How to evaluate the effect of seven years of the Norwegian School Fruit Scheme (2007-2014) on fruit, vegetable and snack consumption and weight status: A natural experiment.

Aim: From August 2007 to June 2014, the Norwegian School Fruit Scheme (NSFS) legally established that all pupils in junior high and combined schools (275,000 pupils every year), but not those in primary schools (343,000 pupils every year), were entitled to a free piece of fruit or vegetable every school day. The NSFS is a natural experiment, unique in terms of scope and lengthiness. Such governmental efforts to improve the diet of the public are rarely evaluated. Thus, an evaluation of the comprehensive, well-designed NSFS is warranted. The aim was to describe how the NSFS can be evaluated using existing data sets. Methods: Four data sets have been identified for the evaluation of the NSFS: (a) the Nord-Trøndelag Health Study, (b) the Norwegian Mother and Child Cohort Study, (c) the Norwegian Child Growth Study/Growth in Teenagers and (d) Health Behaviour in School Aged Children. These comprehensive studies have collected cross-sectional or longitudinal data providing information about children's dietary consumption and/or weight status, which can be utilised in the evaluation of the NSFS. Both short- and long-term effects of the NSFS related to dietary habits and weight status and the potential effect of moderators such as socio-economic status, sex, ethnicity and the age of children and adolescents can be studied. Conclusions: Worldwide, there is a lack of well-designed, long-term studies evaluating the impact of governmental efforts to improve public diet. The present study describes how the NSFS can be evaluated using data from four large data sets on eating habits and weight status.

Tracking of fruit, vegetables and unhealthy snacks consumption from childhood to adulthood (15 year period): does exposure to a free school fruit programme modify the observed tracking?

BACKGROUND: The rationale for promoting increased consumption of fruit and vegetables (FV) at an early age is based on results from previous tracking-studies, indicating that dietary habits learned in childhood sustain into adulthood. Previous tracking studies have several limitations (e.g. low study sample, few repeated measurements and/or short a follow-up period). In addition, to our knowledge, no study has shown that a dietary intervention initiated in childhood affects tracking of dietary behaviour. The main objectives in this study were therefore to assess tracking of FV and unhealthy snacks in a large sample with multiple follow-up surveys over 15-years, and whether exposure to free school fruit for one school year modified tracking. METHOD: The longitudinal cohort-study, Fruit and Vegetables Make the Marks, included 38 randomly drawn schools in Norway; nine intervention schools received free fruit (or vegetable) in the school year 2001/2002 and 29 schools severed as control. The baseline sample included 1950 subjects, and 16-92% participated at five follow-up surveys (2002-2016). FV consumption and unhealthy snacks were measured by FFQ. Mixed models were applied to estimate overall tracking coefficients, and to assess whether the intervention modified tracking ((from baseline, from follow-up one (while intervention was running) and from follow-up two (after end of intervention)). RESULTS: Overall tracking coefficients were 0.33 for fruit, 0.36 for vegetables and differed by sex for unhealthy snacks: 0.46 males and 0.39 for females (interaction p = 0.065). Most analyses showed no significant difference in tracking between the intervention group and control group. However, from follow-up one, tracking coefficients were different for unhealthy snacks, 0.46 vs. 0.38 (interaction p = 0.036), and from follow-up two for vegetables, 0.35 vs 0.48 (p = 0.036), in the intervention group and control group, respectively. CONCLUSION: Our results indicate low to moderate tracking of FV and unhealthy snacks from childhood to adulthood. We found little evidence that the free fruit intervention modified tracking of fruit, vegetables or unhealthy snacks. More research is needed on if or how we can influence the tracking of fruit, vegetables and unhealthy snacks consumption to improve public health.

Time trends (1995-2008) in dietary habits among adolescents in relation to the Norwegian school fruit scheme: the HUNT study.

