Adjusted within-student BMI change, by 2003 state law* and 2003–2006 law change.† *State middle school law in 2003. †Difference between mean rating for state elementary school laws in 2003 and middle school laws in 2006. No change–none: Equal mean rating (0). No change–weak: Equal mean rating (1–2). No change–strong: Equal mean rating (>2). New laws–weak: Mean higher for 2006 middle school laws (1–2). New laws–strong: Mean higher for 2006 middle school laws (>2). Weaker: Mean lower for 2006 middle school laws. ‡Adjusted for race/ethnicity, gender, age, locale, SES, Census region, physical activity level, and 2003 state obesity prevalence. §Estimated from fixed-effect model, adjusted for SES and locale.