Role of fitness in racial disparities of weight status transition among elementary and middle school youth

Introduction: Despite some stabilizing of childhood obesity rates, racial/ethnic disparities persist. Because determinants of obesity and weight transition trajectories may differ among racial/ethnic populations, race/ethnic-specific research is needed to guide prevention/intervention efforts. Methods: A longitudinal public school student health surveillance dataset (2003-2008) of 3,348 students (black=1687/white=1661) was used to assess race-specific weight and fitness trajectories among Kindergarten-8th grade students in Cambridge, MA, a diverse urban city of 108,000. Personal and environmental predictors of weight trajectories were tested using multivariable logistic regression models stratified by race. Results were shared with community groups to guide development of local interventions. Results: At baseline, white students were more likely than black students to be of healthy weight (70.7% vs. 53.5%; P<0.0001) and aerobically fit (56.8% versus 46.8%; P<0.0001). At follow-up, white students were more likely than black students to have maintained (91.7% vs. 88.8%; P<0.05) or achieved a healthy weight (38.7% vs. 30.5%; P<0.05). Likewise, white students were more likely than black students to have maintained (82.2% vs. 73.5%; P<0.0001) or achieved aerobic fitness (49.9% vs. 37.3%; P<0.0001). Achieving or maintaining aerobic fitness was the primary predictor of improved weight status at follow-up in multivariable models. This effect of fitness appeared greater among the white than black students. Community input corroborated the need for fitness promotion among black youth in Cambridge, MA. Discussion: Race/ethnic-specific analyses and community input may be useful for guiding culture-focused obesity prevention efforts. Results suggest complex relationships between fitness and weight transition among racial/ethnic populations that warrant further study.