St George SM, Van Horn ML, Lawman HG, Wilson DK. Reliability of 24-Hour Dietary Recalls as a Measure of Diet in African-American Youth. J Acad Nutr Diet 2016 Oct;116(10):1551-9. Epub 2016 Jul 6.


BACKGROUND: Although it is a common practice to estimate dietary intake using three random 24-hour dietary recalls, some studies have suggested up to nine may be necessary to reliably estimate usual intake in youth. Given the resulting increase in resources and participant burden, more research is needed to determine whether this method is reliable, particularly in African-American youth at increased risk for obesity and other chronic diseases. OBJECTIVE: This study estimated the reliability with which 24-hour dietary recalls measure energy, fat, fruit, and vegetable intake in African-American youth and examined how reliability changes as a function of the number of recalls. DESIGN: This study used cross-sectional data collection across three studies. PARTICIPANTS/SETTING: Participants were African-American youth (n=456, mean±standard deviation age 13.28±1.86 years, 64% were girls, mean±standard deviation body mass index [calculated as kg/m(2)] 31.45±7.94) who completed random 24-hour dietary recalls (67% completed three) conducted by research assistants using the Automated Self-Administered 24-Hour recall system (n=258) or registered dietitian nutritionists using the Nutrition Data System for Research (n=198). MAIN OUTCOME MEASURES/STATISTICAL ANALYSES: Estimates provided by multilevel models were used to calculate the proportion of variance accounted for between individuals and the reliability of means within individuals as a function of the number of recalls. RESULTS: Reliability estimates for assessing dietary outcomes using one to three recalls ranged from 11% to 62%. To achieve 80% reliability, the following number of recalls would need to be conducted: 8 for energy intake, 13 for fat intake, 21 to 32 for fruit intake, and 21 to 25 for vegetable intake. CONCLUSIONS: The common practice of assessing dietary intake with three recalls does so with low reliability in African-American youth. Until more objective methods for reliably estimating usual intake are developed, researchers who choose to use 24-hour dietary recalls are encouraged to include estimates of the measure's reliability in a priori power calculations for improved decision making regarding the number of observations and/or sample size.

Full Text

The full text is available at https://dx.doi.org/10.1016/j.jand.2016.05.011

At A Glance

Individual Dietary Behavior Variables

Total Energy/Energy Density
Macronutrients, including Saturated Fat


Individual Dietary Behavior

Measure Type

24-hour dietary recall

Measure Availability

Free. Access at https://epi.grants.cancer.gov/asa24/

Number of Items

Not applicable

Study location

Not Reported

South Carolina, USA



Information about Development of Measure

Twenty-four hour recalls (24HR) of food intake are typically collected by registered dietitians, or online. Regardless, low reliability of 24HRs is due to both variations in diet across days and inaccuracy in reporting. It is suggested that as many as six to nine 24HRs recalls might be needed to estimate the usual intake in youth with reasonably adequate reliability.

Study Design

Study Participants


6 - 11 Years

12 - 18 Years





Black/African American

Predominantly Low-income/Low-SES


Sample Size


Study Design

Design Type


Health Outcomes Assessed


Obesity Measures

BMI for age

BMI Measured or Self-reported

Measured height

Measured weight


Not reported

Data Reported on Race/Ethnicity

Quantitative data on study sample

Data Reported on SES

Quantitative data on study sample

SES-related Variables


How To Use


Who Administered


How Administered


Time Required

Not reported

Training Required

Not reported

Instructions on Use

Instructions on instrument use included in article

Data Analysis

Data Collection/Analysis Costs

Not reported

Data Collection/Protocol

Participants were children and adolescents who completed twenty-four hour dietary recalls (24HR) as part of their participation in one of three studies: a cross-sectional health assessment study (study one); a family based, health-promotion intervention (study two); or a family-based, weight-loss efficacy trial (study three). Three 24HRs (either Modified Automated Self-Administered 24-Hour Protocol or registered dietitian administered) were completed for each participant on randomly assigned days determined by study staff and not scheduled with participants in advance.

Instructions on Data Analysis

Instructions on analysis included in article

Validity (0)

There are no validity tests reported for this measure.

Reliability (2)

Type of reliability Construct/subscale assessed Test/statistic used Result
Internal Consistency Modified Automated Self-Administered 24-Hour Protocols for three days of intake (studies one and two) Intraclass correlation coefficients (ICC) ICC = 0.35 for total energy; ICC = 0.24 for fat intake; ICC = 0.11 for fruit intake; ICC = 0.16 for vegetable intake
Internal Consistency Registered dietitian-administered recalls for three days of intake (study three) Intraclass correlation coefficients (ICC) ICC = 0.33 for total energy; ICC = 0.23 for fat intake; ICC = 0.16 for fruit intake; ICC = 0.13 for vegetable intake