This document discusses various methods for assessing diet and physical activity, including their advantages and limitations. Food frequency questionnaires, 24-hour dietary recalls, and biomarkers can be used to evaluate individual food and nutrient intake, though self-reported methods are prone to error and bias. Multiple 24-hour recalls provide a better estimate of usual intake than a single recall. Physical activity can be assessed using International Physical Activity Questionnaires, though self-reported measures are not always accurate.

1. Diet and Activity Assessment
• Food frequency Questionnaires
• 24 hour food recalls
• Biomarkers
• International Physical Activity Questionnaires

2. Self-reported Methods
• Error
-Poor recall, not quantitative, or not
representative
• Bias
-social desirability bias – tend to over report
what we think we should do and underreport
what we think we shouldn’t
-especially problematic for “bad” foods

3. Assessment of individual intakes
Food frequency questionnaire (FFQ)
 Report usual frequency of consumption of each
food item from a list of food items in reference
to a specified period (past wk/mo/yr)
 Face to face interview, telephone or by self
administration
 Describes dietary patterns or food habits not
nutrient intake
 Semi quantified tools can obtain information on
portion size using household measures

4. FFQ
• Food frequency questionnaires (FFQ) are designed to assess
habitual diet by asking about the frequency with which food items
or specific food groups are consumed over a reference period (e.g.
6 months or a year)
• FFQs may be based on an extensive list of food items or a relatively
short list of specific foods.
• The foods listed should be a) major sources of a group of nutrients
of particular interest or b) foods which contribute to the variability
in intake between individuals in the population, and c) commonly
consumed in the study population.
• The length of the list of foods can range from about 20 to 200
items.
• Questionnaires can be self-administered using paper or wev-based
formats, or interviewer administered, either face-to-face or
telephone interview

5. FFQ
• Most nutrition research is interested in the usual intake
of the individual
• They can and do differ in critical areas
• The full-length Block questionnaires (e.g. Block98,
Block2005) have been shown to come quite close to
the point estimates produced by multiple days of diet
recalls and records. Very long food lists will tend to
overestimate, while short lists will tend to
underestimate.
• Are food frequency questionnaires usable for
examining an individual's diet? There is controversy
about this question.

6. NHANES FFQ
National Health and Nutrition
Examination Survey

7. • Get an accurate and complete listing of all
food/drink individual consumed within last 24
hrs
• Specifically:
– What food/drink was consumed?
– How much was consumed?
– Time it was consumed?
– How was it prepared?
– How was it served?
– Details of food (e.g low fat, 1%, whole, milk
powder, preparation, )
Assessment of individual intakes : 24 dietary recall

8. Single 24 hour recall
• This is the method of choice if the purpose of the
study is simply to describe the average intake of a
group.
• It provides a mathematically accurate group
mean.
• Does not provide a good estimate of an
individual's usual intake for any individual
member of the group.
• It can also be used to examine whether two
groups have similar mean intakes--for example,
the baseline levels of an intervention and a
control group.

9. Multiple 24 hour recalls
• If dietary intake over a number of days is
collected, the data begins to approximate an
individual's usual intake.
• Generally, at least three days of diet data are
required for the most stable nutrients, i.e.
percent of calories from fat.
• Other macronutrients require more, and
micronutrients such as vitamin C and vitamin
A require many more days.

10. Setting the stage for the Interview
• The following steps will help in eliciting truthful and complete
information:
1. Explain to participant that you need to know only what she/he
actually ate. She/he should not feel embarrassed about any food,
as there are no "good" or "bad" foods. No one eats just the right
foods all the time.
2. Do not express in words or facial expressions either approval or
disapproval of foods which homemaker mentions.
3. Do not ask leading questions that would lead homemaker to feel
she/he “should” have had a certain item and, thus, say she/he did.
http://www.csrees.usda.gov/nea/food/efnep/ers/documentation/24hour-recall.pdf

11. 24-hour Food Recall Kit
Purpose of the FOOD RECALL KIT: To assist paraprofessional/interviewer in taking the
food recall and estimating the amounts more accurately.
The Food Recall Kit should contain the following items:
• Cup - One 8-oz. plastic measuring cup
• Bowls - 2 different shapes - each holding 2 cups
• Small sauce dish - about 1/2 cup
• Plastic ruler - 6" works well and may be less cumbersome than a 12" ruler.
• Standard measuring spoons:
- 1 tablespoon
- 1 teaspoon
- 1/2 teaspoon
- 1/4 teaspoon
*Plastic Container of 2 to 3 cups rice (with tight fitting lid)
*Plastic Container of 2 to 3 cups dried beans (with tight fitting lid)
* To reduce the weight of the Food Recall Kit, dry cereal may be used instead

13. More for the kit
10 Shapes on cardboard or plastic as described in the following chart.
Identification Size To Be Measured
A 1" square Cheese, fudge
B 2" square Brownies, Cornbread
C 1/16 layer cake Cake
D 1/12 layer cake Cake
E 1/8 of a 9" pie Pie, quiche
F 1/7 of a 9" pie Pie, quiche
G 1/6 of a 9" pie Pie, quiche
H 3" square Sheet cake, Cornbread
I 4" circle Danish, pancake
J 1/4 of 12" pizza Pizza
Additional shapes of various cuts of meats
by: Ruby H. Cox, Ph.D., R.D. (1/93)

14. During the food recall
1) Start with the most recent meal or snack and
work backwards
2) First get a list of all food eaten, but not
amounts – use probing questions, i.e. “what
else did you have with this meal?”
3) Second, go back through and find out
amounts
4) If ate at a restaurant, get the name of the
restaurant

15. To get more information on the type of food
A. Encourage the participant to describe foods
as clearly as possible.
B. Describe combination dishes carefully.
Mixtures such as sandwiches, soups, stew,
pizza, casseroles, etc. can be prepared in
many ways.
C. Ask to see packages, if available, on pre-
packaged foods, and record brand name and
other pertinent information.

17. ASA 24
• https://asa24.nci.nih.gov/researcherSite/ASA2
42013.aspx

18. Biomarkers
• Objective
• Pros – less error
Not many:
- Double labeled water for total energy input
-24 hour urinary nitrogen for total protein
intake.
• Stable isotopes ratios
-13C/12C, 15N/14N, 3H/1H, 18O/16O, 34S/32S

19. International Physical Activity
Questionnaires
• The purpose of the International Physical
Activity Questionnaires (IPAQ) is to provide a
set of well-developed instruments that can be
used internationally to obtain comparable
estimates of physical activity.
• There are two versions of the
questionnaire. The short version and the long
version .
• http://www.ipaq.ki.se/downloads.htm