Human Nutrition Unit 1 Notes PDF

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Human Nutrition Unit 1 Notes Provided Notes Textbook Notes inside Notebook

Definitions 

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Food – any solid or liquid matter consumed by a living organism that maintains life and growth o Supplies energy, supplies nutrients o Can be processed or raw Nutrients – substances the body uses for growth, maintenance and repair of its tissues o 6 classes of nutrients  Split into 2 groups: Group A -Energy providing and Group B – other nutrients (non-energy containing)

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Group A Group B 1. Carbohydrates 1. Water 2. Fat 2. Vitamins 3. Protein 3. Minerals Can be essential, conditionally essential, or non-essential  Essential Nutrients – the nutrients that the body cannot make for itself from other raw materials. o Ex) essential fatty acids, linoleic acid, linolenic acid  Conditionally Essential Nutrients – nutrients that they body cannot make enough to meet the requirements of health  Ex) amino acid histidine during periods of growth  Non-Essential Nutrients – nutrients the body can make for itself  Do not rely on our food intake  Ex) some amino acids and some fatty acids

Measuring Food Energy 

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Food energy is measure in calories o Expressed as 1,000 calorie units – kilocalories (kcalories)  Commonly referred as calories Calorie - the amount of heat required to raise the temperature of one liter of water by one degree Celsius The amount of energy provided depends on the content of carbohydrates, fats, and protein Carbohydrates = 4 Cal/g (=kcal/g) Fat (lipid) = 9 Cal/g Protein = 4 Cal/g Alcohol = 7 Cal/g (not a nutrient)

How to Calculate the Energy Available from Foods 

Multiple grams of carbohydrates by 4, protein by 4, and fat by 9. Add the results together.

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Ex) 1 slice of bread with 1 tablespoon of peanut butter on it contains 16 grams of carbohydrate, 7 grams of protein and 9 grams of fat. o 15g carbohydrates x 4 kcal/g = 64 kcal o 7g protein x 4 kcal/g = 28 kcal o 9g x 9kcal/g = 81 kcal o Total = 173 kcal

How to Calculate Percentage Of kcal For Each Nutrient  

In relation to total kcal from the nutrients Divide kcal of nutrient by total kcal o Ex) 1 slice of bread with 1 tablespoon or peanut butter on it contains 16g of carbohydrates, 7g of protein, and 9g of fat, and 173 kcal o For fat:  9g of fat x 9kcal/g =81 kcal  81 kcal / 173 kcal = 0.468 x100 = 46.8% of calories in the peanut butter and bread are from fat o For protein:  7g x 4kcal/g = 28 kcal  28 kcal/ 173kcal = 0.162 x100 = 16.2%

Phytochemicals        

Found in plant foods Non-nutrient compounds derived from plants Have biological activity in the body May support health beyond the roles of traditional nutrients Play a role in the sensory qualities of food May act as antioxidants May mimic hormones May alter blood constituents to protect against disease processes o Ex) cancer, heart disease

Supplementing Phytochemicals   

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Can be naturally occurring in food or added Added phytochemicals may produce effects very different from those seen in whole foods o Can be harmful Before taking check: o Does it work o Is it safe o Has the FDA or Health Canada issued warnings o Is it inline with nutrition guidelines Have the potential to alter body functions, sometimes powerfully, in ways only partially understood The beneficial effects cannot be attributed to one individual photochemical Food, not supplements, is currently the most effective and safest source of phytochemicals

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Insufficient evidence whether they are effective at fighting disease or safe to consume in concentrated doses

