In blood and body fluids, phospholipids form structures in which fat is enclosed and transported throughout the bloodstream. 
  • Sterols: cholesterol is the most well-known sterol and is important component of the cell membrane and is required for the synthesis of sex hormones, vitamin D, and bile salts 
• How does the degree of fatty acid saturation typically affect the state of fats at room temperature?  
  • Double carbon bonds in unsaturated fatty acids, cause kinks in the fatty acids, which makes it harder for them to pack together. On the other hand, saturated fatty acids tend to be straighter, making it easier for them to pack together.  Therefore, foods higher in saturated fatty acids tend to be solid at room temperature and foods rich in unsaturated fatty acids tend to be liquid at room temperature. 
• What is hydrogenation? How does this process alter the properties of fats?  
  • Hydrogenation involves adding hydrogen to the carbon double bonds, making the fatty acid appear more saturated (or less unsaturated in the case of partial hydrogenation). This process can change the state of fats (e.g., convert vegetable oils into semisolid fats).  
• Considering what you have learned about the health implications of eating saturated and unsaturated fats, what dietary adjustments can you make to eat healthier?  
  • If you decide to limit your intake of fat products, then choosing unsaturated fats may be more beneficial than choosing saturated fats. This choice is easy to make because unsaturated fats are usually liquid at room temperature while saturated fats tend to be solid at room temperature. However, there are some exceptions like avocados which are high in unsaturated fats and tropical oils (e.g., coconut oil) which are high in saturated fats.  
• What is the difference between essential and non-essential fatty acids and why is this distinction important to consider when planning your diet?  
  • Essential fatty acids must be obtained from food because they cannot be synthesized by the body, unlike non-essential fatty acids which the body is capable of synthesizing on its own.  
• What is the difference between the health benefits of eicosanoids derived from omega-3 fatty acids and eicosanoids omega-6 fatty acids?  
  • Eicosanoids derived from omega-6 fatty acids increase blood pressure and inflammation and cause blood clotting and immune responses. On the other hand, eicosanoids derived from omega-3 fatty acids are known to have heart-healthy effects. 
• What is unique about the structure of phospholipids? 
  • Their amphiphilic nature: the fatty acid sides are hydrophobic (dislike water) and the phosphate group is hydrophilic (like water). 
• What is the role of food emulsifiers? Provide some examples of food emulsifiers.   
  • Emulsifiers allow oil and water to mix. Without emulsifiers, the fat and water content within food would be somewhat separated. Lecithin found in egg yolk, honey, mayonnaise, and mustard is a common emulsifier. Emulsifiers enhance the appearance and freshness of food. 
• Why is it important for individuals to maintain healthy blood cholesterol levels?   
  • High cholesterol levels can form a large part of the plaque that narrows arteries in a process known as atherosclerosis.  
•  How do dietary choices influence cholesterol absorption?  
  • Consuming more plant sterols can contribute to lower cholesterol levels because they inhibit cholesterol absorption.  
•  How do fats move in a water-based environment despite their water-insoluble nature?  
  • Bile salts envelop the fatty acids and monoglycerides to form micelles. Micelles have a fatty acid core with a water-soluble exterior. This allows efficient transportation of fats to the intestinal microvillus. 
• What are the potential health implications of fat malabsorption?  
  • If fats are not absorbed properly as seen in some medical conditions, a person’s stool will contain high amounts of fat. Continued fat malabsorption can cause steatorrhea. Steatorrhea can result from diseases that affect absorption, such as Crohn’s disease and cystic fibrosis. 
• How does the body store and use triglycerides from food for energy production? 
  • After a meal, the triglycerides in the chylomicrons are moved to adipose or muscle cells. Capillary walls contain an enzyme called lipoprotein-lipase that dismantles the triglycerides in the lipoproteins into fatty acids and glycerol, allowing them to enter the adipose cells. The fatty acids and glycerol are then reassembled into triglycerides and stored for later use. Muscle cells may also take up the fatty acids and use them for muscular work and energy production. When a person’s energy requirements exceed the fuel available from a recent meal, or extended physical activity has exhausted glycogen energy reserves, fat reserves are retrieved for energy production. 
• What are the functions of lipids in the body? Briefly explain each function.  
  • Lipids are a major source of energy- 9 kcal/gram, especially during lower-intensity and longer-duration exercise. 
  • Lipids primarily function as an energy reserve. Fats are packed tightly together without water so you can store far greater amounts of energy in a reduced space. Fat cells are specialized for fat storage and can expand almost indefinitely in size. 
  • Lipids control the body’s internal climate and maintain a constant temperature. They also help the body produce and regulate hormones (e.g., adipose tissue secretes leptin, which regulates appetite). Lipids play an important role in brain activity, structure, and function and facilitate the signalling of electrical impulses throughout the brain. The lipids in cell membranes regulate what enters and exits the cell.   
  • Lipids play an important role in insulating and protecting the body from extreme temperatures and keeping the internal climate under control. Fat tissue pads our hands and buttocks and prevents friction because these areas frequently come into contact with hard surfaces. 
  • Lipids assist in digestion because by carrying fat-soluble nutrients throughout the digestive process, internal absorption is improved (increased bioavailability) 
• According to existing health guidelines, ideally, which types of fats should be consumed in higher amounts, and which should be limited?  
  • Consume the majority of fats from foods containing a high proportion of polyunsaturated and monounsaturated fats, such as those found in fish, nuts, and vegetable oils. 
  • Consume fewer than 10 percent of calories from saturated fats.  
  • Keep the consumption of trans fats (any food label that reads hydrogenated or partially hydrogenated oil) to a minimum, less than 1 percent of calories. 
• What are the major lipoproteins and what are their functions?  
  • VLDLs: transport triglycerides from the liver to various tissues in the body. As the VLDLs travel through the circulatory system, the lipoprotein lipase strips the VLDL of triglycerides and they become intermediate-density lipoproteins. 
  • IDLs: transport a variety of fats and cholesterol in the bloodstream. While travelling in the bloodstream, cholesterol is gained from other lipoproteins while circulating enzymes strip its phospholipid component. When IDLs return to the liver, they are transformed into low-density lipoproteins. 
  • LDLs: commonly known as the “bad cholesterol”. LDLs carry cholesterol and other lipids from the liver to our tissues throughout the body. Each cell’s surface has receptor systems specifically designed to bind with LDLs. Circulating LDLs in the bloodstream bind to these LDL receptors and are consumed. Once inside the cell, the LDL is taken apart and its cholesterol is released. In liver cells, these receptor systems aid in controlling blood cholesterol levels as they bind the LDLs. A deficiency of these LDL binding mechanisms will leave a high quantity of cholesterol travelling in the bloodstream, which can lead to heart disease or atherosclerosis. 
  •  HDLs: carry cholesterol out of the bloodstream and into the liver, where it is either reused or removed from the body with bile. They are called the “good cholesterol.” 
• List and explain the potential adverse health consequences of high blood lipid levels.   
  • Cardiovascular disease: the arteries thicken and harden with plaque buildup, causing restricted or at times low or no blood flow to selected areas of the body. 
  • Heart attack: when blood flow to a section of the heart is cut off due to a blood clot.  
  • Ischemic stroke: when a blood vessel in the brain or leading to the brain, becomes blocked, again usually from a blood clot. If part of the brain suffers a lack of blood flow and/or oxygen for three minutes or longer, brain cells will start to die. 
  • Congestive heart failure: the heart is not pumping blood as well as it should. The heart is still working but it is not meeting the body’s demand for blood and oxygen. If left unchecked, it can progress to further levels of malfunction. 
  • Arrhythmia: This is an abnormal rhythm of the heart. The heart may beat above one hundred beats per minute (known as tachycardia) or below sixty beats per minute (known as bradycardia), or the beats may be irregular. The heart may not be able to pump enough volume of blood to meet the body’s needs. 
  • Heart valve problems: Stenosis is a condition in which the heart valves become compromised in their ability to open wide enough to allow for proper blood flow. Some times heart valves do not close tightly, and blood begins to leak between chambers. 
  • Obesity: the excessive accumulation of body fat. Obesity has been linked to increased risks of developing diabetes and heart disease.  

