Department of Public Health, Sport and Nutrition, University of Agder, Kristiansand, Norway.
Department of Epidemiology and Biostatistics, the Amsterdam Public Health research institute, VU University Medical Center, Amsterdam, The Netherlands.
Int J Behav Nutr Phys Act. 2019 Feb 15;16(1):22. doi: 10.1186/s12966-019-0783-8.
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.
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)).
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.
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.
提倡在儿童早期增加水果和蔬菜（FV）的消费的理由是基于之前的跟踪研究结果，这些结果表明在儿童时期养成的饮食习惯会持续到成年。之前的跟踪研究有几个局限性（例如：研究样本低、重复测量次数少和/或随访时间短）。此外，据我们所知，没有研究表明儿童时期开始的饮食干预会影响饮食行为的跟踪。因此，本研究的主要目的是评估在一个大样本中，经过多次随访调查（15 年），FV 和不健康零食的跟踪情况，以及暴露于一学年的免费学校水果是否会改变跟踪情况。
这项纵向队列研究，水果和蔬菜成就标志，包括挪威的 38 所随机抽取的学校；9 所干预学校在 2001/2002 学年收到了免费水果（或蔬菜），而 29 所学校作为对照组。基线样本包括 1950 名受试者，16-92%的人参加了五次随访调查（2002-2016 年）。FV 的摄入量和不健康零食通过食物频率问卷（FFQ）进行测量。采用混合模型来估计总体跟踪系数，并评估干预是否改变了跟踪（从基线、从第一次随访（干预进行时）和从第二次随访（干预结束后））。
水果的总体跟踪系数为 0.33，蔬菜为 0.36，而不健康零食则因性别而异：男性为 0.46，女性为 0.39（交互作用 p=0.065）。大多数分析显示，干预组和对照组之间的跟踪没有显著差异。然而，从第一次随访开始，干预组和对照组之间的不健康零食的跟踪系数分别为 0.46 和 0.38（交互作用 p=0.036），从第二次随访开始，蔬菜的跟踪系数分别为 0.35 和 0.48（p=0.036）。
我们的结果表明，从儿童期到成年期，FV 和不健康零食的跟踪程度较低且适中。我们发现几乎没有证据表明免费水果干预会改变水果、蔬菜或不健康零食的跟踪情况。需要进一步研究我们是否可以影响水果、蔬菜和不健康零食的摄入跟踪，以改善公共健康。