Functional Food 

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Are products that may look like or be a conventional food and are consumed as a part of a usual diet, but have physiological benefits or can reduce the risk of chronic disease beyond basic nutritional functions Ex) Soy-based foods o Regular consumption of foods containing soybean has been shown to reduce the risk of developing hypertension Ex) Cranberry juice o Contain a phytochemical that may dislodge bacteria from the urinary tract o For UTI prevention recommend doses of 90 – 480ml (3-16 ounces) of cranberry cocktail twice daily or 15-30ml of unsweetened 100% cranberry juice daily are given o Concentrated cranberry tablets may significantly increase risks of kidney stones o Cranberry has not been shown effective as a treatment for documented UTI Ex) Yogurt o Contains probiotics (live bacteria that may provide health benefits)  Ex) lactobacillus organisms o Probiotics may improve diarrhea that accompanies the use of antibiotic drugs o May benefits some chronic intestinal diseases  Chron’s, colon cancer, ulcer, and irritable bowel syndrome o As well as reducing urinary and yeast infections in women, and lower blood cholesterol  More research needs to be done for these and the above claims

Nutraceuticals    

Products isolated or purified from food Generally sold in a medicinal form not usually associated with food Have physiological benefits or provide protection from chronic disease Ex) isoflavones (phytochemical) from soybeans can be extracted and sold in pill form. Isoflavone mimic those of hormones such as estrogen

Definition of Food Science  

Food science is an interdisciplinary field of science which overlaps other areas, such as nutrition, biology, chemistry, physics, and even engineering. Food science is the study of: o Raw food materials o Behaviour of raw food materials when created, processed, stored, packaged, and evaluated as consumer food products

Definition of Food Technology   

Applying food science to the: selection, preservation, processing, packaging, distribution, use of safe, nutritious, wholesome food The foods we typically consume have been affected by technology Technology allows for the wide availability and variety of foods

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o Ex) we can purchase canned, pickled, frozen, fresh, or dried vegetables and fruit o Ex) We can get foods in different types of packaging Technology affects our processed foods through the use of food additives o Such as emulsifiers that help the fat to bind to watery food components  Ex) mayonnaise o Such as colour stabilizers in the food or preservatives that help to keep the food fresh

Safety and Quality of Food  

Food science considers all safety and quality aspects of food before consumed Such as: o Food processing and manufacturing o Food preservation and packaging o Food safety and wholesomeness o Food distribution o Consumer food use and preparation

Definition of Food Scientist  

Applies scientific knowledge and technological principles to the study of foods and food components Can work in research or manufacturing

Food Science and Nutrition Research   

It is important to find, read and assess previous research that has been done on the topic in question Peer-reviewed literature is the gold standard for scientific information o Ex) PubMed, MEDLINE, and EBSCOhost Research Study Designs o 1. Descriptive studies: can generate a hypothesis, can focus on an individual or a population  Populational / correlational study  Researchers compare data from entire populations to identity factors that might influence the incidence of a disease in various populations o Impossible to establish causality since the whole population is being examined  Also referred to as epidemiological studies  Case report  Detailed report on a single patient  Case series  A compilation of multiple case reports  Cross-sectional survey  Examines both exposure and disease in individuals o 2. Analytical Studies: can test specific hypothesis, can include observational and intervention studies  Case-control study

Researchers compare people who have a given condition such as a disease with other people who do not have the disease. They closely match them in age, gender, and other key variables so that differences in other factors stand out. Cohort study  Classifies participants based on exposure and follows them for a period of time to assess disease development Intervention study  Researchers ask people to adopt a new behaviour (ex take a vitamin c supplement) and compare their results to the control group taking a placebo.  These trials help determine the effectiveness of such interventions in the development or prevention of disease.  Intervention studies are usually randomized (participants are randomly assigned to either the treatment or placebo group)  With a double-blind design, neither the researchers nor the study participants know who is receiving the treatment and who is receiving the placebo and are considered to provide the most compelling outcomes 

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Food Choices 

Factors that play a role in food choices: o Availability: rural areas may have less accessibility to some foods than urban communities o Cost: is the food affordable? o Convenience: if you need to eat your meat at school or on the run, does the food meet that need? o Emotional factors: ex) ice cream after a break-up o Social factors: ex) wing night with friends o Media advertising: a commercial makes you hungry, kids commercials – marketing unhealthy food to kids through the use of cartoon characters o Habit: choosing familiar foods  Ex) eating cereal for breakfast because you have always eaten this for breakfast since you were a child o Positive or negative association: we tend to like foods that have happy associations and dislike foods with negative food associations  Ex) cake and ice cream at a birthday party  Ex) if you ate a food and then felt sick, you are more likely to avoid that food in the future o Personal values: may avoid eating certain foods because of personal beliefs/ values  Ex) may avoid red meat or may choose organic foods over conventionally grown products o Weight, health, nutritional value: choosing foods that we perceive to be “good for us” o Personal preference: choosing food because of taste

