The subjects provided 7-day dietary records (DR) in 4 seasons (a total of 28 days): spring (May), summer (August), autumn (November) and winter (February). In Mito the PHC area, the study was launched in the spring of 1996, Half of the subjects from Chuo-higashi (n=32) joined the study in the summer of 1996, and the other half (n=44) in the winter of 1997. In other areas, the study began in winter of 1997.
Weighed DRs were collected over 7 consecutive days in each of the 4 seasons. Dietitians from the PHC, the cities or towns in each area instructed the subjects to weigh all foods and beverages using the measuring spoons, cups and an electronic scale provided, and to record them in a booklet especially designed for the purpose. The subjects gave detailed descriptions of each food, the method of preparation and names of the recipes. The dietitians checked the records at subjects' homes at least once during the survey.
At the end of each season, the dietitians from the PHC reviewed the records in a standardized way, and coded all the foods recorded according to the Standardized Tables of Food Composition, 4th edition,5 If codes were not available for certain local foods, the dietitians substituted the food considered to be most similar by asking subjects for details on the food. When ingredients were not obtained for any already prepared recipes, the standard recipes developed by the authors were used.
Nutrient and food calculation was done by the method used in the Cohort I validation study.6 (link) The mean daily intake of energy and 16 nutrients was calculated from the records using the Standardized Tables of Food Composition, 4th edition.5 For cholesterol, and additional nutrients and compounds such as fatty acids (saturated, monounsaturated, n-3 polyunsaturated, n-6 polyunsaturated)7 (link), dietary fiber (water-soluble, -insoluble),8 (link) selenium9 (link) and carotenoids (alpha-carotene, beta-carotene, lycopene),10 (link) the original food composition tables were developed by filling in the missing values for the Japanese composition tables. For isoflavones (daidzein and genistein), the values in the specially developed food composition table for isoflavones in Japanese foods were used.11 (link),12 (link)Additional information about the diet, the standard portions/units for rice and green tea, and brand names for usually used cooking oil, sugar, soy sauce and miso (fermented soybeans) were reported. The frequency of eating out and dietary supplement use for the week was also recorded. Name, age, sex and occupation of all members in the family, self-reported physical activity level, and the number of steps counted by pedometer for one arbitrary day in each season were reported for information on demographic status and physical activity.
Weighed DRs were collected over 7 consecutive days in each of the 4 seasons. Dietitians from the PHC, the cities or towns in each area instructed the subjects to weigh all foods and beverages using the measuring spoons, cups and an electronic scale provided, and to record them in a booklet especially designed for the purpose. The subjects gave detailed descriptions of each food, the method of preparation and names of the recipes. The dietitians checked the records at subjects' homes at least once during the survey.
At the end of each season, the dietitians from the PHC reviewed the records in a standardized way, and coded all the foods recorded according to the Standardized Tables of Food Composition, 4th edition,5 If codes were not available for certain local foods, the dietitians substituted the food considered to be most similar by asking subjects for details on the food. When ingredients were not obtained for any already prepared recipes, the standard recipes developed by the authors were used.
Nutrient and food calculation was done by the method used in the Cohort I validation study.6 (link) The mean daily intake of energy and 16 nutrients was calculated from the records using the Standardized Tables of Food Composition, 4th edition.5 For cholesterol, and additional nutrients and compounds such as fatty acids (saturated, monounsaturated, n-3 polyunsaturated, n-6 polyunsaturated)7 (link), dietary fiber (water-soluble, -insoluble),8 (link) selenium9 (link) and carotenoids (alpha-carotene, beta-carotene, lycopene),10 (link) the original food composition tables were developed by filling in the missing values for the Japanese composition tables. For isoflavones (daidzein and genistein), the values in the specially developed food composition table for isoflavones in Japanese foods were used.11 (link),12 (link)Additional information about the diet, the standard portions/units for rice and green tea, and brand names for usually used cooking oil, sugar, soy sauce and miso (fermented soybeans) were reported. The frequency of eating out and dietary supplement use for the week was also recorded. Name, age, sex and occupation of all members in the family, self-reported physical activity level, and the number of steps counted by pedometer for one arbitrary day in each season were reported for information on demographic status and physical activity.
Full text: Click here