Nahomi Imaeda1,2, Chiho Goto3,4, Tae Sasakabe5,6, Haruo Mikami7, Isao Oze8, Akihiro Hosono3, Mariko Naito6,9, Naoko Miyagawa10,11, Etsuko Ozaki12, Hiroaki Ikezaki13,14, Hinako Nanri15, Noriko T Nakahata16, Sakurako K Kamano17, Kiyonori Kuriki18, Yuri T Yaguchi19, Takamasa Kayama19, Ayako Kurihara20, Sei Harada20, Kenji Wakai6. 1. Department of Nutrition, Faculty of Wellness, Shigakkan University, Obu, Aichi, Japan. imaeda@sgk.ac.jp. 2. Department of Public Health, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, Japan. imaeda@sgk.ac.jp. 3. Department of Public Health, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, Japan. 4. Department of Health and Nutrition, School of Health and Human Life, Nagoya Bunri University, Nagoya, Aichi, Japan. 5. Department of Public Health, Aichi Medical University, Nagakute, Aichi, Japan. 6. Department of Preventive Medicine, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan. 7. Cancer Prevention Center, Chiba Cancer Center Research Institute, Chiba, Chiba, Japan. 8. Division of Epidemiology and Prevention, Aichi Cancer Center Research Institute, Nagoya, Aichi, Japan. 9. Department of Oral Epidemiology, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Hiroshima, Japan. 10. Department of Public Health, Shiga University of Medical Science, Otsu, Shiga, Japan. 11. International Center for Nutrition and Information, National Institutes of Biomedical Innovation, Health and Nutrition, Shinjuku, Tokyo, Japan. 12. Department of Epidemiology for Community Health and Medicine, Kyoto Prefectural University of Medicine, Kyoto, Kyoto, Japan. 13. Department of General Internal Medicine, Kyushu University Hospital, Fukuoka, Fukuoka, Japan. 14. Department of Comprehensive General Internal Medicine, Kyushu University Faculty of Medical Sciences, Fukuoka, Fukuoka, Japan. 15. Section of Behavioral Physiology, Department of Physical Activity Research, National Institutes of Health and Nutrition, National Institutes of Biomedical Innovation, Health and Nutrition, Shinjuku, Tokyo, Japan. 16. Department of Health and Nutrition, Faculty of Nursing and Nutrition, University of Shimane, Hamada, Shimane, Japan. 17. Department of Preventive Medicine, Tokushima University Graduate School of Biomedical Sciences, Tokushima, Tokushima, Japan. 18. Laboratory of Public Health, Graduate School of Nutritional and Environmental Sciences, Shizuoka University, Shizuoka, Shizuoka, Japan. 19. Department of Advanced Cancer Science, Faculty of Medicine, Yamagata University, Yamagata, Yamagata, Japan. 20. Department of Preventive Medicine and Public Health, Keio University School of Medicine, Shinjuku, Tokyo, Japan.
Abstract
PURPOSE: The purpose of this study was to evaluate the reproducibility and validity of a short food frequency questionnaire (FFQ) for food group intake in Japan, the reproducibility and partial validity of which were previously confirmed for nutrients. METHODS: A total of 288 middle-aged healthy volunteers from 11 different areas of Japan provided nonconsecutive 3-day weighed dietary records (DRs) at 3-month intervals over four seasons. We evaluated reproducibility based on the first (FFQ1) and second (FFQ2) questionnaires and their validity against the DRs by comparing the intake of 20 food groups. Spearman's rank correlation coefficients (SRs) were calculated between energy-adjusted intake from the FFQs and that from the DRs. RESULTS: The intake of 20 food groups estimated from the two FFQs was mostly equivalent. The median energy-adjusted SRs between the FFQ1 and FFQ2 were 0.61 (range 0.38-0.86) for men and 0.66 (0.45-0.84) for women. For validity, the median de-attenuated SRs between DRs and the FFQ1 were 0.51 (0.17-0.76) for men and 0.47 (0.23-0.77) for women. Compared with the DRs, the proportion of cross-classification into exact plus adjacent quintiles with the FFQ1 ranged from 58 to 86% in men and from 57 to 86% in women. According to the robust Z scores and the Bland-Altman plot graphs, the underestimation errors in the FFQ1 tended to be greater in individuals with high mean levels of consumption for meat for men and for other vegetables for both men and women. CONCLUSION: The FFQ demonstrated high reproducibility and reasonable validity for food group intake. This questionnaire is short and remains appropriate for identifying associations between diet and health/disease among adults in Japan.
PURPOSE: The purpose of this study was to evaluate the reproducibility and validity of a short food frequency questionnaire (FFQ) for food group intake in Japan, the reproducibility and partial validity of which were previously confirmed for nutrients. METHODS: A total of 288 middle-aged healthy volunteers from 11 different areas of Japan provided nonconsecutive 3-day weighed dietary records (DRs) at 3-month intervals over four seasons. We evaluated reproducibility based on the first (FFQ1) and second (FFQ2) questionnaires and their validity against the DRs by comparing the intake of 20 food groups. Spearman's rank correlation coefficients (SRs) were calculated between energy-adjusted intake from the FFQs and that from the DRs. RESULTS: The intake of 20 food groups estimated from the two FFQs was mostly equivalent. The median energy-adjusted SRs between the FFQ1 and FFQ2 were 0.61 (range 0.38-0.86) for men and 0.66 (0.45-0.84) for women. For validity, the median de-attenuated SRs between DRs and the FFQ1 were 0.51 (0.17-0.76) for men and 0.47 (0.23-0.77) for women. Compared with the DRs, the proportion of cross-classification into exact plus adjacent quintiles with the FFQ1 ranged from 58 to 86% in men and from 57 to 86% in women. According to the robust Z scores and the Bland-Altman plot graphs, the underestimation errors in the FFQ1 tended to be greater in individuals with high mean levels of consumption for meat for men and for other vegetables for both men and women. CONCLUSION: The FFQ demonstrated high reproducibility and reasonable validity for food group intake. This questionnaire is short and remains appropriate for identifying associations between diet and health/disease among adults in Japan.