Chapter 6. Proteins

• How are over hundred thousand different proteins produced in the body?   
  • Different proteins are produced because twenty types of naturally occurring amino acids are combined in unique sequences to form polypeptides. The abundant variations of proteins are due to the unending number of amino acid sequences that can be formed. 
• Describe and explain the basic steps of protein synthesis.  
  •  The first step in constructing a protein is the transcription of the genetic information in DNA into RNA. Next, during translation, the RNA instructs the cells to gather all the necessary amino acids and add them to the growing protein chain in a very specific order. The third step in protein production involves folding it into its correct shape. Specific amino acid sequences contain all the information necessary to spontaneously fold into a particular shape.  
• Describe the four structural levels of proteins. 
  • Primary: The first level is the one-dimensional sequence of amino acids that are held together by peptide bonds.  
  • Secondary: The second level of protein structure is dependent on the chemical interactions between amino acids, which cause the protein to fold into a specific shape, such as a helix or sheet. 
  • Tertiary: The third level of protein structure is three-dimensional. As the different side chains of amino acids chemically interact, they either repel or attract each other, resulting in a folded structure.  
  • Quaternary:  The fourth level of structure is achieved when protein fragments called peptides combine to make one larger functional protein.  
• What is protein denaturation? How does this process affect the structural and chemical properties of proteins?  
  •  Denaturation is physical changes seen in a protein exposed to abnormal conditions in the environment such as heat, acid, high salt concentrations, alcohol, and mechanical agitation. When a protein denatures, its complicated folded structure unfolds, and it becomes just a long strand of amino acids again. The weak chemical forces that hold tertiary and secondary protein structures together are broken and since proteins’ function depends on their shape, denatured proteins are no longer functional. 
• Why do proteins make you feel full for longer than carbohydrates?  
  • Protein digestion in the stomach takes longer than carbohydrate digestion, so eating a high-protein meal increases the amount of time required to sufficiently break down the meal in the stomach. This means that the food stays in the stomach for longer, making you feel full for longer.  
• What are the two major pancreatic enzymes that digest proteins?  
  • Chymotrypsin and trypsin.
• How are amino acids recycled to make new proteins?  
  • Every day, over 250 grams of protein are recycled to make 250 grams of new protein. To form these new proteins, amino acids from food and those from protein destruction are placed into a “pool.” When an amino acid is needed to build another protein, it can be acquired from the existing amino acids in the body. This is why it is important to maintain amino acid levels within this pool by consuming high-protein diets because if amino acid levels are not maintained, amino acids in the pool will be obtained by increasing protein destruction from other tissues in the body such as muscle.  
• How are dietary proteins catabolized for energy production, and what are the overall health implications of protein catabolism?  
  • Only about 10% of dietary proteins are catabolized make cellular energy every day. The liver breaks down amino acids to the carbon skeleton, which can then be fed into the citric acid cycle. This is similar to the way that glucose is used to make ATP. If a person’s diet does not contain enough carbohydrates and fats, their body will use more amino acids to make energy, which compromises the synthesis of new proteins and destroys muscle proteins. 
• How might daily protein recommendations vary among different groups (e.g., the elderly and athletes)?
  • Elderly: as we age, our muscle mass gradually decreases in a process known as sarcopenia. Approximately half the population of men and women above the age of 80 are sarcopenic, and studies have shown that higher intakes (1.2-1.5 g per kg of body weight) may prevent aging adults from becoming sarcopenic.  
  • Athletes: The body requires protein post-exercise so that you can build bigger, stronger, and healthier muscle tissue after intense exercise like strength training. The daily protein recommendations for strength athletes are 1.6-1.7 g/kg of body weight per day. Some strength athletes may need up to 2.2 g/kg of body weight per day. Athletes should consume protein from high-quality sources, such as dairy, eggs, lean meats. However, eating an excessive amount of protein at one time does not further stimulate muscle-protein synthesis. In fact, it is recommended that after a training session, athletes should consume 0.25-0.4 g/kg of body weight of protein in their post-exercise meal. If strength athletes do not complete sessions that include exercise to failure, they should consume this protein within one hour after exercise to enhance muscle protein synthesis. However, if the athlete’s session includes exercise to failure, this window may extend up to 24 h post-exercise.  
• What are the health consequences of protein deficiencies and high-protein diets?
  • There are two main syndromes associated with protein deficiencies: Kwashiorkor and Marasmus. Kwashiorkor is characterized by swelling (edema) of the feet and abdomen, poor skin health, growth retardation, low muscle mass, and liver malfunction. The primary symptoms of Kwashiorkor include not only swelling, but also diarrhea, fatigue, peeling skin, and irritability. Marasmus affects mostly children below the age of one in low-income countries. It is characterized by an extremely emaciated appearance, poor skin health, and growth retardation. The symptoms are acute fatigue, hunger, and diarrhea. 
  • Some studies suggest that diets high in animal protein, especially red meat, are linked to a higher risk for kidney stones, kidney disease, liver malfunction, colorectal cancer, and osteoporosis. However, diets that include lots of red meat are also high in saturated fat and cholesterol and are sometimes linked to unhealthy lifestyles, so it is difficult to say that high-protein causes these unfavourable health consequences. High-protein diets can however restrict other essential nutrients like vitamin and mineral intakes and result in other potential cardiac, renal, bone, and liver abnormalities.  
  • It’s important to remember that moderation is key.
• Reflecting on what you’ve learned about protein supplements and their effectiveness, what is your perspective on integrating them into your dietary routine or fitness regimen? How would you weigh the pros and cons of protein supplements?    
  • From what we’ve learned, it’s safe to assume that there isn’t sufficient evidence to support that protein and amino acid supplements are superior to regular food in enhancing exercise performance. Choosing high quality protein foods will help you build muscle, and this is also a lot more affordable than buying supplements to meet your protein goals. If you do choose to buy protein (e.g., whey protein) and use it to make a protein shake post workout, it is important to remember that there is no need to add more than what is required to obtain 0.25-0.4g /kg of body weight. Protein shakes and protein bars might be a good idea for endurance or strength athletes who have little time to make a nutritious exercise recovery snack. It is still important to do your research on the protein snacks/supplements you buy and to read the label as some have high amounts of carbohydrates from added sugars and aren’t the best protein sources for athletes.  

