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'Boden Food Plate': Novel Interactive Web-based Method for the Assessment of Dietary Intake
Published on: September 18, 2018
Validation of Net Endogenous Acid Production from the Automated Self-Administered 24-h Recall, 4-d Food Records, and
Douglas C Chang1, Kevin W Dodd2, Matthew K Abramowitz3
1Phoenix Epidemiology and Clinical Research Branch, Division of Intramural Research, National Institute of Diabetes and Digestive and Kidney Diseases, Phoenix, AZ, United States.
Background:
Although prior evidence indicates that dietary acid load (DAL) is important for health, the ability to accurately measure habitual DAL in the community is limited.
Objectives:
The aim was to compare net endogenous acid production (NEAP, a measure of DAL) by multiple automated self-administered 24-h recalls (ASA24s), food frequency questionnaires (FFQs) and 4-d food records (4DFRs) against NEAP measured by urine to assess measurement error.
Methods:
Over 1 y, 1082 females and males (50%), aged 50-74 y, were asked to complete 6 ASA24s, 2 FFQs, and 2 4DFRs, and 2 24-h urine collections (n = 765 completed both). The geometric means of NEAP by self-report tools were compared with urine. Correlation coefficients and attenuation factors (< 0.4 undesirable; 1.0 optimal) between self-reported and the urine biomarkers were estimated.
Results:
Mean NEAP by urine was 47.3 mEq/d [interquartile range (IQR) 36.0-63.9] in females and 48.1 mEq/d (IQR 37.2-64.2) in males. Compared with urine, mean NEAP was underestimated by -26.1% to -34.4% on FFQs, whereas ASA24 and 4DFR means differed by -5.3% to +9.0%. For a single ASA24, 4DFR, and FFQ, attenuation factors were 0.22, 0.48, and 0.31, and correlation coefficients were 0.37, 0.54, and 0.42, respectively. Averaging repeated administrations of 6 ASA24s, 2 4DFRs, and 2 FFQs are expected to improve attenuation factors to 0.61, 0.65, and 0.36, and correlation coefficients to 0.62, 0.62, and 0.46, respectively. Attenuation factors after regression calibration are expected to be close to 1 for ASA24 (0.95) and 4DFR (0.99) but lower for FFQ (0.43).
Conclusions:
For estimating long-term NEAP, the ASA24 and 4DFR may be more advantageous compared with FFQ, particularly for estimating means and when replication of assessments and application of regression calibration are considered. The findings are useful for planning future studies to understand the health impact of acid stress.
Trial Registration Number:
This study was registered at clinicaltrials.gov as NCT03268577.
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