24-Hour Dietary Recall

A 24-hour dietary recall is an interview- or software-guided method in which a respondent reports, in detail, all foods and beverages consumed during the previous 24 hours or the preceding day. It captures recent intake with high specificity and is a core instrument in national nutrition surveillance and in calibrating other dietary methods.

Definition

A 24-hour dietary recall is a structured retrospective report of all foods and beverages an individual consumed during a defined recent period (typically the prior day or preceding 24 hours), collected through a guided interview or equivalent automated instrument.

Scope

This entry covers the structure of the 24-hour recall, the multiple-pass interviewing approach that improves its completeness, its automated self-administered variants, and how single versus repeated recalls relate to usual intake. It treats the recall as a measurement method, not as a clinical or dietary-counselling tool.

Core questions

• How does a guided multiple-pass interview improve recall completeness?
• How do single and repeated recalls relate to a person's usual intake?
• What do automated self-administered recalls change about feasibility and standardisation?
• Where does misreporting enter even a detailed recall?

Key concepts

• Open-ended recent-intake reporting
• Multiple-pass interviewing
• Automated self-administered recall (ASA24)
• Single versus repeated recalls
• Within-person day-to-day variation
• Misreporting of energy intake
• Portion-size estimation

Mechanisms

In a 24-hour recall the respondent reconstructs an entire day of eating, prompted in structured stages to recover forgotten items and to specify foods, preparation, and amounts. The USDA Automated Multiple-Pass Method formalises this into successive passes (a quick list, forgotten-foods probes, time and occasion, detail and amount, and a final review), which improves completeness of reported intake (Conway et al., 2003). A single recall reflects one day and is subject to large day-to-day variation, so multiple recalls per person are needed to approximate usual intake. Automated self-administered tools such as ASA24 deliver a standardised multiple-pass recall without an interviewer, broadening feasibility for large studies (Subar et al., 2012). Even detailed recalls are subject to systematic underreporting of energy, as biomarker studies have shown (Subar et al., 2003).

Clinical relevance

The 24-hour recall provides the dietary data behind major surveillance systems and serves as a reference for evaluating other instruments, so its properties matter for appraising nutrition evidence. This entry describes a measurement method and is not a basis for individual dietary assessment or advice.

Epidemiology

Repeated 24-hour recalls administered by the multiple-pass method are the dietary backbone of population surveillance programmes, where they are applied to representative samples to estimate intake distributions. Validation against recovery biomarkers indicates that recalls, while more accurate than questionnaires for absolute intake, still underestimate energy in a portion of respondents (Subar et al., 2003).

Evidence & guidelines

Methodological consensus holds that multiple non-consecutive 24-hour recalls, collected with a standardised multiple-pass protocol, are preferred for estimating usual intake distributions in populations, and that single recalls should not be read as a person's habitual diet (Conway et al., 2003; Subar et al., 2012).

History

The 24-hour recall developed as an open-ended alternative to fixed food lists, and its reliability improved markedly with the structured multiple-pass methods refined by the USDA in the early 2000s. Web-based automated recalls such as ASA24, released later that decade, standardised administration and reduced the cost of collecting detailed dietary data at scale.

Debates

How many recalls are needed to characterise usual intake?

A single recall captures only one day and is dominated by within-person variation, so methodologists debate how many repeated recalls are needed, and how to model their distribution, to estimate habitual intake for episodically consumed foods.

Key figures

• Alanna Moshfegh
• Amy Subar
• Joan Conway

Seminal works

• conway-2003
• subar-2012-asa24

Frequently asked questions

Why is one 24-hour recall not enough to describe someone's usual diet?

A single recall reflects only one day, and intake varies substantially from day to day, so multiple non-consecutive recalls are needed to approximate a person's habitual intake.

What is the multiple-pass method?

It is a structured recall procedure that guides the respondent through several passes, including a quick list, forgotten-foods probes, and detailed amounts, to improve the completeness of reported intake.