Chapter 7. Metabolism

• How is energy classified? Provide examples of each type of energy being used in our daily lives.  
  • Energy is classified as either potential or kinetic. Potential energy is stored energy, or energy waiting to happen. Kinetic energy is energy in motion. An example of this is riding your bike. When your bike is parked on top of a hill, it has potential energy. When you are riding your bike down the hill, you have kinetic energy.  
• How do carbohydrates, proteins, and fats differ in their energy content per gram?  
  • 9 kcal/g of lipids.
  • 4 kcal/g of carbohydrates and proteins.
• What are nutrient-dense foods and do they relate to food quality?  
  • High-quality foods are nutrient-dense, meaning they contain lots of nutrients relative to the number of calories/energy they provide. They are the opposite of empty-calorie foods such as sugary carbonated drinks which contain a lot of calories and very little, if any, nutrients.  
• What is the difference between catabolism and anabolism?  
  • Metabolism includes both catabolism and anabolism. Catabolism is the process of molecule breakdown into smaller molecules, and it releases energy. Anabolism refers to the process of building bigger molecules from smaller molecules and it requires energy.  
• Compare fat and carbohydrate stores in humans.  
  • Humans have larger stores of fat compared to carbohydrates. Fat is a better alternative to glycogen for energy storage as it is more compact and, unlike glycogen, the body does not store water along with fat. Water weighs a significant amount, and increased glycogen stores would dramatically increase body weight due to the increased water content.  
• What would happen to chemical reactions without enzymes?  
  • Enzymes are catalysts- they speed up chemical reactions and reduce the energy required to complete the chemical reaction. Without enzymes, chemical reactions would take much longer to happen and would use up too much energy for life to exist.  
• How are metabolic pathways involved in catabolism and anabolism regulated by energy status?  
  • All cells are in tune with their energy balance.  When energy levels are high, cells join smaller molecules into larger ones via energy-requiring anabolic pathways and when energy levels are low, catabolic pathways are initiated to release energy, in which bigger molecules are broken down into smaller molecules.  
• What happens to pyruvate in the presence and absence of oxygen?  
  • In the absence of oxygen (anaerobic), pyruvate is converted to lactic acid, which is known as fast glycolysis. In the presence of oxygen (aerobic), and if a cell is in negative-energy balance, pyruvate is transported to the mitochondria where it first gets one of its carbons cleaved off, yielding acetyl-CoA. It can then go to the citric acid cycle and the electron transport chain/oxidative phosphorylation to make more energy.  
• Why is some energy released as heat during nutrient catabolism?  
  • Heat is a vital product of nutrient catabolism and is involved in maintaining body temperature. If heat was not produced as this byproduct human body temperature would significantly drop, and they would die of hypothermia. This is why nutrient catabolism is only 30-40% efficient.  

Chapter 8. Introduction to Micronutrients

• Compare the storage sites and absorption of water-soluble and fat-soluble vitamins.  
  • Fat-soluble vitamins are absorbed along with dietary fat so if a meal is very low in fat, the absorption of fat-soluble vitamins will be impaired. Once fat-soluble vitamins have been absorbed in the small intestine, they are packaged and incorporated into chylomicrons along with other fatty acids and transported in the lymphatic system to the liver. Water-soluble vitamins on the other hand are absorbed in the small intestine but are transported to the liver through blood vessels. 
• Why do water-soluble vitamins need to be consumed more regularly than fat-soluble vitamins?  
  • Fat-soluble vitamins are mainly stored in our adipose tissue, which means that we don’t need to consume them daily.  We do not typically store water-soluble vitamins (except B12), so they need to be consumed regularly. 
• How did Fiji’s government combat the national iodine deficiency? What government policies can be implemented to address the present-day mineral deficiencies in Canada?  
  • The government of Fiji banned non-iodized salt and allowed only fortified iodized salt into the country in hopes of increasing the consumption of iodine in people’s diets. The Canadian government can also set forth a fortification policy to enhance the nutritional quality of certain foods. For example, if vitamin D is still a common deficiency despite milk being fortified with vitamin D in Canada, the vitamin D content can be doubled. This is just one example.  
• How are minerals classified as major minerals and trace minerals? 
  • Trace minerals are classified as minerals required in the diet each day in smaller amounts (100 milligrams or less). Major minerals are classified as minerals that are required in the diet each day in amounts larger than 100 milligrams. 
• How does mineral bioavailability differ between plant-based and animal-based foods? Why is this the case?  
  • Plant-based foods often contain factors, such as oxalate and phytate, that bind to minerals and inhibit their absorption. In general, minerals are better absorbed from animal-based foods. For example, the absorption of calcium from vegetables and nuts is lower than that from milk because the oxalate in plant-based foods binds to the calcium and affects absorption. 
• How does chemical form affect nutrient bioavailability? Provide an example.  
  • Heme iron, found in meats, fish, and poultry, is better absorbed than non-heme iron from plant and animal sources, iron-fortified foods, and supplements.   
• What is the relationship between vitamin intake and mineral absorption? Provide an example.   
  • Certain vitamins can enhance mineral absorption. For example, vitamin D boosts calcium and magnesium absorption.  

