Two farming populations participated in the present nutritional survey
. One group consisted of rice producing farmers in Miyagi prefecture i
n north-eastern Japan, and the other group was farmers in Okinawa pref
ecture in southern Japan where agricultural activity focuses on sugar
cane and horticulture. The collection of 24-hr total food duplicates w
as carried out in winter seasons, and was repeated twice with the firs
t study in 1977-1981, and the second one in 1991-1992. In total, 154 a
nd 128 food duplicates were collected for nutritional comparisons betw
een the two prefectures at two different times. There was a significan
t reduction in intake of carbohydrate especially rice in Miyagi during
this 10 year period. In Okinawa in contrast, the reduction in intake
of carbohydrate and rice was positive but less remarkable. Thus, the r
ice consumption in 1990 was almost comparable between the rice produci
ng prefecture and the prefecture that imports rice from other prefectu
res. Such reduction was associated with the relative decrease of cerea
ls as the major protein source in Japanese daily food.