Changes in body mass index associated with head start participation.

OBJECTIVES The goal of this study was to determine if Head Start participation is associated with healthy changes in BMI. METHODS The sample included children participating in Head Start between 2005 and 2013 and children from 2 comparison groups drawn from a Michigan primary care health system: 5405 receiving Medicaid and 19,320 not receiving Medicaid. Change in BMI z score from the beginning to the end of each of 2 academic years and the intervening summer was compared between groups by using piecewise linear mixed models adjusted for age, gender, and race/ethnicity. RESULTS The total sample included 43,748 children providing 83,239 anthropometric measures. The Head Start sample was 64.9% white, 10.8% black, and 14.4% Hispanic; 16.8% of the children were obese and 16.6% were overweight at the initial observation. Children who entered Head Start as obese exhibited a greater decline in the BMI z score during the first academic year versus the comparison groups (β = -0.70 [SE: 0.05] vs -0.07 [0.08] in the Medicaid group [P < .001] and -0.15 [SE: 0.05] in the Not Medicaid group [P < .001]); patterns were similar for overweight children. Head Start participants were less obese, less overweight, and less underweight at follow-up than children in the comparison groups. CONCLUSIONS Preschool-aged children with an unhealthy weight status who participated in Head Start had a significantly healthier BMI by kindergarten entry age than comparison children in a primary care health system (both those receiving and those not receiving Medicaid).