INTRODUCTION: The importance of healthy eating in adolescence is well established. The present study examined possible effects of the free Norwegian School Fruit Scheme (NSFS), changes in dietary habits between 1995 and 2008, and whether secular changes in dietary habits differed among schools who implemented the NSFS during September 2007. METHOD: We used data from the Young-HUNT1 survey conducted from 1995 to 1997 and the Young-HUNT3 survey conducted from 2006 to 2008, which are part of the Nord-Trøndelag Health Study (HUNT), a longitudinal population health study. To evaluate the NSFS, the date Young-HUNT3 participants answered the questionnaire was used to identify affiliation to the intervention group (post-September 2007, n = 1892) or control group (pre-September 2007, n = 2855). To explore dietary habits over time, adolescents attending the same schools in Young-HUNT1 (n = 4137) and Young-HUNT3 (n = 4113) were included. Further, we investigated secular changes in dietary habits according to school type (intervention schools vs control schools). In all analysis, we explored possible differential effects according to socioeconomic status (SES) and gender. A questionnaire measured adolescents' consumption of fruit, vegetables, candy, potato chips, sugar-sweetened beverages (SSB) and artificially sweetened beverages (ASB). Educational intention was used as a proxy for SES. Multilevel logistic regression was used. RESULTS: Within Young-HUNT3, the intervention group showed increased odds of daily consumption of fruit (aOR 1.7, 95% CI = 1.3-2.4) compared to the control group. Over time, adolescents were more likely to consume fruit (aOR = 1.48, 95% CI = 1.28-1.71), vegetables (OR = 1.41, 95% CI = 1.28-1.53), potato chips (aOR = 1.60, 95% CI = 1.26-2.04) and SSB (OR = 2.02, 95% CI = 1.66-2.45). Secular changes for fruit differed by school type: adolescents in intervention schools had higher odds of daily consumption (aOR = 1.82, 95% CI = 1.38-2.38) than those in control schools (aOR 1.26, 95% CI = 1.07-1.47). CONCLUSION: The results indicated that the NSFS increased adolescents' fruit consumption. In the period assessed, the study identified positive and negative changes in adolescents' dietary habits.

Effects of 1 y of free school fruit on intake of fruits, vegetables, and unhealthy snacks: 14 y later.

Background: There are not many studies evaluating the long-term effects of fruit and vegetable interventions. Objective: We examined the effects of 1 y of free fruit in elementary school on long-term consumption of fruit, vegetables, and unhealthy snacks, according to sex and educational attainment, 14 y after the intervention period. Design: In 2001, the baseline survey of the longitudinal cohort, Fruits and Vegetables Make the Marks (FVMM), included 1950 children (mean age: 11.8 y) attending 38 randomly drawn elementary schools from 2 counties in Norway. In the following 10 mo, 9 schools served as intervention schools by participating in the Norwegian School Fruit Program for free, whereas 29 schools served as control schools. A follow-up survey conducted in 2016 included 982 participants (50%) from the original study sample (mean age: 26.5 y). The consumption of fruit and vegetables was measured by a 24-h recall (portions per day), and the consumption of unhealthy snacks was measured by food-frequency questions (portions per week). Linear mixed models were performed to test possible intervention effects on the consumption of fruit, vegetables, and unhealthy snacks 14 y after the intervention period. Results: No overall intervention effects after 14 y due to the free-fruit scheme on the consumption of fruit, vegetables, and unhealthy snacks were observed, but significant interactions showed a sustained higher frequency of fruit consumption among females in the intervention group compared with the control group [mean difference (MD): 0.38 portions/d; P = 0.023] and that this effect was only significant among less-educated females (MD: 0.73 portions/d; P = 0.043). No significant long-term intervention effects were observed in the consumption of fruit among highly educated females and males nor in the consumption of vegetables or unhealthy snacks. Conclusion: Results from the present study indicate that receiving free fruit at school for 1 y may have positive long-term effects for females without higher education.