“…The study sites were mostly in cities, but villages were also included in the case of China (Mainland) and Japan. The protocol for collecting the food duplicate samples was previously described in detail (Watanabe et al, 1992;Shimbo et al, 1993Shimbo et al, , 1994Shimbo et al, , 1995Shimbo et al, , 1996bShimbo et al, ,c,d,e, 1997Yamada et al, 1996;Moon et al, 1997;Qu et al, 1997;Zhang et al, 1997b;Nakatsuka et al, 1998). In brief, each woman who volunteered to donate her food duplicate was instructed to cook ordinary foods (no special dishes) on the day of the survey, and requested to collect all food items (three meals of the day, snacks and drinks (alcoholic or soft, even fresh water if taken)) consumed in a given 24 h period at the same amount and in the same way (for example, with use of mayonnaise, soybean sauce, dips and topping, etc.)…”