Food Record at a Glance

Purpose

To obtain detailed information about all foods and beverages consumed over a period of one or more days.

Description

A food record (also called a food diary) is a self-reported account of all foods and beverages (and possibly, [glossary term:] dietary supplements) consumed by a respondent over one or more days (i.e., an [glossary term:] n-day food record). Because the instrument is open-ended, there is no limit to the number of items that can be reported. Typically, respondents are requested to record foods and beverages as they are consumed throughout the reporting day (a "real-time" accounting). Respondents also may be asked to record dietary supplements consumed on the reporting day. Multiple administrations of n-day food records are often used.

It can take at least 15 minutes to complete the food record each day.

Traditionally, respondents are given a recording form and some oral and/or written instructions to help them record relevant details for all foods and beverages consumed, such as brand name, preparation method, and where consumed. Portion size is either estimated, using food models, pictures, or other visual aids, or measured, using weight scales or volume measures. Having a trained interviewer review the completed record with the respondent has been shown to increase the quality of the report [1].

Learn about other food records using the Nutritools Tool Library developed by the UK Medical Research Council.

A new generation of records that takes advantage of recent technological advances is being developed. These include applications for smartphones and Internet users, and wearable photography devices (Learn More about Technology in Dietary Assessment).

Utility of Data

• Food record data can be used to assess total dietary intake and/or particular aspects of the diet:
  • The record yields detailed information on foods and beverages (and if included, supplements) consumed on a given day or over a period of days. The total amount of each specific food and beverage consumed is captured.
  • Similar types of food and beverage items reported, such as soups or sugar-sweetened beverages, can be grouped. Totals for each group can then be summed.
  • If data are linked to a nutrient composition database, nutrient intake from foods and beverages can be determined (Learn More about Food Composition Databases for 24-hour Dietary Recalls and Food Records). However, [glossary term:] total nutrient intake cannot be ascertained unless dietary supplement intake data also are included (Learn More about Dietary Supplements and Estimating Total Nutrient Intakes).
  • If data are linked to a database that translates foods and beverages into food group equivalents, such as the Food Patterns Equivalents Database, foods and beverages reported can be disaggregated into their component ingredients, which can then be converted to equivalent amounts of relevant guidance-based food groups (For more information, read a factsheet on FPED products and associated data files or its application to dietary analysis.). This provides information about the consumption of food groups of particular interest, such as the total amount of fruits, vegetables, or added sugars.
  • If information, including names of eating occasions, timing and locations of meals and snacks, sources of food and beverages, and other activities such as TV and computer use during meals, is collected, records can yield contextual information, such as meal and snack patterns, foods and beverages consumed at home and away from home, and activities during meals.
• Food records can be used to describe a population's intake (e.g., Great Britain’s cross-sectional National Diet and Nutrition Survey) (see Choosing an Approach for Dietary Assessment).
  • [glossary term:] Mean usual intakes can be estimated with a single administration of n-day records (e.g., one administration of a 1- or 3-day record). Collecting n-day records over multiple time periods (e.g., at least two non-consecutive administrations of a 1- or 3-day food record) allows application of statistical techniques to estimate [glossary term:] usual dietary intake distributions for a group (Learn More about Usual Dietary Intake).
• Food records can be used to examine relationships between diet and health or other variables, in which diet is the [glossary term:] independent variable (see Choosing an Approach for Dietary Assessment).
  • Sometimes, they are used as a [glossary term:] reference instrument to [glossary term:] validate or [glossary term:] calibrate estimates from other less-detailed assessment instruments, such as a food frequency questionnaire (FFQ).
  • They also are used as a [glossary term:] main dietary assessment instrument in conjunction with an FFQ for diet-health studies.
  • Food records may be used in large [glossary term:] prospective study designs, but the expense of coding may prohibit analysis of records for all participants. In this case, collecting records from all participants, but coding only a meaningful subset is an effective strategy [2]. This is called a [glossary term:] nested case-control analytical design, which can be used when the collection of [glossary term:] exposure information is difficult or expensive and the disease is relatively rare (e.g., a site-specific cancer). In this situation, the most efficient analysis would include data from incident cases and one or two matched controls rather than the full sample.
• Food records can be used to examine relationships between some factor and diet in which diet is the [glossary term:] dependent variable (see Choosing an Approach for Dietary Assessment).
• Food records are generally not recommended for evaluating changes in diet as a result of an intervention. This is because of the possibility of transient changes in behavior occurring in response to keeping records (this is called [glossary term:] reactivity) (Learn More about Reactivity). In addition, the potential for [glossary term:] differential response bias due to the possibility that the intervention group and control group may report their diets differently, especially following an intervention, should be considered. However, if your intent is to reinforce dietary change efforts by using the food record as a behavior modification tool, food records may be beneficial.

Limitations of Data

• Hand-written food records are inexpensive to collect but expensive to code.
• The requirements of completing a food record may limit participation in some groups, leading to potential selection [glossary term:] bias.
• Quality of data may decline with increased number of days reported.
• Reactivity is known to affect estimates [3].
• Because a single administration of an n-day food record is unable to account for [glossary term:] day-to-day variation, two or more non-consecutive administrations are required to estimate usual dietary intake distributions.

Salient Features Compared to Other Self-Report Methods

For an at-a-glance comparison of the major features of self-report instruments for assessing diet, including Food Records, see the Comparing Dietary Assessment Instruments table.

• Captures current short-term diet (in contrast to FFQ and screener).
• Self-administered (in contrast to interviewer-administered 24-Hour Dietary Recall [24HR]).
• Completed in real time so it relies on measurements or estimations, rather than on memory, for the amount of foods and beverages consumed (in contrast to 24HR, FFQ, and screener).
• Potentially affected by reactivity (in contrast to 24HR, FFQ, and screener).
• May reinforce dietary change efforts (in contrast to 24HR, FFQ, and screener) [4].
• In data from multiple, non-consecutive administrations of n-day food records, the major type of [glossary term:] measurement error is [glossary term:] random versus [glossary term:] systematic (in contrast to FFQ and screener), although systematic error also may be substantial (see Key Concepts about Measurement Error).