What factors are associated with frequent unhealthy snack-food consumption among Australian secondary-school students?

OBJECTIVE To examine demographic and behavioural correlates of unhealthy snack-food consumption among Australian secondary-school students and the association between their perceptions of availability, convenience and intake with consumption. DESIGN Cross-sectional survey of students' eating, physical activity and sedentary behaviours using validated instruments administered via an online questionnaire. SETTING Australian secondary schools across all states/territories. SUBJECTS Secondary-school students aged 12-17 years participating in the 2009-10 National Secondary Students' Diet and Activity (NaSSDA) survey (n 12 188). RESULTS Approximately one in five students (21 %) reported consuming unhealthy snack foods ≥14 times/week ('frequent snackers'). After adjusting for all covariates, older students and those with a BMI of ≥25 kg/m² were less likely to be frequent snackers, while students who reported high fast-food and high sugar-sweetened beverage consumption and those who watched television for >2 h/d were more likely to snack frequently. Furthermore, after adjusting for all covariates and demographic factors, students who agreed that snack foods are usually available at home, convenient to buy and that they eat too many snack foods were more likely to be snacking frequently. Conversely, students who agreed that fruit is a convenient snack were less likely to be frequent snackers. CONCLUSIONS Frequent unhealthy snack-food consumption appears to cluster with other poor health behaviours. Perceptions of availability and convenience are factors most readily amenable to change, and findings suggest interventions should focus on decreasing the availability of unhealthy snack foods in the home and promoting healthier options such as fruit as convenient snacks.