Clustering of (Un)Healthy Behaviours and Weight Status in New Zealand Adolescents

Abstract

PURPOSE: Forming healthy habits during adolescence is essential for setting the stage for healthy behaviours in adulthood. This study examined clustering of health behaviours (physical activity [PA] habits, screen time, fruit and vegetable intake) and weight status in New Zealand adolescents. METHODS: Adolescents from 9 secondary schools in Dunedin (New Zealand) (n=1,008; 45.6% male; age: 15.3±1.4 years) completed an online questionnaire. Participants self-reported PA, screen time outside of school, and fruit and vegetable intake. Height and weight were measured and weight status category was determined using international guidelines. Analysis included a two-step cluster analysis. RESULTS: On average, adolescents participated in ≥60 min of moderate-to-vigorous PA on 4.0±2.1 days/week, with only 16.4% meeting PA guidelines (≥60 min of moderate-to-vigorous PA every day). Adolescents reported 5.6±3.0 hours/day of screen time, with only 13.0% meeting screen time guidelines (≤2 hrs/day). More than half of students reported daily intake of fruit (56.0%) or vegetables (63.0%). However, only 28.6% of students met guidelines for both fruit and vegetable intake (more than once a day). Few students (2.6%) met all three guidelines, 10.3% met two, 29.5% met one and 57.5% did not meet any guideline. Students’ weight status was 2.9% underweight, 67.9% normal weight, 22.1% overweight and 7.1% obese. Six clusters were identified based on health behaviours, weight status (healthy/unhealthy) and gender: 1) non-compliant females with healthy weight (20.3%); 2) non-compliant males with healthy weight (18.5%); 3) non-compliant adolescents of both genders with unhealthy weight (18.8%); 4) healthy nutrition only with mostly healthy weight (17.6%); 5) meeting screen time guidelines, mostly inactive with healthy weight (12.5%); and 6) physically active, some eating healthy, and predominantly males with healthy weight (12.2%). Neither age nor socioeconomic status contributed meaningfully to cluster formation. CONCLUSION: More than half of adolescents are not meeting any of the recommended guidelines for PA, screen time and fruit and vegetable intake. Identifying clusters of adolescents based on relevant characteristics could help tailor interventions to promote healthy lifestyles in adolescents.