Mixed
Food Frequency Questionnaires (FFQ) provide accurate estimates of mean energy intake and can reliably rank individuals by intake, but they are inaccurate for determining absolute individual energy intake levels.
If you are designing a study or analyzing population data, do not discard Food Frequency Questionnaires just because individuals might misreport their calories. The data shows that while individual reports can be off by 50%, the average is very close to reality, and the tool is excellent at ranking people from low to high intake. Use FFQs for population trends and rankings, but do not use them to prescribe precise calorie targets for a single person.
In conclusion, the FFQ appeared to be accurate for estimating the mean level of energy intakes of these participants and for ranking them according to their intake. However, the large differences found on the individual level may affect the results of epidemiological studies in an unknown direction if nutrients are corrected for energy intakes reported by FFQ.
Why this rating
High-quality controlled feeding trials with a 'gold standard' reference method (stable body weight) across 516 participants.
Source
Self-reported energy intake by FFQ compared with actual energy intake to maintain body weight in 516 adults
Els Siebelink et al. · British Journal Of Nutrition · 2011
DOI 10.1017/s0007114511000067
Related findings · Mixed
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