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

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. Topic 1

BMS208 23/02/2019 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. Topic 1

Food Choices Personal preference (eg taste,texture, spicy) BMS208 23/02/2019 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) Topic 1

Nutrients in Foods Provide: Energy Structural material BMS208 23/02/2019 Nutrients in Foods Provide: Energy Structural material Regulating agents to support growth Maintenance and repair of body tissues 5 Topic 1 5

Nutrients in Foods (cont’) BMS208 23/02/2019 Nutrients in Foods (cont’) Composition of Foods Water Carbohydrates (CHO), protein, lipid Vitamins, minerals Topic 1

BMS208 23/02/2019 Body Composition Topic 1

Nutrients Chemical composition Essential Nutrients BMS208 23/02/2019 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 Topic 1

Energy Yielding Nutrients BMS208 23/02/2019 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 Topic 1

Vitamins Organic Do not provide energy 13 different vitamins BMS208 23/02/2019 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 Topic 1

Minerals Inorganic Do not provide energy 16 known to be essential Indestructible Can be lost during refining and cooking

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

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”

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

Conducting Research (cont’) BMS208 23/02/2019 Conducting Research (cont’) Topic 1

Conducting Research (cont’) BMS208 23/02/2019 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 Topic 1

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

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

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

Types of Research Designs BMS208 23/02/2019 Types of Research Designs Epidemiological studies Determine incidence of disease in a population Can narrow down possible causes Cannot prove cause and effect Topic 1

Types of Research Designs (cont’) BMS208 23/02/2019 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 Topic 1 21

Types of Research Designs (cont’) BMS208 23/02/2019 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 Topic 1 22

Dietary Reference Intakes BMS208 23/02/2019 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 Topic 1

Nutrient recommendations BMS208 23/02/2019 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. Topic 1

Nutrient recommendations BMS208 23/02/2019 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 Topic 1 25

Energy recommendations BMS208 23/02/2019 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: 10- 35 % kCalories Topic 1

Nutrition Assessment Results of too much or not enough nutrients: BMS208 23/02/2019 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 Topic 1

BMS208 23/02/2019 Nutrition Assessment To prepare a nutritional assessment the following are considered: Historical information Anthropometric data Physical examinations Laboratory tests 28 Topic 1 28

Historical information Health status Socio-economic status Drug use Diet Medical record (disease state) Family history Marital status Ethnic background Educational background

Anthropometric data Measure: Height and weight Compare to standards

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

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

Stages in development of a nutrient deficiency

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

Nutrition assessment of populations BMS208 23/02/2019 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 Topic 1

Nutrition information and misinformation BMS208 23/02/2019 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 Topic 1

Use of the internet as a source of information BMS208 23/02/2019 Use of the internet as a source of information Choose your information sources carefully Professional organisations Peer reviewed articles Topic 1

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

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

Red flags of nutritional quackery BMS208 23/02/2019 Red flags of nutritional quackery Topic 1