Chapter 9. Micronutrients for Energy

• Why is the lack of inclusivity in the existing micronutritional guidelines problematic?   
  • Existing nutritional guidelines offer clear recommendations for males and females, but no guidelines exist for transgender or non-binary people. This is problematic because studies have shown that transgender people who have had gender-affirming surgery or hormone therapy have different nutritional needs than those who have not. There isn’t enough research to inform recommendations for transgender and non-binary people and this can cause confusion and negative health outcomes for them, especially if they aren’t meeting their micronutrient needs.  
• What are the effects of thiamin deficiency on the cardiovascular and nervous systems?   
  • The brain and heart are most affected by a thiamin deficiency. Thiamin deficiency, also known as beriberi, can cause symptoms of fatigue, confusion, movement impairment, pain in the lower extremities, swelling, and heart failure. Wernicke- Korsakoff syndrome can cause similar symptoms as beriberi such as confusion, loss of coordination, vision changes, hallucinations, and may progress to coma and death. This condition is specific to alcoholics.  
• How does riboflavin assist in the energy production process? 
  • Riboflavin is an essential component of flavoproteins, which are coenzymes involved in many metabolic pathways of carbohydrate, lipid, and protein metabolism (e.g., Krebs cycle). Riboflavin also aids in the transfer of electrons in the electron transport chain and helps fight oxidative damage.  
• What is the role of food packaging in preventing ariboflavinosis?  
  • Riboflavin is destroyed by light, so foods containing riboflavin should be stored in dark or opaque containers to prevent ariboflavinosis.  
• How do diets high in tryptophan influence niacin synthesis? What role, if any, do these diets play in preventing niacin deficiency?   
  • Niacin can be synthesized by humans from the amino acid tryptophan. Niacin is made from tryptophan only after tryptophan has met all of its other needs in the body. The contribution of tryptophan-derived niacin to niacin needs in the body varies and a few scientific studies have shown that diets high in tryptophan have very little effect on niacin deficiency. 
• What are the potential risks associated with niacin supplementation?   
  • Supplementation can cause toxicity, which can result in burning, tingling, itching, and flushing on the face, arms, and chest. When very large doses are taken over long periods of time, liver damage, glucose intolerance, blurred vision, and edema of the eyes may occur.  
• Although a pantothenic acid deficiency is exceptionally rare, how might this deficiency disrupt the metabolism of lipids, carbohydrates, and proteins?  
  • Pantothenic acid forms coenzyme A, which is the main carrier of carbon molecules in a cell. Acetyl-CoA is the carbon carrier of glucose, fatty acids, and amino acids in the citric acid cycle. Therefore, pantothenic acid deficiency can disrupt the production of coenzyme A, and disrupt fatty acid, glucose, protein, and ketone metabolism. 
• Explain how vitamin B6 deficiency leads to anemia. How is this type of anemia different from those caused by deficiencies in folate, cobalamin, or iron?  
  • Vitamin B6 is also a required coenzyme for the synthesis of hemoglobin and so a deficiency in vitamin B6 can cause anemia, but it different than that caused by insufficient folate, cobalamin, or iron, although the symptoms are similar. The size of red blood cells is normal or somewhat smaller, but the hemoglobin content is lower. This means each red blood cell has a decreased oxygen-carrying capacity, resulting in muscle weakness, fatigue, and shortness of breath. 
• How does geographic location influence the iodine content in foods? 
  • The mineral content of foods is greatly affected by the soil from which it grew and since iodine comes mostly from seawater, the greater the distance from the sea, the lesser the iodine content in the soil.  
• How do low iodine levels affect growth and development?   
  • Low iodine levels result in hypothyroidism which negatively affects all stages of growth and development. The thyroid hormone plays a major role in brain development and growth, and fetuses and infants with severe iodine deficiency develop a condition known as cretinism, in which physical and neurological impairment can be severe. 
• How did residential school nutrition experiments contribute to vitamin deficiencies?   
  •  Indigenous peoples were used as experimental subjects to test nutrition requirements in malnourished children. The effects of federal underfunding led to unqualified staff members and poor kitchen facilities. This resulted in diets lacking vitamins A, B, and C and iodine due to inadequate portions of milk, fruits vegetables, eggs, and cheese being served to the children.  

