29
24-hour dietary recall and food record method Chap 4 of Nutritional epidemiology By WALTER WILLETT

24-hour dietary recall and food record method Chap 4 of Nutritional epidemiology By WALTER WILLETT

Embed Size (px)

Citation preview

Page 1: 24-hour dietary recall and food record method Chap 4 of Nutritional epidemiology By WALTER WILLETT

24-hour dietary recall and

food record method

Chap 4 of Nutritional epidemiology By WALTER WILLETT

Page 2: 24-hour dietary recall and food record method Chap 4 of Nutritional epidemiology By WALTER WILLETT

Introduction

24-hour dietary recall and food record method --based on foods and amounts actually consumed by an individual on one or more specific days

Food frequency questionnaires(FFQ) and diet histories—based on an individual’s perceptions of usual intake over a less precisely defined period of time

Page 3: 24-hour dietary recall and food record method Chap 4 of Nutritional epidemiology By WALTER WILLETT

Data collection methods

• 24-hour dietary recall method24-hour dietary recall method: --an in-depth interview conducted by a trained dieta

ry interviewer --Interviewees—subjects, parent,caretaker --The dietary interviewer solicits detailed informati

on about everything the subject had to eat and drink from midnight to midnight to midnight of the previous day or over the 24-hour period

--The importance of a skilled interviewer --Dependent on short term memory

Page 4: 24-hour dietary recall and food record method Chap 4 of Nutritional epidemiology By WALTER WILLETT

• Food preparation methods, recipe ingredients, brand name of commercial products, use of dietary supplements

• Interviewer(important factors in obtaining complete and accurate information): nonjudgmental manner, a neutral attitude, use open-ended questions, avoid asking questions in a manner that might influence the subject’s responses

Page 5: 24-hour dietary recall and food record method Chap 4 of Nutritional epidemiology By WALTER WILLETT

• Accurate quantification of amounts of foods—amount estimation tool –food containers, photographs, geometric shapes,number

• Using computer software—– The Minnesoda Nutrition Data System (NDS):– Currently the most commonly used method for

dietary surveys in the U.S.

• Face to face, telephone interview(saving traveling time, “surprise” effect)

Page 6: 24-hour dietary recall and food record method Chap 4 of Nutritional epidemiology By WALTER WILLETT

• Food record method --food intake is recorded by the subject(or

observer) at the time the foods are eaten-minimize reliance on memory

--Intensive training for the subjects--The fields worker weighs the raw

ingredients, as well as the individual portions of the cook dishes—determine individual food intakes

--Food quantifying tools--Carefully reviewed by a trained nutritionist

Page 7: 24-hour dietary recall and food record method Chap 4 of Nutritional epidemiology By WALTER WILLETT

Strengths and limitations of the 24-hour dietary recall and food record methods

• Strength (both methods)

- based on actual intake to estimate absolute amount rather than relative amount of nutrients.

- open ended—high level of specificity

(interviews should be sensitive to cultural difference)

• Limitation( both method)

Day to day variation

Page 8: 24-hour dietary recall and food record method Chap 4 of Nutritional epidemiology By WALTER WILLETT

Strength (recall vs. food record) - recall does not need literacy - recall is less likely to alter eating behavior - relatively minimal respondent burden

Limitation(recall vs. food record) - reliance on memory - the need for a highly trained interviewer

Limitation(food record) -High level of subject motivation

Page 9: 24-hour dietary recall and food record method Chap 4 of Nutritional epidemiology By WALTER WILLETT

Number of days and which days

• For group means---single day • For the distribution of individual intake within the

group, or relationship between individual intake and other variables—more than one day(The number of days is dependent on the studied nutrient)

• Work days vs. Weekend days combination of days of the week and not consecutive

days• Estimate of long term intake—seasonal effect• For micronutrients such as vitamin A, C—food

frequency questionnaire

Page 10: 24-hour dietary recall and food record method Chap 4 of Nutritional epidemiology By WALTER WILLETT

Reducing error in data collection

• Factors affecting data from dietary recall : Age, gender, intelligence, mood, attention, consistency of eating pattern

• Comparison of mean energy intake(Recall vs. food record) Table 4-1

Page 11: 24-hour dietary recall and food record method Chap 4 of Nutritional epidemiology By WALTER WILLETT

Reducing error in data collection• Reducing error from dietary recall: 1. Considerable training and practice of the

interviewers.2. providing a relaxed and unhurried atmosphere for

the subject.3. asking about the previous day’s activities to help

jog the subject’s memory4. providing a list of foods 5. to use an automated system for collecting the data

in which the computer provides all of the prompts for describing foods at the appropriate level of detail.

Page 12: 24-hour dietary recall and food record method Chap 4 of Nutritional epidemiology By WALTER WILLETT

-Back-

Page 13: 24-hour dietary recall and food record method Chap 4 of Nutritional epidemiology By WALTER WILLETT

• Reducing error from food record:1. Subject’s motivation2. careful training of subjects in methods of keeping

accurate records3. emphasizing the importance of the subject’s

contribution to the research4. Stressing the need for timely recording of food

intake5. Encouraging subjects to maintain usual eating habits

during the recording period(for ease of recording, social desirability).

6. Providing written examples7. to review the food records by trained nutritionist

ASAP.

