10b. Food Quality and Dietary Assessment Flashcards
During which stages of food production can it be exposed to pesticides?
Growing
Harvesting
Storage
What steps can we take to reduce surface chemicals on fruit and veg?
Wash in a 2% salt solution or in a white distilled vinegar/water solutions (10%/90%)
Let sit for 15-20 mins
Why is plastic packaging harmful?
Plastics allow leaching of chemicals into foods
e.g. BPA
What is BPA and other compounds examples of?
Xenoestrogens
chemicals that mimic oestrogen in the body
How do xenoestrogens work?
They bind to oestrogen receptors, disrupting normal function
What conditions have xenoestrogens been linked to?
Hormone related diseases
Breast cancer
Prostate cancer
Fertility problems
Which plastics are most known to cause health issues?
PET PVC DEHA Polystyrene Polycarbonates
Examples of items where plastics are present
Soft drink bottles Water bottles Clingfilm Cooking oil bottles Food trays Disposable cups Metal food tin liners
Practical ways to avoid plastics
Avoid plastic wrap/clingfilm
Never heat food in plastic
Never leave food or drinks in plastic containers in the sun
Examples of plastic packaging alternatives
Greaseproof paper Wax paper Beeswax wraps Soy wax wraps Glass or stainless steel containers
What is irradiation?
Use of high energy beams, X-rays or gamma rays to prolong shelf life of food
Categories of food that can be irradiated in the EU
Fruit/veg Cereals Tubers Dried herbs Spices Fish/shellfish Poultry
How must food that’s been irradiated be declared?
On label as ‘irradiated’ or ‘treated with ionising radiation’
Show the Radura symbol
Which carcinogenic compounds can be formed during irradiation?
Radiolytic products
Which toxic chemicals can be produced during irradiation?
Benzene
Formic acid
Formaldehyde
What can survive irradiation and become mutagenic?
Bacteria
Viruses
The vitamin content of irradiated foods can be reduced by what percentage?
2-95%
Which vitamins are most affected by irradiation?
B1
C
Benefits of irradiation
Extend shelf life
Allow for long-distance shipping
What are Dietary References Values?
Set of estimates for the amount of macro/micronutrients and energy needed by different groups of healthy people, doing average activity
What are DRVs not set for?
Highly active
Unhealthy individuals
How are DRVs grouped?
Girls/boys
Females
Males
What are the age grouping for girls/boys in DRVs?
0-3 months 4-6 months 7-9 months 10-12 months 1-3 years 4-6 years 7-10 years
What are the age grouping for males/females?
11-14 years 15-18 years 19-50 years 50+ years Pregnancy/breastfeeding
What estimates are included in the DRVs?
EAR (Estimated Average Requirement)
RNI (Reference Nutrient Intake)
LRNI (Lower Recommended Nutritional Intake)
Safe intake
What is EAR (Estimated Average Requirement)?
Needed by a group
i.e. about 50% of people will need less; about 50% of people will need more
What are RNIs (Reference Nutrient Intake)?
97.5% of the population’s requirement is met
What is LRNI (Lower Recommended Nutritional Intake)?
Only 2.5% of the population’s requirement is met
i.e. most need more
What is safe intake?
Used where there is not enough evidence to set an EAR, RNI or LRNI
An amount considered to be enough for most people but below a level that could have undesirable effects
What are the limitations of DRVs?
They can give a ballpark figure of how much of a nutrient a person needs but they don’t guide that person to a nutritious food source
They are set at levels to maintain health but we aim to promote optimal health
What are the criteria for optimal nutrition?
Prevents deficiency symptoms
Optimises body stores of that nutrient
Optimises biochemical and physiological function
Minimises risk factors for chronic disease
Minimises the incidence of a disease
What are DRVs used for?
To make decisions on food policy
To inform decisions on fortification of foods
Provide nutritional education and informative labels
For health professionals to assess the nutritional adequacy of diets
For institutes/caterers to devise nutritionally adequate menus
To serve the industry - not the client!
What is food fortification?
Addition of nutrients to food and drinks
What food product has mandatory fortification?
All flour (except wholemeal, SR and wheat malt flours)
What are flours fortified with?
Calcium carbonate
Iron
Thiamine
Niacin
Which foods can’t manufacturers voluntarily fortify?
