Table 1. Male participants in validation study.

	Mito PHC area	Kashiwazaki PHC area	Chuo-higashi PHC area	Kamigoto PHC area	Miyako PHC area	Suita PHC area	6 PHC areas
Initial registration	30	30	38	33	33	32	196
Questionnaire distributed (FFQ)
FFQ_B1 (FFQ00)1	30	30	38	32	33	32	195
FFQ_B2 (FFQ00)2	30	0	0	0	0	0	30
FFQ_R (FFQ05)3	30	30	0	31	33	32	156
FFQ_V (FFQ05)4	30	30	38	33	31	31	193
Dietary Records (DR)
DR1	30	30	37	31	33	32	193
DR2	30	30	37	31	33	30	191
DR3	30	30	36	30	33	29	188
DR4	30	30	32	29	33	29	183
28 d completed5	29	30	31	28	32	28	178
Blood provided (BL)
BL1	30	30	33	31	33	32	189
BL2	30	30	27	30	33	30	180
BL3	30	29	23	29	33	29	173
BL4	30	30	31	29	33	30	183
All seasons6	30	29	23	27	33	29	171

¹Baseline questionnaire administered at the beginning of the study. ²Second baseline questionnaire. (Only in Mito)

³5-year follow-up survey questionnaire administered at the beginning of the study (FFQ for reproducibility).

⁴Second 5-year follow-up survey questionnaire (FFQ for validity).

⁵Subjects who completed DR for all 28 days during data collection.

⁶Subjects who provided blood sample for each of the four seasons.