Page 14: 24-hour dietary recall and food record method Chap 4 of Nutritional epidemiology By WALTER WILLETT

• Reducing error from both methods: 1. Between meals snacks2. Eating out details3. Quantification of portion sizes: Food weighing devices, photographs or food

models of more than one portion size,models of geometric shapes, training of subjects in the use of food models(Table 4-2),

4. For telephone interview, tools(ex: ruler, standard measuring cups or spoons, or a notebook of photographs of different portion sizes for selected foods) can be provided to each subjects to keep at home.

Page 15: 24-hour dietary recall and food record method Chap 4 of Nutritional epidemiology By WALTER WILLETT

• Reducing error from both methods:

5. Improvement of tools: two-dimensional visuals portraying various sizes of geometric shapes,mounds, and beverage containers to facilitate amount estimation.

6. Inducing motivation:

a. convincing participants the importance of the research and the critical role they play

b. Monetary or other types of incentives

Page 16: 24-hour dietary recall and food record method Chap 4 of Nutritional epidemiology By WALTER WILLETT

-Back-

Page 17: 24-hour dietary recall and food record method Chap 4 of Nutritional epidemiology By WALTER WILLETT

-Back-

Page 18: 24-hour dietary recall and food record method Chap 4 of Nutritional epidemiology By WALTER WILLETT

Analysis of food intake data• At individual level, by food group, by meal

pattern(the investigation of the effects of foods when eating together)

• Calculation of nutrient intakes(database of food composition)

• The degree of specificity of food description detail required at the data collection level of coding and nutrient calculation.

Page 19: 24-hour dietary recall and food record method Chap 4 of Nutritional epidemiology By WALTER WILLETT

Sources of error in nutrient calculation

• Inaccuracies in the coding of food intake data.—data entry check of the computer system, intensive training and certification of coders, 10% or 20% duplicate coding.

• Accuracy and representitive of the nutrient values in food composition databases.

• The use of outdated nutrient data

• Analytical methodology

Page 20: 24-hour dietary recall and food record method Chap 4 of Nutritional epidemiology By WALTER WILLETT

Validation of 24-hour recalls and food records

• Reporting accuracy

• Accuracy of nutrient calculations

• Accuracy of assessing usual intake

(how well the selected days of intake represent usual individual intake)

Page 21: 24-hour dietary recall and food record method Chap 4 of Nutritional epidemiology By WALTER WILLETT

• Reporting accuracy 1. omissions of food items are more common than ad

ditions. (side dishes or add-ons)(Figure4-1) 2.overestimation appears to be more frequent than un

derestimation for portion sizes (Table 4-4). (Beverages—best estimation, add-ons-poorest estimation)

3. The underreporting of energy intake observed in validation studies of records and recalls is more likely due to omissions in reporting foods than to underestimate of portion sizes.

4. The greatest difficulty in estimating amounts was associated with items that could not be separate visualized.

.

Page 22: 24-hour dietary recall and food record method Chap 4 of Nutritional epidemiology By WALTER WILLETT

• Reporting accuracy

5. Overall, recalls tend to underestimate intake by about 10% compared with observed intake(vary considerably among individuals).

6. Flat slope syndrome:

Overestimaton of portion sizes tended to be greater among those who ate smaller portions and underestimamtion by those who ate larger portions.

Page 23: 24-hour dietary recall and food record method Chap 4 of Nutritional epidemiology By WALTER WILLETT

-Back-

Page 24: 24-hour dietary recall and food record method Chap 4 of Nutritional epidemiology By WALTER WILLETT

-Back-

Page 25: 24-hour dietary recall and food record method Chap 4 of Nutritional epidemiology By WALTER WILLETT

• Accuracy of nutrient calculations

1. (Table 4-5) calculated values tend to be higher than the analyzed values.

Page 26: 24-hour dietary recall and food record method Chap 4 of Nutritional epidemiology By WALTER WILLETT

• Accuracy of assessing usual intake 1. The use of biochemical indicator(Ch9) 2. Underreporting—underestimation—

obesity,athlete,education,motivation,age (adolescent,elderly)---nutrient intakes expressed as a percentage of total energy intake have not been found to be biased,even when energy intake itself was under-reported)

3. Reproducibility—day-to-day variation, seasonal difference---reproducible at the group level, averaging of

multiple days of intake at the individual level

Page 27: 24-hour dietary recall and food record method Chap 4 of Nutritional epidemiology By WALTER WILLETT

• There are limitations and potential sources of error of dietary recalls and food records.---- be careful when using these methods to validate food-frequency questionnaires or diet histories designed for estimating long term usual dietary intake(CH 6).

Page 28: 24-hour dietary recall and food record method Chap 4 of Nutritional epidemiology By WALTER WILLETT

-Back-

Page 29: 24-hour dietary recall and food record method Chap 4 of Nutritional epidemiology By WALTER WILLETT

Summary

Foods records and 24-hour recalls

1. consist of specific foods consumed by an individual on one or more days

2. greater specificity for describing foods and food preparation methods, greater flexibility for analyzing the data

3. seldom used as the primary method for estimating usual intake in large scale epidemiologic research

4. important in describing mean values for groups and in validating food frequency questionnaires (most commonly used method)