Chapter 10. Micronutrients Involved in Fluid and Electrolyte Balance

• What is the process of osmoregulation? 
  •  Osmoregulation is the control of fluid balance and composition in the body. The processes involved keep fluids from becoming too diluted or too concentrated. To maintain water balance, a cell controls the movement of electrolytes to keep the total number of dissolved particles the same inside and outside. The total number of dissolved substances is the same inside and outside a cell, but the composition of the fluids differs between compartments. 
• What is the difference between hypertonic, hypotonic, and isotonic solutions?  
  • Hypertonic: where a cell is placed in a more concentrated solution and water moves from inside the cell to the outside, causing it to shrink. 
  • Hypotonic: where a cell is placed in a solution that contains fewer dissolved particles than the cell itself and water moves into the more concentrated cell, causing it to swell.
  • Isotonic: when a solution contains an equal amount of dissolved particles on either side of the membrane.
• Why is water called the universal solvent?  
  • Water is called the universal solvent because more substances dissolve in it than in any other fluid. Molecules dissolve in water because of the hydrogen and oxygen molecules’ ability to loosely bond with other molecules. 
• Explain how the body regulates blood pressure via the renin-angiotensin-aldosterone system.  
  • When the concentration of solutes in the blood increases, an anti-diuretic hormone is released from the pituitary gland, which subsequently increases water resorption by the kidneys, thus increasing blood volume and blood pressure.  When blood volume and blood pressure are low, the kidneys secrete renin. Renin activates angiotensin, which is then converted to angiotensin 1 and then angiotensin 2. Angiotensin 2 causes vasoconstriction of the blood vessels, which increases blood pressure. Angiotensin 2 also causes the adrenal glands to secrete aldosterone, which causes the resorption of sodium and chloride, and an increase in water retention and a decrease in urine output. 
• Why is water an ideal medium for chemical reactions? 
  • Water is an ideal medium for chemical reactions as it can store a large amount of heat, is electrically neutral, and has a pH of 7.0, meaning it is not acidic or basic. Additionally, water is involved in many enzymatic reactions as an agent to break bonds or to form bonds. 
• Considering the protective role mucus plays in the body, how might disruptions in its production impact the body’s overall health?  
  • With disruptions in mucus production, our body would not be able to expel nasal irritants or perform essential functions such as transporting nutrients and eliminating waste products. We need mucus to act as a frontline defense and shield tissues from irritants, trap pathogens, and combat harmful invaders. We also need mucus to breathe properly.  
• Explain how the temperature set point of the body is maintained even when exposed to cooling temperatures.  
  • When we feel cold, the hypothalamus sends a signal to smooth muscle tissue surrounding blood vessels, causing them to constrict and reduce blood flow. This reduces heat lost to the environment. The hypothalamus also sends signals to muscles to erect hairs and shiver, and to endocrine glands like the thyroid to secrete hormones capable of ramping up metabolism. These actions increase heat conservation and heat production.  
• How do increased blood sodium concentrations drive us to drink water? Explain the steps involved in this process.   
  • Receptor proteins in the kidney, heart, and hypothalamus detect decreased fluid volume or increased sodium concentration in the blood. 
  • Hormonal and neural messages are relayed to the brain’s thirst center in the hypothalamus. 
  • The hypothalamus sends neural signals to higher sensory areas in the cortex of the brain, stimulating the conscious thought to drink. 
  • Fluids are consumed to increase water input.  
  • Receptors in the mouth and stomach detect mechanical movements involved with fluid ingestion. 
  • Neural signals are sent to the brain and the thirst mechanism is shut off. 
• Explain how the nervous and endocrine system interact to regulate water output.   
  • The kidneys detect blood volume. Kidneys have protein sensors that detect blood volume from the pressure, or stretch, in the blood vessels of the kidneys. When blood volume is low, kidney cells detect decreased pressure and secrete the enzyme renin.  
  • The hypothalamus detects blood osmolality. In response to a high sodium level, the hypothalamus activates the thirst mechanism and concurrently stimulates the release of antidiuretic hormone. 
• Sally is training to participate in an ultramarathon in extremely hot weather. What are some things Sally can do to prevent dehydration, hyponatremia, and heat stroke?  
  • To prevent dehydration, Sally should make sure she is wearing light and breathable clothes and keeping herself hydrated with water and electrolytes throughout the ultramarathon. By doing so, she will also be preventing the risk of heatstroke. To prevent hyponatremia, she should also make sure she isn’t overhydrating either and only drinking as much water as she needs.  
•  Which populations may benefit from lowering their salt intake? Why? How can this be achieved using salt substitutes and alternative seasonings? 
  • Individuals with prehypertension or hypertension would especially benefit from lowering their salt intake because studies have shown that reducing salt intake prevents hypertension and is also helpful in reducing blood pressure once hypertension is diagnosed. This can be done by using salt substitutes which replace sodium with potassium, Mrs. dash and Spike or alternative seasonings such as curry powder, chives, allspice, lemon juice, etc.   
• What are the functions of potassium in the body? 
  • Potassium is required for fluid balance. Potassium is involved in nerve impulse, protein synthesis, energy metabolism, platelet function, acts as a buffer in blood, and plays a role in acid-base balance.  
• What are common dietary sources of chloride? 
  • Dietary sources of chloride include table salt, tomatoes, lettuce, olives, celery, rye, whole-grain foods and seafood. Many salt substitutes are sodium-free but still contain chloride.   
• Which individuals may be at risk of experiencing phosphorous toxicity? What are some of the observable signs of phosphorous toxicity and how can this be prevented?  
  • Those with kidney disease or those who are taking too many vitamin D supplements or phosphorus-containing antacids may be at risk. Very high blood levels of phosphorus can result in muscle spasms and convulsions. Phosphorous toxicity can be prevented by not taking too many phosphorous-containing antacids and only consuming the recommended intake of vitamin D, especially in supplement form.  
• The DASH-Sodium trial investigated the effects of a specified eating plan with or without reduced sodium intake. The results of the study showed that following the DASH diet reduced blood pressure among participants. Why is it that the reductions in blood pressure cannot be attributed to decreases in salt intake alone?    
  • The DASH diet is an eating plan that is low in saturated fat, cholesterol, and total fat. Following the DASH diet not only reduces sodium intake, but also increases potassium, calcium, and magnesium intake. All of these electrolytes are known to reduce blood pressure, so the reductions in blood pressure seen in individuals following the DASH diet cannot be attributed to decreases in salt intake alone.  

Chapter 11. Micronutrients as Antioxidants

• What are free radicals? How do antioxidants reduce the potential damage caused by excessive free radicals? 
  • Stable atoms have an even number of electrons orbiting in pairs in their outer shell. When an atom loses an electron during oxidation, typically, reduction will occur to stabilize the unpaired electron. However, in some cases, the electrons remain unpaired and these highly reactive molecules are known as free radicals. Free radicals can cause cell damage and oxidative stress. However, antioxidants can reduce this potential damage by donating an electron to a free radical, thus stabilizing the unpaired electron.  
• What are the functions of vitamin E? 
  • Vitamin E helps to protect and prevent the oxidation of polyunsaturated fatty acids, LDLs, red blood cell membranes, and lung cells. It also boosts the immune system and enhances the dilation of blood vessels and inhibition of blood clotting, and it plays an important role in the development of muscles, nerves, and blood cells.  
• How do vitamin E deficiencies contribute to feelings of weakness and fatigue? 
  • Vitamin E plays a critical role in the development of red blood cells. When a Vitamin E deficiency occurs, red blood hemolysis and anemia can occur, which affects oxygen transport and causes weakness and fatigue.  
• How can you maximize your vitamin C intake from foods? 
  • Since vitamin C is water-soluble, it leaches away from foods during cooking, freezing, thawing, and canning. Because of this, it is recommended to eat fruits and vegetables raw or lightly steamed to maximize your vitamin C intake.  
• What is the most definitive sign of a vitamin A deficiency? Why? 
  • Retinol that is circulating in the blood is taken up by cells in the eye retina, where it is converted to retinal and is used to help the pigment rhodopsin, which is involved in the eye’s ability to see under low light conditions. A deficiency in vitamin A results in less rhodopsin and a decreased ability to see under low-light conditions. This is why night blindness is the most definitive sign of a vitamin A deficiency.  
• What are some of the signs and symptoms of selenium toxicity? How can this be prevented? 
  • Selenium toxicity can cause brittle nails and hair, gastrointestinal discomfort, skin rashes, halitosis, fatigue, and irritability. Selenium toxicity can be prevented by following the age group-specific dietary reference intakes and by ensuring you do not consume doses greater than 400 mcg per day as that is the upper limit.  
• What role do antioxidants play in cancer prevention?
  • Antioxidants enhance the immune system, inhibit the growth and proliferation of cancerous cells, and prevent oxidative DNA cell damage. 
• What role, if any, does vitamin E play in atherosclerosis prevention? 
  • LDLs, when oxidized, contribute to the formation of plaques in the arteries, leading to atherosclerosis and cardiovascular diseases. The antioxidant properties of vitamin E were hypothesized to prevent atherosclerosis by reducing the oxidation of low-density lipoproteins. However, there is currently conflicting evidence regarding the antioxidant effect of vitamin E in preventing cardiovascular disease. Instead, there is more consistent evidence from observational studies suggesting that a higher intake of vitamin E results in a lower risk of dying from a heart attack.  
• What is the primary difference between dry and wet forms of age-related macular degeneration? 
  • The dry form of AMD involves the formation of deposits in the macula, which can lead to gradual vision loss, but may not immediately impair vision in the early stages. In contrast, the wet form of AMD is characterized by abnormal blood vessel growth in the macula, leading to more rapid and severe vision loss. The wet form is less common but more serious than the dry form. 
• Does taking vitamin C prevent colds?  
  • There is not enough evidence to support that vitamin C prevents colds. However, a recent review has shown that taking vitamin C routinely can reduce cold severity and duration. 

