Two Year Outcomes and Moderators of Intervention Effects from the NEAT Girls Obesity Prevention Group Randomised Controlled Trial (#73)
Background: Obesity prevention among youth of low socio-economic position is a public health priority given the higher prevalence of paediatric obesity in this sub-group.
Purpose: To report the two year outcomes and moderators of intervention effects from the Nutrition and Enjoyable Activity for Teen Girls (NEAT Girls) obesity prevention program.
Methods: NEAT Girls was evaluated using a group randomised controlled trial in12 secondary schools located in low-income communities in New South Wales, Australia. Participants were 357 adolescent girls (13.2 ±0.5 years) who were considered to be ‘at risk’ of obesity. The 12-month intervention was guided by Social Cognitive Theory and involved strategies to promote physical activity, reduce sedentary behaviours and improve dietary outcomes. The primary outcome was body mass index (BMI) and secondary outcomes were BMI z-score, percentage body fat (bioelectrical impedance analysis), physical activity (accelerometers), dietary intake and recreational screen-time (self-report). Potential personal, health-related and psychosocial moderators of intervention effects were examined.
Results: After 24 months, the intervention effects on BMI (adjusted mean difference [95% CI] = -0.33 [-0.97 to 0.28)], p =0.353) and BMI z-score (-0.12 [-0.27 to 0.04], p =0.178) were not statistically significant. However, there was a significant group-by-time interaction for body fat (-1.96% [-3.02 to -0.89, p =0.006). Intervention effects for physical activity, screen-time and dietary intake were not statistically significant. Moderation analysis revealed that participants who were obese at baseline and those with low physical activity self-efficacy and self-esteem were unresponsive to the intervention.
Conclusion: The NEAT Girls intervention did not impact upon the primary outcome, but changes in body fat were statistically significant and in favour of the intervention group. Moderation analyses indicated that obese adolescent girls did not benefit from the program and may require more intensive targeted approaches.
Trial Registration: Australian New Zealand Clinical Trials Registry No:ACTRN1261000033004