The Nutrition and Enjoyable Activity for Teen Girls (NEAT girls) randomized controlled trial for adolescent girls from disadvantaged secondary schools: rationale, study protocol, and baseline results

Group randomized controlled trial; 12 government secondary schools in the Hunter Region and Central Coast areas of NSW, Australia; participants were Grade 8 adolescent girls disengaged from PE or not participating in organized team or individual sports; baseline data indicated overweight/obesity prevalence (26.1% overweight, 16.8% obese), mean BMI approximately 22.6 kg/m2, and mean age about 13.2 years; schools were paired (6 pairs) by location, size and demographics and randomized to NEAT Girls or wait-list control; assessments at baseline and at 12 and 24 months include adiposity, objectively measured physical activity, muscular fitness, sedentary behaviors, dietary intake, and social-cognitive mediators; analyses will follow intention-to-treat principles.

Baseline analyses show no significant differences between NEAT Girls and control groups for demographics or outcomes. Among 357 participants from 12 schools, overweight or obesity prevalence was 43% (26.1% overweight, 16.8% obese). Mean BMI ~22.6 kg/m2; average MVPA ~34 minutes/day and ~262 minutes/day of sedentary time; only about 10% met MVPA guidelines and ~11% met sedentary guidelines. NEAT Girls comprises enhanced school sport sessions, interactive seminars, nutrition workshops, lunch-time physical activity, pedometers and text messaging to promote physical activity and healthy eating. No intervention results are available yet; the trial will assess BMI (primary) and multiple secondary outcomes at 12 and 24 months; findings will inform targeted obesity prevention for low-SES adolescent girls.

Accelerometer data incomplete due to device malfunctions, with unusable data for about 50 participants; some participants wore accelerometers for fewer than the recommended four days; dietary and sedentary-behavior measures rely on self-report and may be biased; baseline sample drawn from 12 NSW schools in disadvantaged areas may limit generalizability; as this is baseline data, results do not reflect intervention effects and follow-up attrition could affect later analyses.