Chapter 12. Micronutrients for Bones

• List and explain the various functions of the skeletal system.  
  • The skeleton allows for multiple types of movement, and it provides structural support and protection for all the other organ systems in the body. Red and white blood cells and platelets are synthesized in the bone marrow. Another vital function of bones is that they act as a storage depot for minerals such as calcium, phosphorous, and magnesium. Bones also contain a complex network of canals, blood vessels, and nerves that allow for nutrient transport and communication with other organ systems.  
• Explain the role of bone remodelling in maintaining bone health across one’s lifespan, and outline the steps involved in bone remodelling.   
  • Bone tissue contains many different cell types that constantly resize and reshape bones throughout growth and adulthood. Bones are continuously growing and changing shape in the process of modelling where bone tissue is dismantled at one site and built up at a different site. In adulthood, our bones stop growing and modelling, but continue to go through a process of bone remodelling. 
  • The first step in bone remodelling is osteocyte activation. Osteocytes detect changes in mechanical forces, calcium homeostasis, or hormone levels. In the second step, osteoclasts are recruited to the site of the degradation and dissolve minerals in the bone tissue matrix in a process called bone resorption. In the third step of bone remodelling, sugars and proteins accumulate along the bone’s surface, forming a cement line which forms a strong bond between the old bone and the new bone that will be made. In the last step of bone remodelling, osteoblasts lay down new osteoid tissue that fills up the cavities that were excavated during the resorption process and the bone tissue begins to mineralize.  
• How does dietary calcium intake affect bone health?  What happens when blood calcium levels are low?  
  • Blood calcium levels are rigorously controlled so that if blood levels drop, the body will rapidly respond by stimulating bone resorption and by releasing stored calcium into the blood.  This means that bone tissue sacrifices its stored calcium to maintain blood calcium levels. This is why we need to meet our daily recommended intake of calcium to maintain bone health and strength. When your diet is calcium deficient, the mineral content of bone decreases causing it to become brittle and weak. Increased calcium intake helps increase the mineralized content of bone tissue. Greater mineralized bone tissue corresponds to a greater BMD and greater bone strength.  
  • Blood calcium is closely regulated by PTH, calcitriol, and calcitonin. When blood calcium levels are low, PTH is secreted to increase blood calcium via increased bone resorption, increased calcium reabsorption in kidney cells and decreased calcium excretion in the urine. PTH also stimulates enzymes to activate vitamin D to calcitriol, which also increases calcium absorption. 
• Which factors influence calcium bioavailability, and how do they impact dietary recommendations?   
  • The body doesn’t completely absorb all the calcium in food. The calcium in some vegetables such as kale, brussel sprouts, and bok choy is better absorbed by the body than dairy products. An adequate intake of vitamin D enhances calcium bioavailability while chemicals that bind to calcium decrease its bioavailability.  Oxalates are found in high concentrations in spinach, parsley, cocoa, and beets. In general, the calcium bioavailability is negatively related to the oxalate content in foods. High-fibre, low-fat diets also decrease the amount of calcium absorbed. Additionally, although there isn’t sufficient evidence to support this yet, it is said that high consumption of other minerals at the same time (i.e. iron, zinc, magnesium) can decrease calcium absorption. With that being said, you might want to make dietary adjustments such as increasing your vegetable (e.g., kale, brussel sprouts) and vitamin D intake and decreasing your intake of oxalates for example to maximize calcium absorption.   
• Why is the RDA for calcium elevated for adults above the age of 50? 
  • As we get older, stomach acidity sometimes decreases, diarrhea occurs more often, kidney function is impaired, calcium absorption in the gut decreases, vitamin D3 activation is reduced,  and vitamin D absorption and activation are compromised, all of which contribute to a decrease in calcium bioavailability. It is really important for adults over the age of 50 to maintain adequate blood calcium levels to prevent accelerated bone tissue loss, especially during menopause. This is why the RDAs are higher.  
• Explain the role of vitamin D in regulating blood calcium levels and promoting bone health.  
  • Activated vitamin D3 regulates blood calcium levels and bone health in conjunction with parathyroid hormone by regulating calcium and phosphorus absorption in the small intestine. In the absence of an adequate intake of vitamin D, less than 15 percent of calcium is absorbed from foods or supplements. Vitamin D can also maintain blood calcium levels by working with the kidney to excrete more or less calcium in the urine. Vitamin D also stimulates osteoclasts to break down bone when calcium is needed elsewhere in the body. 
• What is the role of vitamin K in wound healing? 
  • Vitamin K is critical for blood function acting as coenzymes which play an essential role in blood clotting. Blood-clotting proteins are continuously circulating in the blood. Upon injury to a blood vessel, platelets stick to the wound forming a plug. This means that without vitamin K, blood would not clot. 
• Which individuals are most at risk of experiencing phosphorous toxicity?  
  • Those with kidney disease or those who are taking too many vitamin D supplements or phosphorus-containing antacids may be at risk of experiencing phosphorous toxicity.  
• What are the health benefits of magnesium beyond bone health maintenance?  
  • More than three hundred enzymatic reactions require magnesium. Magnesium plays a role in protein synthesis and repair, the synthesis of DNA and RNA, carbohydrates, and lipids, and is essential for nerve conduction and muscle contraction. Another health benefit of magnesium is that it may decrease blood pressure.  
•  Explain how socioeconomic challenges may increase the incidence of tooth decay among certain communities in Canada.  
  • Fluoride is added to drinking water in 45% of communities in Canada and in British Columbia, only 3.7% of the population has access to fluoridated water. This means that not everyone has access to fluoridated water. Fluoride is known to combat tooth decay and fluoridation in water can prevent ~20-40% of cavities in children and adults but it is expensive and not accessible to all. This means that individuals who don’t have access to this water may be at greater risk of fluorosis.  Fluoridation of water prevents, on average, 27 percent of cavities in children and between 20 and 40 percent of cavities in adults, however, it can be expensive. 
•  How might vitamin deficiencies contribute to the development of bone diseases, such as osteoporosis, and how can they affect the quality of life and independence among older adults? How might lifestyle changes mitigate the risk of developing such bone diseases?   
  • Bone diseases such as osteoporosis are affected by dietary influences such as low calcium and vitamin D intake. Osteoporosis results in decreased bone mineral density and the disruption of bone architecture. It is associated with an increased fracture risk as bones become more brittle and weak, especially among older populations. Repeated fractures may cause vertebral compression and reduced height, which can negatively affect one’s quality of life and independence. These adults may not be able to perform their activities of daily living without assistance due to fear of falling and experiencing a fracture. Lifestyle changes such as increased physical activity can strengthen the bones and reduce the risk of future fractures. Weight-bearing and balance training exercises can also reduce fall risk in older adults.  

