24-Hour Recall
24-Hour Recall — A 24-hour recall is a structured dietary assessment interview in which a trained interviewer asks the respondent to describe in detail every food and beverage consumed in the previous 24 hours, along with portion sizes and preparation methods. The Automated Multiple-Pass Method, used in NHANES, is the standard protocol for high-quality 24-hour recalls.
What is a 24-hour recall?
A 24-hour recall is the interviewer-administered (now also self-administered, via ASA24) collection of all foods and beverages consumed in the previous 24-hour period. The respondent is guided through their day in chronological order, with detailed prompts for portion size, preparation method, brand, and additions (sauces, condiments, dressings).
The current gold standard protocol is the Automated Multiple-Pass Method (AMPM) developed by USDA and used in NHANES (the National Health and Nutrition Examination Survey). AMPM uses five sequential “passes”:
- Quick list — uninterrupted listing of all foods consumed
- Forgotten foods — prompts for commonly forgotten items (snacks, beverages, condiments)
- Time and occasion — when and where each food was consumed
- Detail cycle — portion size, preparation method, additions
- Final probe — final check for any remaining missed foods
How does a 24-hour recall work?
A skilled interviewer using AMPM typically takes 30-45 minutes per recall. Estimated portions are matched to a food database (NHANES uses USDA’s Food and Nutrient Database for Dietary Studies, FNDDS) to compute nutrient intakes.
For population-level nutrient intake estimates, two non-consecutive 24-hour recalls per person are considered minimum to characterize usual intake distribution; more recalls per person reduce within-person variance.
Why 24-hour recalls matter
24-hour recall data underpins NHANES, the principal source of US nutrition surveillance, and is the input to the bulk of published US nutrient intake statistics (“Americans consume X grams of fiber per day on average,” etc.). The ASA24 self-administered platform has democratized 24-hour recall research, allowing relatively low-cost, geographically distributed data collection.
Major limitations:
- Single day not representative of usual intake; multiple days needed
- Underreporting — adults with obesity systematically underreport energy intake by 20-40% (Hill & Davies, 2001)
- Recall error — small foods (cooking oils, condiments) often forgotten
Compared with food frequency questionnaires, 24-hour recalls capture more detail per measured day but require more administrative effort. See dietary assessment for the broader context.