dietary collection methods

Question 1

define nutritional status

Answer 1

the health status of individuals or population groups as influenced by their dietary intake and utilisation of nutrients.

Question 2

What’s dietary intake ?

Answer 2

The average long term intake of particular foods or nutrients for the group or individuals under study.

Question 3

Why assess dietary intake ?

Answer 3

• Diagnosis - under or over nourished
• Monitoring - assess the effects of an intervention
• Establish prevalence - examine results between diets and disease, development of nation policies

Question 4

two types of time frames you can use for dietary collection :

Answer 4

Prospective = current, time of preparing/ cooking the meal ( ingredients )

Retrospective = looking back on eating, reflection on the previous year

Question 5

two groups of people you can use for dietary collection :

Answer 5

individual and population

Question 6

Recall bias

Answer 6

memory error where foods are forgotten/ not recorded. Recall bias can differ by food type, dietary pattern and responding characteristics such as age, sex or leevl of education.
( more likely to forget things like snacks and condiments )

Question 7

Social desirability bias

Answer 7

Individuals adjust their eating behaviours in order to be perceived more positively.

Question 8

conformity bias

Answer 8

individuals adjust their eating behaviour in order to fit in with others. This might be more common in population dietary collection or where dietary collection takes place in a group setting.

Question 9

report bias

Answer 9

may take place when participants complete dietary collection themselves - they may under or over report intakes. Underreporting is consistent and common in adults and children.

Question 10

Whats direct chemical analysis + strength and weakness

Answer 10

Each meal consumed is then duplicated and set to the lab for direct chemical analysis

• This can produce accurate results
• Very costly and not always necessary as we have lots of very good food composition tables.

Question 11

What a dietary recall + strength and weakness

Answer 11

Respondent is asked to recall/think back to the actual food and drink consumed on specific days
- Can be collected very fast and easily

• Not very accurate ( effected by age etc ), typically over 24 hour period

Question 12

whats food frequency questionair + strength and weakness

Answer 12

The respondent is presented with a list of foods and is required to say how often each is eaten ( number of times per day/ week/ month )
- Great for collecting a large amount of generic data
- Cant calculate the specific nutrient intake

Question 13

whats a diet history + strength and weakness

Answer 13

Complete an interview to establish their general diet history and dietary patterns.
- Requires trained interviewer

• Representative of diet pattern over attended periods of time

Question 14

whats a food diary / dietary record

Answer 14

Two types :
Weighed = all food is accurately weighed and recorded, alongside adequate descriptions
Estimated = descriptions of cups, teaspoons, dimensions of food portions etc

• Need a large amount of participant participation

Question 15

Whats are food diaries - remote food photography

Answer 15

Photographs are taken and then a log is taken of diet
Extremely important to take a picture of a before and after ( may not consume it all )

Question 16

note all 5/6 dietary collection methods

Answer 16

food diary + photography
diet history
dietary recall
food frequency questionnaire
direct chemical analysis