Chapter 13. Nutrition and Physical Activity

• What is physical activity?   
  • Physical activity is any movement produced by the muscles that increases energy expenditure. This physical activity can occur in 4 domains: occupational, household, leisure-time, and transportation. 
• How have the cumulative effects of colonization and modernization influenced the physical activity behaviours of Indigenous peoples today?  
  • Traditionally, Indigenous peoples participated in many sports and physical activities as part of ceremonial dances or food-sourcing practices (e.g., hunting, fishing, etc). However, the effects of colonization stripped Indigenous peoples of their cultural identities and replaced many of these traditional hunting/harvesting practices and sports with Euro-Canadian sports. Additionally, the effects of modernization have also led to changes in these practices. People don’t need to spend as much time in nature even if they wish to participate in cultural hunting because they can easily drive to their destinations, which reduces their physical activity participation.  
• What are the physical and emotional benefits of increased physical activity participation?  
  • Longer life: A regular exercise program can reduce your risk of premature death from heart disease, certain cancers, and other leading causes of death. 
  • Cardiovascular disease prevention: Being active boosts HDL cholesterol and decreases unhealthy triglycerides, which reduces the risk of cardiovascular diseases. 
  • Management of chronic conditions: A regular routine can help prevent or manage a wide range of conditions and concerns, such as metabolic syndrome, type 2 diabetes, depression, arthritis, and certain types of cancer. 
  • Energy boosts: Regular physical activity can improve muscle tone and strength, and provide a boost to your cardiovascular system. 
  • Strong bones: Research shows that aerobic activity and strength training can slow the loss of bone density that typically accompanies aging. 
  • Improved physical fitness: This allows us to carry out daily life activities with vigour and without undue fatigue, and allows us to enjoy leisure-time pursuits. 
  • The mental and emotional benefits include mood improvements, reduced risk/symptoms of depression, cognitive skills retention (improved thinking, learning, and judgement as you age), and better sleep patterns.  
• Design a strength program for an individual looking to improve their muscular fitness without access to a gym membership/equipment. Include frequency, duration, and modes of exercise in your answer.  
  •  I would design a strength program in which the individual exercises for ~45-60 mins at least twice a week to improve muscle strength and bone strength. 
  • Since they don’t have access to a gym, I can include body weight/resistance band exercises such as pull-ups, push-ups, leg squats. I can also have them use homemade weights such as plastic bottles filled with sand for progressive overload once they feel comfortable with bodyweight exercises.   
• Pretend you are a healthcare professional working with a sedentary client looking to improve their cardiorespiratory fitness level. What exercise recommendations would you make to this client? Be specific in terms of exercise intensity, frequency, type, and duration. How might you assess pre- and post-intervention changes in their cardiorespiratory fitness?  
  • I would prescribe 150 minutes of moderate-intensity aerobic exercise as this individual is a beginner to exercise. I would have them exercise for 30 minutes 5 days a week and have them engage in exercises such as walking, jogging, or biking. If they have access to a gym, they can use the elliptical, treadmill, or even the rowing machine. It’s important to remember that moderate-intensity is not the same for everyone, so it is crucial to assess their starting CRF levels to know which mode of exercise to prescribe. I can do this by having them complete a VO2max test before they start the exercise program and at the end of the program again to assess improvements in their CRF level.  
• How do exercise intensity and duration influence substrate utilization?   
  • Both anaerobic and aerobic metabolism combine during exercise to ensure that the muscles are equipped with enough ATP to carry out the demands placed on them. The amount of contribution from each type of metabolism will depend on the intensity of the activity. When low-intensity activities are performed, aerobic metabolism is used to supply enough ATP to muscles. However, during high-intensity activities, more ATP is needed so muscles must rely on both anaerobic and aerobic metabolism to meet the body’s demands. During higher intensity and shorter duration exercise, carbohydrates are the primary energy source to produce energy really quickly. During lower intensity and longer duration exercise, fatty acids are the predominant fuel source to produce larger amounts of energy.  
• How can endurance athletes avoid “hitting the wall”?  
  • Endurance athletes can load up on carbohydrates for a few days before the event.  This is called carbohydrate loading and it will maximize an athlete’s amount of glycogen stored in their liver and muscle tissues. Endurance athletes can also consider ingesting carbohydrates in events longer than approx. 45 minutes.  
• Why is carbohydrate loading not beneficial to all athletes? 
  • If you are not preparing for a longer duration endurance event, you will not need to increase muscle glycogen stores as these likely won’t be emptied during your event. If you are not an endurance athlete exercising for more than 90 minutes, carbohydrate loading will provide no benefit.  
• How might societal pressures influence energy intake and disordered eating patterns?  
  • Society creates unrealistic expectations for women and men and contributes to body image issues, eating disorders, and nutritional deficiencies. For example, there is increased pressure for females to be thin in society currently and because of this, some females take exercising too far. This low energy intake may lead to nutritional deficiencies and even the female athlete triad which can cause bone loss, stoppage of menstrual periods, and eating disorders.  
•  Say you are an endurance athlete competing in a 2-hour event. What should your carbohydrate intake look like before, during, and following the event?   
  • For events longer than 90 minutes, athletes may benefit from carbohydrate loading of 10-12 g/kg of body weight 36-48 h prior to the endurance event. 1-4 h before exercise, they should consume a fairly large meal containing 1-4 g/kg of body weight of carbohydrates and maybe even 25-30 g of carbohydrates 30-60 min before the event.  
  • During the event, they should consume high GI foods or mouth rinse with carbohydrates during exercise. Since it is 2h long, they should consume 30-60 g of carbohydrates per hour during the event. 
  • After the event, they should consume high GI foods to promote glycogen synthesis 2 h post-exercise and consume 1.2 g/kg of body weight of carbohydrates per hour for the next 4 hours.  
• What is hyponatremia? What are some of its causes and common signs? How can hyponatremia be avoided?  
  • During long endurance exercises such as a marathon or triathlon, sodium losses are larger and must be replenished.  If water is replenished without sodium, the sodium already present in the body will become diluted. These low levels of sodium in the blood will cause hyponatremia. In order to avoid hyponatremia, athletes should increase their consumption of sodium in the days leading up to an event and consume sodium-containing sports drinks during their race or game. The early signs of hyponatremia include nausea, muscle cramps, disorientation, and slurred speech.  

