Validity of a Self-Administered Food-Frequency Questionnaire for Assessing Amino Acid Intake in Japan: Comparison With Intake From 4-Day Weighed Dietary Records and Plasma Levels.
BACKGROUND
Interest in the physiological roles of amino acids and their impact on health outcomes is substantial and growing. This interest has prompted assessment of the habitual intake of amino acids for use in epidemiologic studies and in clarifying the association between habitual intake and plasma levels of amino acids. Here, we investigated the validity of ranking individuals according to dietary amino acid intake as estimated using a food frequency questionnaire (FFQ) in comparison with intakes from dietary records (DRs) and plasma levels.


METHODS
A total of 139 men and women selected from examinees of the cancer screening program at the Research Center for Cancer Prevention and Screening, National Cancer Center, Japan, provided 4-day weighed DRs, a semi-quantitative FFQ, and plasma samples. Plasma levels of amino acids were measured using the UF-Amino Station system.


RESULTS
Spearman rank correlation coefficients of energy-adjusted intake of amino acids from the DR and FFQ ranged from 0.40 to 0.65 for men and from 0.35 to 0.46 for women. Correlation coefficients of energy-adjusted intake from the DR and plasma levels ranged from -0.40 to 0.25 for men and from -0.16 to 0.11 for women. Similarly, no significant positive correlation coefficients were observed between intake from the FFQ and plasma levels for either men or women.


CONCLUSIONS
We confirmed that this FFQ has moderate validity in estimating amino acid intake when 4-day weighed DRs are used as a reference method, suggesting that it is suitable for ranking individuals living in urban areas in Japan by amino acid intake.
Division of Epidemiology, Research Center for Cancer Prevention and Screening, National Cancer Center.
Motoki
M
Iwasaki
Junko
J
Ishihara
Ribeka
R
Takachi
Hidemi
H
Todoriki
Hiroshi
H
Yamamoto
Hiroshi
H
Miyano
Taiki
T
Yamaji
Shoichiro
S
Tsugane
D000596:Amino Acids / Q000008:administration & dosage* / Q000097:blood; D015930:Diet Records; D004034:Diet Surveys; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results
D000596:Amino Acids