Lecture 8: Portion Size Estimation

Question 1

What is portion size?

Answer 1

The amount of food that is actually eaten within a defined eating episode

Question 2

What is happening to portion sizes over time?

Answer 2

They are increasing (e.g. supersized options available) - obesity epidemic

Question 3

What happens to enviornmental cues with age?

Answer 3

They come into play more e.g. 5-6 year olds will eat more when given more whereas 3-4 year olds will eat the same amount

Question 4

Does offering larger portion size effect energy intake?

Answer 4

Yes

Question 5

What are the four steps to dietary assessment?

Answer 5

1. Measure food intake
2. Convert foods to nutrients
3. Estimate absorbed intake of nutrients
4. Evaluate dietary adequacy

Question 6

What does measuring food intake require?

Answer 6

Appropriate method and tool for population, measurement aids.

Question 7

What does converting foods to nutrients require?

Answer 7

Density factors: mLs to grams

Question 8

What does evaluating dietary adequacy require?

Answer 8

Reference values for age and sex groups

Question 9

What are sources of error in dietary assessment?

Answer 9

• Memory/recall
• Incorrect use of portion size tools (interviewer)
• Quantification skills of respondent
• Density factors

Question 10

What is the 1 cup diet phenomenon?

Answer 10

Cups come in lots of different sizes: People get quite burdened with thinking about exactly how much they have had

Question 11

What are the cognitive processes of a diet recall?

Answer 11

1. Perception - amount in relation to aid
2. Conceptualisation - amount not present
3. Memory
4. Social desirability

Question 12

Who are more likely to underreport?

Answer 12

Women and overweight people

Question 13

What factors influence the accuracy of portion size estimation?

Answer 13

1. Dietary Assessment Method
2. Type of food
3. Respondent Characteristics

Question 14

What do you need to look at when recalling a recipe?

Answer 14

• Ingredients
• Quantities
• Yield before and after cooking
• % consumed

Question 15

What type of food is really easy to recall?

Answer 15

Pre-portioned food e.g. weet-bix

Question 16

What is the flat slope phenomenon?

Answer 16

That large portions are underestimated and small portions are overestimated

Question 17

What type of foods are more difficult to estimate?

Answer 17

Amorphous foods (e.g. rice, pasta, mashed potato) compared to single unit foods

Question 18

How many mLs is 1 cup?

Answer 18

250mL

Question 19

How many mLs is 1 tablespoon?

Answer 19

15mL

Question 20

How many mLs is 1 teaspoon?

Answer 20

5mL

Question 21

How is density used?

Answer 21

Measure differently shaped foods using volume and measure density: Then can convert into a gram amount

Question 22

How do ethnicity and culture influence respondent characteristics?

Answer 22

• Shared dishes
• Different utensils
• Eat hands

Question 23

How do literacy and numeracy influence respondent characteristics?

Answer 23

Self-administered versus interviewer techniques

Question 24

What are the challenges when doing recalls with children?

Answer 24

• Eat smaller amounts
• Use smaller utensils
• Varied cognitive ability
• Served by others
• More left-overs
• Food literacy

Question 24

How does age influence respondent characteristics?

Answer 24

Older adults = memory
Children = cognitive development

Question 25

What are the strengths of using automated cameras?

Answer 25

• Lower respondent burden
• Not memory reliant
• Less reliant on food literacy
• Less subjective error

Question 26

What are limitations of automated cameras?

Answer 26

• Privacy, ethical considerations
• Software dependent
• Labour intensive

Question 27

What has seen to be more accurate, computers or people?

Answer 27

Computers