Adherence
Self-reported dietary assessment tools (24-hour recalls and Food Frequency Questionnaires) systematically underreport energy and protein intake compared to objective biomarkers (doubly labeled water and urinary nitrogen), with underreporting magnitude increasing with body mass index.
Self-reported diet logs and questionnaires are not reliable for determining exact calorie or protein intake. They consistently underestimate consumption, especially in individuals with higher BMI. For accurate tracking, objective measures or calibrated tools are required, as self-reports are subject to significant systematic error.
On average, men underreported energy intake compared with total energy expenditure by 12–14% on 24HRs and 31–36% on FFQs and underreported protein intake compared with a protein biomarker by 11–12% on 24HRs and 30–34% on FFQs. Women underreported energy intake on 24HRs by 16–20% and on FFQs by 34–38% and underreported protein intake by 11–15% on 24HRs and 27–32% on FFQs.
Why this rating
Large sample size (n=484), use of gold-standard unbiased biomarkers (DLW, urinary nitrogen), and rigorous statistical handling of measurement error.
Source
Using Intake Biomarkers to Evaluate the Extent of Dietary Misreporting in a Large Sample of Adults: The OPEN Study
Amy F. Subar · American Journal of Epidemiology · 2003
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