Validation of a Thai semiquantitative food frequency questionnaire (semi-FFQ) for people at risk of metabolic syndrome oleh Nattvara Nirdnoy, Kitti Sranacharoenpong, Apinya Surawit, Bonggochpass Pinsawas, Pichanun Mongkolsucharitkul, Tanyaporn Pongkunakorn, Thamonwan Manosan, Suphawan Ophakas, Sophida Suta, Sureeporn Pumeiam, Korapat Mayurasakorn, Siriraj Health Study Group