NUTR1023 Lecture Notes - Lecture 3: Dietitian, Recall Bias, Nutrient
Module 3
Objectives
L1 - Dietary guidelines
Dietary guidelines are developed with 2 main purposes:
•provide guidance on the food and diet patterns that achieve optimal intake of essential nutrients in our
diet
•Protect us from different chronic diseases
The current guidelines are made from an extensive review of evidence and consultation from stakeholders
•55000 scientific journal articles consulted in the review of evidence
5 key statements of current dietary guidelines
To achieve an maintain a healthy weight, be physically active and chose amounts of nitrites foods and
drinks to meet your energy needs.
Enjoy a wide variety of nutritious foods from these five groups every day
•Vegetables
•Fruit
•Grains
•Meat and alternatives
•Diary and alternatives
Limit intake of foods containing saturated fat, added salt, added sugars and alcohol
Encourage, support and promote breastfeeding
Care for your food, prepare and store It safely
Limitations of the guidelines
• they are general and dont provide specific guidance on the amount of specific foods
The guidelines also come with the Australian Guide to Healthy Eating that gives an idea about the propor-
tion of food groups to eat every day
Nutrient reference values
Another set of guidelines that provide specific recommendations on how much of each nutrients we
should be consuming in different population groups
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find more resources at oneclass.com
The different reference values for different nutrients:
EAR (estimated average requirement)
•A daily nutrient level estimated to meet the requirements of half of the healthy imdividuals in a particu-
lar life stage and gender group
RDI (recommended daily intake)
•average daily intake that is sufficient to meet the nutrient requirements of nearly all (97-98%) healthy in-
dividuals in a particular life stage and gender group.
•Set at much high than the EAR to cover nearly all requirements
AI (adequate intake)
•the average daily nutrient intake level based on observed and experimentally derived approximations of
nutrient intake by a group of apparently healthy people that are assumed to be adequate.
•AI is used when the RDI cannot be determined
EER (estimated energy requirement)
•average dietary intake that is predicted to maintain energy balance in a healthy adult of defined age,
gender, weight, height and level of physical activity, consistent with good health.
•In children and pregnant women, the EER is taken to include the needs associated with the deposition of
tissue or the secretion of milk at rates consistent with good health.
UL (upper level of intake)
•the highest average daily nutrient intake likely to posses no adverse health effects to almost all individu-
als in the general population.
•As intake increase above the UL, the potential of risk of adverse effects increases
AMDR (acceptable macronutrient distribution range)
•the estimate of the range of intake for each macronutrient for individuals (expressed as percentage con-
tribution to energy) which would allow for an adequate intake of all other nutrients whilst maximising
general health outcomes.
SDT: suggested dietary target
•a daily average intake from food and beverages for certain nutrients that may help in prevention of
chronic diseases
•Rather than just meet the requirements, this includes extra intake targeted at preventing chronic disease
The modelling system used to form the guidelines to healthy eating
1. Identifying the usually intake of different foods and food groups
2. What nutrients would be consumed based on the usual intake of foods
3. Running simulated models with different diet patterns to see whether the diet patterns would cover
the RDI for 10 key nutrients within acceptable energy intake for different ages and gender
4. Series of total diet models could be developed
5. The models are translated to recommendations into different food groups
The guiding principles for the revision was that the guidelines should:
•address total diet and overall health
•Be evolutionary (incremental changes), flexible and practical
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find more resources at oneclass.com
•Be based on Current scientific evidence
The goal of the modelling system is to translate the NRV (2006) into food consumption patterns that
concurrently:
•deliver the nutrient requirements for people of varying age and gender, activity levels and life stages
•Are culturally acceptable and reflects diet of different socio economic groups
•Take into account the current Australian food supply and food consumption patterns
•Provide some flexibility in food choices
•Promote health and wellbeing
L2 - Dietary assessment
The purpose of dietary assessments is to measure the food and nutrient intake of individuals and populations in order
to identify any pertinent nutrient issues. We can only do dietary patterns based on a given period of time (like 24 hour
recall etc) but not over many years.
Types of assessment models
• 24h recall
• Food records
• Diet history
• Food frequency or questionnaire
• Short questions
The methods used should be dependent to which group of individuals you are trying to assess the diet of. Also the re-
sources available.
Strengths and limitations of the assessment models
24 hr recall
• participant required to recall all food for past 24 hours
• Inexpensive and quick
• Can assess usual intake in large populations especially
• Multiple 24 hr recall is needed for each individual because you want the average 24 hour consumption instead of the
intake of one special day
Limitations:
• Recall bias or forgetfulness
• Omission of foods not eaten frequently
• The wording of the interviewer can have a huge influence because saying “what did you eat in the past 24 hours” is
different to saying “what do you eat in a typical 24 hour period”
Food records
• Considered one of the more accurate methods of diet
• prospective record of food recorded as they are eaten
• Weighed food records more accurate
• Done over like 3-7 days
Limitations
• can be expensive and time consuming
• Potential for behavioural changes by participants, because they are aware of their intake being recorded and will try
to eat better things.
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Dietary guidelines are developed with 2 main purposes: provide guidance on the food and diet patterns that achieve optimal intake of essential nutrients in our diet, protect us from different chronic diseases. The current guidelines are made from an extensive review of evidence and consultation from stakeholders: 55000 scientific journal articles consulted in the review of evidence. To achieve an maintain a healthy weight, be physically active and chose amounts of nitrites foods and drinks to meet your energy needs. Enjoy a wide variety of nutritious foods from these five groups every day: vegetables, fruit, grains, meat and alternatives, diary and alternatives. Limit intake of foods containing saturated fat, added salt, added sugars and alcohol. Care for your food, prepare and store it safely. Limitations of the guidelines: they are general and dont provide specific guidance on the amount of specific foods.