Unprocessed foods
Drinks containing more than 1.2% alcohol by volume
Why is food fortification used?
To replace nutrients lost during processing
Examples of food fortification
Flour - iron, B1, B3
Cereals - iron, B vits
Margarine - Vits A and D
What is the problem with fortification?
Uses synthetic nutrients
Portrays fortified food as healthy
Doesn’t encourage healthy eating
Many fortified foods are laden with sugar
Examples of nutritional databases providing food composition
Cronometer
My Fitness Pal
Nutritics
Nutrition Database
What are limitations of food composition tables
They don’t tell you how much of a nutrient will be absorbed
Food composition varies in nature
Food composition can be affected by growing conditions, harvesting, storage, processing and preparation
Data all stages of food from growth to cooking is unavailable
What can nutrient absorption be affected by?
Poor digestive function Malabsorption conditions Nutrient competition or enhancement Nutrient antagonists Medications
Main reasons for measuring food intake
Measure the adequacy and safety of food
Study the interrelationships between food intake and physiological factors
Assist with the diagnosis and treatment of diet related conditions
What main methods can be used to measure food intake of individuals?
Reports of foods consumed on specific days
Construction of typical food patterns
What are the different methods of reporting foods on specific days?
Menu records
Weighed records
Estimated records
24 hour recalls
Best ways to construct typical food patterns
Diet histories
Food frequency questionnaires
What are menu records?
Simplest way of recording food intake
Requires description of the food/drink consumed
Counts each meal/snack a day without quantifying the portions
When are menu records useful?
Assessing compliance with special diets
Assessing frequency of specific food use
Assessing food patterns over a longer time
Don’t have to weigh food which is problematic for some
What are weighed records?
Weighing each item of food/drink at the time it’s consumed
Usually kept for 3-7 days
Needs clear instructions on how food should be weighed
What are weighed records useful for?
Can carry out metabolic studies to determine absorption/retention of specific nutrients
To quantify the actual amounts of each macro/micro nutrient consumed and determine if intake is adequate
What are estimated food records?
Amounts of food/drink consumed are assessed by volume rather than weight
(e.g. cups, tsp, tbsp)
The descriptive amounts are converted to weights by the assessor
When are estimated food records useful?
Assessing a large number of people over a large geographic area as scales don’t need to be provided
Assessing food intake in countries/cultures that normally use spoon/cup measures
People without scales
What is 24 hr recall?
Asking individuals to recollect the types and amounts of food they have eaten
Most widely used method of obtaining information on food intake
Benefit of 24 hr recall
Doesn’t influence the type of food consumed in a way that a food record might
Limitation of 24 hr recall
Open to misinterpretation with subjects reporting a good dietary pattern in order to protect self image
Telling practitioner what they want to hear
What is a multiple pass 24 hr recall?
- Subject provides a list of foods eaten on previous day
- Practitioner obtains more detail by probing for additions like milk in tea, any alcohol, junk food etc
- Practitioner reviews the list of foods to prompt reports of other foods consumed
What does a diet history involve?
Obtaining information on the habitual food intake of a client
Open interview, followed by a crosscheck against a list of commonly consumed foods
First looks at food eaten on previous day
Then food intake for given time periods (months, years)
What is a food frequency questionnaire?
Provides a list of foods and a selection of options for how often each food is consumed
What are the limitations of food frequency questionnaires?
Only obtains information on the frequency of consumption of a food over a given time
Not on meal patterns or nutritional status
What information should food diaries contain?
All meals/snacks consumed within timeframe
Fruit/veg consumed
All fluids - water, tea, coffee, alcohol, fizzy drinks
Meds/supplements taken
Methods of preparation
Time of meals
Symptoms following meals
Triggers for eating certain foods (mood, energy)
What can an NT assess from a food diary?
Energetics of food/drinks Fruit/veg intake AOs Serving sizes Eating pattern Relationship with food Cravings Dietary type Dislikes/aversions
How can a food diary be used by an NT to inform a client on protocol?
Making sure diet is balanced
Whether foods or combination of foods cause symptoms
Making sure individual is hydrated
Frequency/time of meals may influence energy levels, unstable blood glucose, emotional eating
How junk food can impact well being
