The subjects for this analysis were had to be part of CATCH, a trial designed to evaluate the effectiveness of a multi-component school-based cardiovascular health promotion intervention, described elsewhere in detail(29-30). The main trial (1991-1994) was conducted among students in grades 3-5 attending 96 public elementary schools (56 intervention and 40 control schools) in California, Louisiana, Minnesota, and Texas. Following the main trial, two observational studies were conducted that measured physiologic and behavioral risk factors in study participants from grades 6 to 8 (1994-1997) (pre-fortification) and in grade 12 (post-fortification) (2000-2001).