Dietary assessment

Question 1

What is the importance of national diet survey

Answer 1

important to assess dietary habits and nutritional status

Question 2

What is the difference between retrospective and prospective?

Answer 2

retrospective = food already consumed
- FFQ

prospective = while food is consumed
- Diary

Question 3

How to address under-reporting?

Answer 3

use objective assessment methods (biomarker)

- design instruments to reduce bias

Question 4

What is the accuracy of 24-hr recall?

Answer 4

70-80%

Question 5

In interviewing, what determines quality in the data?

Answer 5

the success of probing

Question 6

What is the multipass method and its purpose and steps?

Answer 6

To reduce underreporting

1. Quick list
2. Forgotten foods
3. Time and occasion
4. Detail cycle
5. Final probe

Question 7

What is FETA?

Answer 7

FFQ System used for EPIC Norfolk

- 130 items in it

Question 8

Why use biomarkers?

Answer 8

• objective
• quicker
• more details
  however
• collection of specimen done, with fewer details obtained
• requires sample analysis

Question 9

What type of biomarkers are there?

Answer 9

1. Recovery - allows determination of intake
2. Predictive
   - reference measurement
3. Concentration - biomarker allows ranking of intake

Question 10

Give some actual example of biomarkers for dietary assessment and its use:

Answer 10

1. Urinary nitrogen = total urine intake
2. Potassium
3. Doubly-labeled water

Question 11

What are examples of biomarkers based on properties possessed:

Answer 11

1. pH

2. Isotope ratio = d13C/d13N

Question 12

What other examples of biomarkers are based on compounds

Answer 12

1. Food components (protein, sugar, fat, micronutrients, phytochemicals)
2. Contaminants/by-products (metabolites)
   - heavy metals
   - preservatives
   - processing by-products

Question 13

Give examples of phytochemicals

Answer 13

• Alkaloids
• Alkylresorcinols
• Carotenoids
• Isothiocyanate

Question 14

What are some phenolic compounds used as biomarkers?

Answer 14

• phenolic acids

- flavonoids

Question 15

What is a respiratory chamber and its function?

Answer 15

• measure oxygen and CO2 exchange

- estimate EE based on oxygen consumption and CO2 production

Question 16

What are the assumptions of doubly-labelled water technique?

Answer 16

1. oxygen turnover in body is dominated by water flow and inspired oxygen and expired carbon dioxide
2. Hydrogen turnover in body is dominated by water flow only
3. Differences between oxygen and hydrogen turnover measure oxygen consumption

Question 17

On a timescale, which 5 dietary assessments take months to years to analyse?

Answer 17

• teeth
• bone
• nails
• hair
• RBC

Question 18

On a timescale, which 2 dietary assessments take months to analyse?

Answer 18

FFQs
Adipose tissue
(maybe hair and bones)

Question 19

On a timescale, which 3 dietary assessments take hours to analyse?

Answer 19

Urine
plasma/serum
(maybe FFQs)

Question 20

On a timescale, which 5 dietary assessments can sort-of obtain quite immediate results?

Answer 20

• 7DD (7-day diary)
• Saliva
• Sweat

Question 21

What are advanced methods of dietary assessments?

Answer 21

1. web-based questionaires

2. TADA