Occupation: can influence the pattern of eating that we follow  Ex) if we work shift work, we eat our meals at a different time o Cultural/ ethnic factors: every culture has typical foods and ways of preparing them. Food beliefs, customs, attitudes and taboos affect the diet and determine what foods are acceptable Ethnocentrism: the belief that one’s own pattern of behaviour is preferred over those of other cultures Cultural Relativism: an approach of understanding and accepting other cultures. Recognizing that values and beliefs can differ, based on culture, but that all are equal o

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Food Consumption Trends 

Agriculture and Agri-Food Canada have made predictions as to Canadian food trends that will been seen up to 2020: o 1) Aging Canadians  It is projected that there will be more seniors and fewer children in the Canadian population in 2020 then we have seen in past years. This will influence the types of food that there is demand for in the food population o 2) An Evolving Society  It is predicted that brand names will become less of a status symbol and will be used by consumers to express individuality. Other changes in society are also expected to affect food choices, including decreased family, environmental awareness, globalization, and participation in the workforce. o 3) Changing Meal Patterns  Food preparation is predicted to decline, with a shift towards small, frequent meals or snacks instead of three meals a day. This would result in a greater demand for more portable food options. o 4) Shifting Expenditures  If is forecasted that the decline in amount for disposal income spent on food will continue to 2020. This is expected to impact the frequency that Canadians visit restaurants. o 5) Food for Health  The most significant health conditions expected to drive food choices are obesity, heart disease, and diabetes. o 6) The Educated Consumer  Consumers will be more conscious of what is in their foods through label reading, with a focus on:  Zero trans-fats  Low sodium  High fibre / healthy carbohydrates  Reduced sugar  Allergen identification  Fortification  Health claims o 7) The New Face of Canada

As immigration into Canada continues to increase so will the influence on our food supply. We will see diversification, fusion and blending of cuisines, as well as easier access to unfamiliar food ingredients, cooking methods, and presentation styles. 8) No Trade-off for Convenience  Consumers will want it all. They will not be willing to make any sacrifices for convenience, so the pressure will be on food producers to create convenient forms of foods that are nutritious, great tasting, fresh, and varied (ethnic foods as well) 9) Veggies Anyone?  The consumption of non-meat meals is expected to increase among nonvegetarians. This is due to consumer focus on health, quick preparation and ethnic food options 10) Organic Foods  Organic food consumption is expected to increase 11) Small Indulgences  It is predicted that there will be an increased demand for gourmet foods and boutique brands of food. We could potentially see a shift from demand for big portions of cheap food to a demand for smaller portions of high quality, nutritious foods 12) Food Safety and Production Issues  Consumer confidence in foods will continue to influence their decision to purchase. Food borne illness, food additives, food processing techniques (like biotechnology and irradiation), ethics, country of origin and contaminants will all continue to be important to consumers. 

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Hunger and the Global Environment 

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1/5 people experiences chronic lack of food in the world and every two seconds, one person dies in the world because of starvation. o Due to lack of access to food not lack of food itself Famine: widespread and extreme scarcity of food in an area that causes starvation and death in a large portion of the population Food poverty: hunger occurring when enough food exists in an area but some of the people cannot obtain it because they lack money, are being deprived for political reasons, live in a country at war, suffer from other problems such as lack of transportation Food shortage: hunger occurring when an area of the world lacks enough total food its people Hunger: lack or shortage of basic foods needed to provide the energy and nutrients that support health World Food Supply: the quantity of food, including stores from previous harvests, available to the world’s people at a given time Food banks: facilities that collect and distribute food donations to authorized organizations feeding the hungry Food pantries: community food collection programs that provide groceries to be prepared and eaten at home

