1. BMS208 Topic 1: An overview of Nutrition Chris Blanchard
23/02/2019
BMS208 Human Nutrition
Topic 1: An overview of Nutrition
Chris Blanchard
Topic 1

2. Objectives Discuss the major reasons people make food choices.
BMS208
23/02/2019
Objectives
Discuss the major reasons people make food choices.
List the six nutrients contained in food and a major use of each nutrient.
Identify the energy-providing nutrients and calculate the energy available from foods.
List the types of research designs and the strengths and weaknesses of each.
Discuss Dietary Reference Intakes (DRI) and the 4 parts of the DRI including the Estimated Average Requirements (EAR), Recommended Dietary Allowances (RDA), Adequate Intakes (AI), and Tolerable Upper Intake Levels (UL).
Explain the Estimated Energy Requirement (EER) and how it is used to maintain energy balance.
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3. BMS208
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Objectives (cont’)
Discuss the Acceptable Macronutrient Distribution Ranges (AMDR) and how they relate to a healthy diet.
Utilize the DRI in the assessment of a healthy individual.
List the 4 parts of a nutritional assessment and apply them to individuals to detect malnutrition.
List the major methods used to survey the nutritional status of populations.
Identify the chronic diseases that are linked to diet or alcohol.
Identify accurate sources of nutrition information.
List the 8 red flags that identify nutrition misinformation.
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4. Food Choices Personal preference (eg taste,texture, spicy)
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Food Choices
Personal preference (eg taste,texture, spicy)
Habit (eg cereal in the morning)
Ethnic heritage or tradition (eg meat pies in Australia)
Social interactions (eg coffee shop)
Availability, convenience and economy (time poor)
Positive and negative associations (sporting events, upbringing)
Emotional comfort (boredom, depression)
Values (religion, environmental)
Body weight and image
Nutrition and health benefits (functional foods)
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5. Nutrients in Foods Provide: Energy Structural material
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Nutrients in Foods
Provide:
Energy
Structural material
Regulating agents to support growth
Maintenance and repair of body tissues 5
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6. Nutrients in Foods (cont’)
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Nutrients in Foods (cont’)
Composition of Foods
Water
Carbohydrates (CHO), protein, lipid
Vitamins, minerals
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7. BMS208
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Body Composition
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8. Nutrients Chemical composition Essential Nutrients
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Nutrients
Chemical composition
Inorganic – minerals and water
Organic – CHO, lipids, proteins, vitamins
Essential Nutrients
Must be in diet – eg vitamins
Non Essential and Conditionally Essential
Body can generally make these from dietary precursors
Other compounds in foods
Phytochemicals
Non-nutrients
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9. Energy Yielding Nutrients
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Energy Yielding Nutrients
Units:
Calories, Joules
1 kCal = 4.2 kJ
Carbohydrates – 16.8 kJ/g
Proteins – 16.8 kJ/g
Lipids – 37.7 kJ/g
Alcohol – not a nutrient – 29.4 kJ/g
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10. Vitamins Organic Do not provide energy 13 different vitamins
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Vitamins
Organic
Do not provide energy
13 different vitamins
Numerous specific activities eg:
Assist with night vision
Assist in blood clotting
Vulnerable to destruction by heat, light etc
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11. Minerals Inorganic Do not provide energy 16 known to be essential
Indestructible
Can be lost during refining and cooking

12. Water Inorganic Does not provide energy
Provides environment for reactions in the body
Participates in metabolic reactions
Medium for transporting materials within the body

13. The Science of Nutrition
Study of nutrients and other substances in food and how the body handles them
Relies on disciplines such as biology, biochemistry, physiology, chemistry, molecular biology, statistics etc
Important that nutrition research is “robust”

14. Conducting research Identify a problem Develop a hypothesis
Undertake research that will prove or disprove this hypothesis
If Hypothesis is supported develop a theory

15. Conducting Research (cont’)
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Conducting Research (cont’)
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16. Conducting Research (cont’)
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Conducting Research (cont’)
Subjects
Experimental group (receive treatment)
Control group (don’t receive treatment)
Randomized: so they have an equal chance of receiving the treatment
Sample size
Needs to be large enough to make results statistically significant
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17. Conducting Research (cont’)
Placebo
Beneficial affect when subject thinks they are receiving a treatment
Blind experiment: subjects don’t know if they are receiving the treatment
Double blind: both researchers and subjects don’t know who are receiving the treatments

