The UK is thought to have one of the highest rates of childhood obesity in the developed world and approximately a third of children in Scotland are overweight or obese¹. Improving the diet of the Scottish child population is a priority for the Scottish government with national targets reflecting this². Measuring trends in consumption of particular food types offer, an opportunity to monitor over time risk behaviours which directly affects weight. As health promotion generally is more effective in affluent groups, alongside trends in eating behaviour, changes in socioeconomic inequalities must also be monitored.

Survey conducted in Scotland in 2002, 2006 and 2010

The Health Behaviour in School-aged Children study is a survey of 11, 13 and 15 year olds, carried out in schools across Scotland, selected randomly to be representative of the Scottish adolescent population in Primary 7, Secondary 2 and Secondary 4 grades respectively. The study sample included 4188, 5766 and 6414 students in each of 2002, 2006 and 2010 respectively. The participants answered questions about how many times a week they ate fruit and vegetables. The participants also answered questions relating to car ownership, computer ownership, bedroom occupancy and family holidays. These items combined make the Family Affluence Scale (FAS), a proxy measure for SES often used among adolescents3. Weekly consumption frequencies of each food type were modelled using multilevel linear modelling, adjusting for age, sex, school grade, school type and year. FAS was introduced to each of the models to measure the association with family affluence and an interaction term between FAS and year gave an indication of whether the association between FAS and consumption frequency changed over time.

Fruit and vegetables consumption increased between 2002 and 2010

Overall, the number of days on which fruit was consumed increased between 2002 and 2010, by 0.25 days per week and the number of days on which vegetables were consumed increased between 2002 and 2010 by 0.28 days per week. However, between 2006 and 2010 slight decreases in both fruit and vegetable consumption were observed. There was some modest correlation (r2=0.48) between fruit and vegetable consumption suggesting that children may cluster by ‘healthy’ eating and ‘unhealthy’ eating.

The association between age, sex and family affluence and F&V

Fruit consumption was more frequent among girls and among younger children, while vegetable consumption was more frequent among girls but was not associated with age or grade. Fruit and vegetables were consumed by children with high FAS more frequently than those with low FAS. When an interaction term was added between year and FAS this was not significant for either outcome, suggesting that while consumption frequency has increased, the relationship with family affluence has not changed for either fruit or vegetable consumption.

School effects on fruit and vegetable consumption

Both fruit and vegetable consumption varied by school. The initiation of the Curriculum for Excellence4, which includes the promotion of healthy eating, fell within the period under study, as did the Schools (Nutrition and Health Promotion) Act of 20075. This Act introduced statutory requirements for school meals for the first time in Scotland. It could be hypothesised that prior to 2007, differences between schools were likely to be greater. Accordingly, when a random school parameter was added to the year variable, the increase in fruit and vegetable consumption between 2002 and 2010 was shown to vary by school with those schools performing the worst in 2002, showing greater improvements in vegetable consumption over time. Nevertheless, variability between schools in adolescent consumption of fruit and vegetables remained significant in 2010.

There is still room for improvement in Scotland

Adolescent fruit and vegetable consumption has improved over time in Scotland, across low, medium and high affluent children, with persistent socioeconomic inequalities. Although school initiatives do appear to be working, variability at the school level remains. This suggests that school initiatives and/or food provision within schools may be key in improving the eating behaviour of adolescents.

BASED ON: Levin KA, Kirby J, Currie C, Inchley J. Trends in adolescent eating behaviour: A multilevel cross-sectional study of 11- 15 year olds in Scotland, 2002-2010.
Journal of Public Health, 34, 523-531.