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Emergency kitchens: programs that provide prepared meals to be eaten on-site; often called soup kitchens Food insecurity: limited or uncertain access to foods of sufficient quality or quantity to sustain a healthy and active life. Access to foods of sufficient quality means that a person may have access to enough calories but not necessarily enough nutrients o Risk factors:  Anything that limits resources available for food acquisition  Ex) increase in non-food expenditures, under-employment, and poverty o Leads to hunger – a major health issue Food security: access by all people at all times to nutritionally adequate, safe, personally acceptable foods from normal food channels The four pillars of food security: o 1) Availability  Sufficient amount at all times, and variety at a reasonable cost. This is affected by time of year/season, civil conflict/war, food preservation, and supply o 2) Accessibility  Determined by entitlements (the bundle of resources needed to acquire food)  Affected by: o Market prices o Employment/funds o Production and marketing systems o Gender and power relations within the household o Education o Sanitation o 3) Adequacy  Provide nourishment  Affected by control over resources, nutrient content of the food/ quality, information about food/ nutrition o 4) Acceptability  Refers to food that is personally palatable, acquired by a socially acceptable means of obtaining food, and culturally appropriate

Hunger in Developed Countries  

Main cause of hunger in developed countries is food poverty Food cannot be obtained because of: o Lack of money: to buy nutritious food and pay for other necessities like housing, clothing, medications, utilities. Often food is the sacrifice made. o Political reasons: up to 80% of hungry children live in countries that produce surplus food, but the decisions of policy makers in those areas, largely determines who in the population has access to the food o Countries of war: food transportation may be limited. Also, have other concerns beyond hunger. o Lack of transportation: can they get to the store to access food?

Cannot afford: may be on welfare (prices have increased but welfare has stayed fairly constant) or may be part of working poor (not on welfare because working, but pay too low to meet needs) To stretch food supplies: o Skip meals or cut their portions o May be forced to break social rules:  Ex) beg from strangers, steal from markets, scavenge through garbage cans, may even harvest dead animals from roadside.  Can lead to dangerous food borne illness o May rely on foods with nutrient density, but high calorie density, so calorie needs are met, but not nutritional needs.  Inexpensive foods like white bread, mac and cheese, pastas.  Diet tends to be low in fruit and vegetables, milk products, and meats/protein. Large amounts of the global food supply are wasted at all stages of the agri-food system Most food loss in developed nations occurs in households and in the food retail and service sectors National food recovery programs involve the collection of wholesome foods for distribution to low-income people who are hungry which would otherwise have gone to waste Four common methods of food recovery are: o 1) Field Gleaning  Collecting crops from fields that either have already have been harvested or are not profitable to harvest o 2) Perishable food rescue or salvage  Collecting perishable produce from wholesalers and markets o 3) Prepared food rescue  Collecting prepared foods from commercial kitchens o 4) Non-perishable food collection  Collecting processed foods from wholesalers and markets Local efforts: food recovery programs depend on volunteers. Concerned citizens work through local agencies and churches to feed the hungry o Ex) soup kitchens serve prepared meals o Ex) food banks: provide groceries and food. Food bank use in Canada is increasing o Ex) community kitchens are programs where individuals come together to prepare meals that they can take home to their families. Typical ingredients for set recipes are provided o Ex) community gardens are typically grown on donated plots of land, and typically the supplies and the seeds are donated to a community groups as well. The participants are responsible to care for the garden and benefit from the yield of produce o Ex) school feeding programs provide meals, such as breakfast and/ or lunch, to children at school o Ex) food share programs o

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World Hunger  

Food poverty is the primary cause of hunger in developing countries The “poorest poor” must manage with less than one dollar per day

A North American can gets more protein a day  People spend more on their cat per year than such a person makes a year Woman and children are usually the most affected Causes and Outcomes of Hunger: o Quantity, quality and availability of food  Ex) drought causing famine o Discrimination factors that affect distribution  Ex) war, government corruption o Individual household’s access to av...