18. Analysing research findings
Accumulation of evidence can support a theory
Data may suggest a correlation between two or more variables
Correlation can be positive or negative
However, correlations do not prove theories
Mechanisms need to be demonstrated to obtain proof

19. Publishing Research Types of publications: Peer review
Peer reviewed eg scientific journals
Non-peer reviewed eg industry journals, web
Peer review
Ensures research is valid

20. Types of Research Designs
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Types of Research Designs
Epidemiological studies
Determine incidence of disease in a population
Can narrow down possible causes
Cannot prove cause and effect
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21. Types of Research Designs (cont’)
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Types of Research Designs (cont’)
Laboratory Based studies
Explore effects of a specific variable in vitro or in vivo
Can control conditions
Difficult to apply in vitro or animal results to humans 21
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22. Types of Research Designs (cont’)
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Types of Research Designs (cont’)
Human intervention or clinical trials
Uses humans as subjects
Can control some conditions and apply to other human settings
Cannot generalise to all humans
Ethical issues 22
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23. Dietary Reference Intakes
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Dietary Reference Intakes
Set of nutrient intake values
Resulted from thousands of research studies
Values can be found on the inside front cover of your textbook
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24. Nutrient recommendations
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Nutrient recommendations
Estimated Average Requirement (EAR) defines the requirement of a nutrient that supports a specific function in the body for half of the healthy population.
Recommended Dietary Allowances (RDA) use the EAR as a base and include sufficient daily amounts of nutrients to meet the known nutrient needs of practically all healthy populations. This recommendation considers deficiencies.
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25. Nutrient recommendations
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Nutrient recommendations
Adequate Intakes (AI) reflect the average daily amount of a nutrient without an established RDA that appears to be sufficient.
Tolerable Upper Intake Level (UL) is a maximum daily amount of a nutrient that appears safe for most healthy people and beyond which there is an increased risk of adverse health effects. 25
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26. Energy recommendations
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Energy recommendations
Estimated Energy Requirement (EER) represents the average daily energy intake to maintain energy balance and good health for population groups.
Acceptable Macronutrient Distribution Range (AMDR) represents the range of intakes for energy nutrients that provide adequate energy and nutrients and reduce risk of chronic disease.
Carbohydrates: 45 – 65 % kCalories
Fat: 20 – 35 % kCalories
Protein: % kCalories
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27. Nutrition Assessment Results of too much or not enough nutrients:
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Nutrition Assessment
Results of too much or not enough nutrients:
Undernutrition: become thin, loose muscle tissue, become prone to disease
Malnutrition: diarrhoea, rashes, fatigue
Overnutrition: heart disease, diabetes
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28. BMS208
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Nutrition Assessment
To prepare a nutritional assessment the following are considered:
Historical information
Anthropometric data
Physical examinations
Laboratory tests 28
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29. Historical information
Health status
Socio-economic status
Drug use
Diet
Medical record (disease state)
Family history
Marital status
Ethnic background
Educational background

30. Anthropometric data
Measure: Height and weight
Compare to standards

31. Physical examination Signs of poor nutrition can be found in: Hair
Eyes
Skin
Posture
Tongue
Fingernails

32. Laboratory tests Analyse samples: Compare to standard levels Blood
Urine
Compare to standard levels

33. Stages in development of a nutrient deficiency

34. Diet and Health Diet is closely related to health
Lack of nutrients lead to chronic disease
Eg lack of vit C causes scurvy
Excess of nutrients also leads to chronic disease
Eg heart disease, diabetes etc

35. Nutrition assessment of populations
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Nutrition assessment of populations
National nutrition surveys
National monitoring program
Integration of two major national surveys:
collects data on kinds and amounts of foods people eat
examines the people themselves using anthropometric measurements, physical examinations and laboratory tests
National health goals
Identifies the nation’s health priorities
National trends
Demonstrate how has our eating has changed with time
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36. Nutrition information and misinformation
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Nutrition information and misinformation
Use of the internet as a source of information
Nutrition in the news
Nutrition experts
Identifying fake credentials
“Red Flags” of nutrition quackery
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37. Use of the internet as a source of information
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Use of the internet as a source of information
Choose your information sources carefully
Professional organisations
Peer reviewed articles
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38. Nutrition in the news Beware of trusting information from the news
Often biased
Mislead to create confusion
Preliminary reports often premature
Tight deadlines lead to lack of depth
Need for catchy headlines

39. Identifying experts
Accredited dieticians are the best source of advice
Don’t assume all health professionals have adequate training
Always check credentials

40. Red flags of nutritional quackery
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Red flags of nutritional quackery
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