Dietary guidelines and nutritional assessments Flashcards
Nutrition definiton
The process of nourishing or being nourished.
Also by which a living organism assimilates food and uses it for energy, growth and replacement of tissues
What messaging do the public currently get on nutrition in the UK
The Eatwell guide UK
What is the Eatwell guide
Tool used to define government recommendations on eating healthy and achieveing a balanced diet in a practical and consistent way
What does the eatwell guide look like
Plate with all the parts to a balanced diet and their proportions and food items
What are the individual requirements of each nutrients
- Age
- Gender
- Level of physical activity
- State of health
- Those who absorb or utilise nutrients less efficiently than others
What does DRV stand for
Dietary Reference Values
What are DRVs
Estimated dietary requirements for groups of the population in the UK
What does SACN stand for
Scientific Advisory Commitee on Nutrition
What are the 3 types of DRV estimates
- EAR
- RNI
- LRNI
What does EAR stand for
Estimated Average Requirements
What are EARs
Estimate of the average requirement of a nutrient used for energy
What does RNI stand for
Reference Nutrient Intake
What are RNIs
The amount of nutrients that is enough to ensure that the needs of all the group are being met
What does LRNI stand for
Lower Reference Nutrient Intakes
What are LRNI
The amount of a nutrient that is enough for only the small number of people who have low requirements (2.5%)
Where do LRNI, EAR and RNI sit on a bell curve
LRNI = Left
EAR = Middle
RNI = Right
How to use DRVs
- Assesses diets of a group
- Assess diets of individuals
- Prescribe diets/Food supply
- Labelling purpose
What are the limitations of DRVs (3)
- Only applies to healthy people
- Lack of consistency in different countries
- May not apply if deficiencies/excess exist
Why is there a lack of consistency (3)
- Different terminologies
- Different age group cut offs
- Different recommendations
Nutritional assessments definition
Used to assess nutritional status
What does the ABCD of nutritional status stand for
A = Anthropometric
B = Biochemical
C = Clinical
D = Dietary
ABCD involves understanding of
- Past (Genetic factors)
- Present (Current eating behaviours)
- Future (Capacity for growth and recovery)
Anthropometric definitions
Measurements of the human body in terms of dimensions of bone, muscle, and adipose tissue
Anthropometric measurements
- Height
- Weight
- BMI
- Weight changes
- Body composition
Biochemical definitions
Changes in biochemical markers are used to determine if nutrition interventions are effective, control of medical conditions
Biochemical measurements
- Blood and urine samples
- Blood- Plasma, cells or serum provides a lot of info
- Urine- Excretion of water-soluble nutrients
- Other- bone marrow biopsies, radiographic examination
Clinical measurements
- History provide clues about nutritional status
- Used to detect changes in external appearance of body
- Clinical examination can include; hair, face, eyes, mouth, tongue, gums, glands, skin, nails, and bone
Dietary measurements
- Energy requirements
- Eating patterns
- 24 hour recall
- Food Frequency Questionnaire (FFQ)
- Diet record/food diary
- Weighed Dietary Record
What are the 4 factors affecting nutritional status
- What we EAT
- What we ARE
- What we CAN DO
- What we PASS
What we EAT
Diet consumption including water content
What we ARE
Body composition
What we CAN DO
Functions of the body and cells
What we PASS ON
Epigenetics (genes we inherit and pass down)
What do we do with the nutritional status measurements
- Promote healthy diets
- Evidence for action
Dietary assessments
To assess and monitor food and nutrition intake
What are the limitations of dietary assessments
- Subjective
- Objective
24 hour recall
Recall a list of foods and drinks consumed over the previous 24-hour period, Including quantities, method of preparation and the time of consumption
Advantages of 24 hour recall
+ Low level of participant commitment
+ Inclusive of illiterate participants
+ Quick and Inexpensive
+ Can be repeated
Disadvantages of 24 hour recall
- Does not gain day to day variation
- Memory errors
- Quantification of portion sizes may be difficult
- Not representative of habitual diet
- Subjects talk a good diet
- Interviewer bias
Food diary
Individual weigh and record all food and drink consumed over a period
Advantages of a food diary
+ Doesn’t rely on the individual memory
+ Exact portion sizes
+ Detailed description
+ Assess actual dietary intake
+ Cross cultural comparability
Disadvantages of a food diary
- Many days of recording
- Recording may become less accurate
- Time consuming
- Individuals may alter their habitual diet
- Weighing foods eaten away from home can be hard
Food Frequency Questionnaire
A list of foods gives an indication of the typical frequency of consumption and amount consumed over a recent period
Advantages of a Food Frequency Questionnaire
+ Large scale surveys
+ Assessed habitual consumption
+ Can be designed to focus on foods of interest
+ Existing FFQs can be modified
Disadvantages of a Food Frequency Questionnaire
- Relies on memory
- Provides estimation
- Bias due to over reporting or under reporting
- Ethnic differences may not be captured
- No indication of patterns
Diet history
Assesses the subject’s usual nutrient intake including seasonal changes through questions
Disadvantages of diet history
- Lengthy interview process
- Requires highly trained interviewers
- Tend to overestimate
- Requires cooperative responders
Why do people under report in food diary
- Memory
- Mindless eating
- Social desirability bias
- Poor perception of portion sizes/measurements
- Dishonesty
Biochemical markers
These are used to estimate nutritional status and are a useful tool in investigating the amount of specific nutrients in an individual’s diet.
What are the considerations when choosing a method
- What you want to measure
- Estimated or actual food
- Period of time
- Intake of specific nutrient/food
- Frequency of composition
- Diet pattern