Chapter 14. Health at Every Size

• How have the effects of urbanization and technological advancements contributed to the growing rates of obesity worldwide?  
  • The fast-food industry has been growing for decades. In Canada today, there are over 14,000 McDonald’s restaurants, while in 1967, there was only one. Food portions have also been getting bigger. Escalators, elevators, and horizontal walkways now dominate shopping malls and office buildings, factory work has become increasingly mechanized and robotized, the typical Canadian watches more than four hours of television daily, and in many workplaces, the only tools required to conduct work are a chair and a computer. These factors contribute to unhealthy dietary habits and also increase sedentary behaviour while reducing physical activity participation.  
• What are the harmful effects of weight bias and stigma? What strategies can be employed to reduce weight-based discrimination in healthcare settings?  
  • Weight-biased discrimination in clinical/healthcare settings can negatively affect the clinician-patient relationship and result in poorer delivery of care for patients dealing with obesity. Individuals who experience weight-based discrimination are also more likely to engage in maladaptive eating behaviours and spend more time living sedentary/physically inactive lifestyles. They are also more susceptible to experiencing mental health issues such as mood disorders and other poor health outcomes.  
• How might you debunk the common misconception that obesity is the result of personal choices alone?   
  • Students can provide different examples here (e.g., genetic, socioeconomic influences, etc). 
  • I will use genetics as an example: research studies have established a link between genetic and epigenetic factors and obesity. Maternal exposure to harmful chemicals and toxins such as cigarette smoking can produce chemical modifications in genes, increasing the risk of offspring obesity. Additionally, studies have shown that not everyone responds to exercise in the same way. There are responders and non-responders. Some people may not lose any weight after following an exercise program while others may note significant weight loss. This goes to show that body weight is not completely under personal control.  
• Sally is a 21-year-old female. She weighs 55 kg and is 1.57 m tall. Calculate Sally’s BMI. What BMI category does Sally fall under?  
  • 55/(1.576^2)= 22.1 
  • Normal weight 
• Why should BMI not be used as a standalone method for accurately assessing disease risk?  
  • BMI does not take into account fat mass or fat distribution in the body, which are both additional predictors of disease risk. Body fat weighs less than muscle mass. Because of this, BMI can sometimes underestimate the amount of body fat in overweight or obese people and overestimate it in more muscular people. 
• Why might someone experience difficulty losing weight despite being physically active?   
  • Research has consistently demonstrated that exercise alone is not an effective method for experiencing weight loss. The current physical activity guidelines recommend that individuals meet 150 minutes of moderate to vigorous-intensity exercise per week. However, ACSM states that up to 60 minutes of moderate to vigorous-intensity exercise per day is needed when relying on exercise alone for weight reduction. 
  • Additionally, inter-individual differences affect one’s capacity for weight loss in response to exercise interventions. While some individuals achieve clinically significant weight loss, others may experience either minimal to no changes in body weight or even experience some weight gain in response to exercise training without caloric restrictions. 
• Reflecting on what you have learned about the relationship between cardiorespiratory fitness and all-cause mortality risk, discuss what is more important: weight loss or increased physical activity participation?  
  • Studies have established that CRF is a better indicator of all-cause mortality risk than body weight or BMI. We also know that increased physical activity/exercise participation does not guarantee weight loss but it does guarantee improvements in one’s cardiometabolic health profile (i.e. improved cardiorespiratory fitness (CRF), glucose control, endothelial function, lipoprotein particle size, high-density lipoprotein, and overall improved quality of life).  
  • Studies have also shown that reduced fat does not equate to fitness because weight loss achieved through liposuction did not reduce one’s CVD risk or improve their cardiometabolic health profile. If body weight truly was the core problem, then liposuction would have produced favourable health outcomes (i.e. improved glucose control, endothelial function, etc). However, it is not body weight but the increased sedentary behaviour and low physical activity levels that contribute to the increased morbidity and mortality rates. This is why we need to shift our focus to increasing physical activity participation rather than focusing so much on body weight.  
• Why might the current Canadian Society for Exercise Physiology 24-hour movement guidelines/ACSM physical activity guidelines not apply to South Asian populations?   
  • SACs are most susceptible to developing diabetes and diabetes-related risk factors due to their higher deposition of visceral adipose tissue and lower PA levels. They also have higher body fat percentages than White Canadians of similar BMI. This is influenced by factors such as their genetically unfavourable cardiometabolic health profiles (high cholesterol, triglyceride, and glucose tolerance), socio-cultural barriers, and inherently lower CRF levels. Because of this, studies have shown that SACs should engage in a total of 230 minutes of moderate to vigorous-intensity aerobic exercise/week to achieve the same cardiometabolic health improvements as White Europeans engaging in 150 minutes of moderate to vigorous-intensity aerobic exercise.  
  • It’s also important to consider that the current exercise guidelines derive from studies that use White European men as participants, which limits their applicability to SACs and possibly other ethnic groups.  
• How do the effects of childhood undernutrition extend beyond one’s lifespan? How do the intergenerational effects of residential school malnutrition affect Indigenous communities today?   
  • The infants born to women who develop obesity and chronic diseases as a result of childhood hunger are more susceptible to experiencing intrauterine growth failure, abnormal birth weight, and faltering growth. These infants also face an increased risk of developing insulin resistance and type II diabetes through their childhood and adolescent years. Researchers further investigating these intergenerational effects have observed elevated BMI and obesity rates among the adult grandchildren of the famine survivors, thus suggesting that the effects of childhood undernutrition can be transmitted to even the third generation of exposed individuals. This means that the descendants of residential school survivors (up to the third generation) could face elevated BMI and obesity rates because of the effects of hunger and malnutrition experienced by their grandparents for example.    
• Explain how you can use the small-change approach in your personal life to improve your overall health and fitness levels.   
  • This answer will be different for everyone.  
  • One might say that they can use the small-change approach to add small amounts of activity to my daily life. I can walk an additional 2000 steps every day, and instead of driving to work every day, I can bike or walk to work occasionally to increase my physical activity levels.