Which statement describes a limitation of a 24-hour dietary recall?

• A. It captures long-term usual intake perfectly.
• B. It relies on memory and may not reflect usual intake.
• C. It records all nutrients automatically with no error.
• D. It is unaffected by day-to-day variation.

Answer: (B)

A key idea here is that a 24-hour dietary recall depends on memory and may not represent a person’s typical eating pattern. Since what people eat varies from day to day, a single day’s recall can be atypical and fail to capture usual intake. Memory errors, omissions, and misestimated portion sizes further introduce inaccuracies, making it hard to estimate long-term nutrient intake from one day.

That’s why this option is the best description of a major limitation. In contrast, a 24-hour recall does not measure long-term usual intake perfectly, it is not automatic and error-free, and day-to-day variation does affect the results.