Nutritional interventions for adolescents using information and communication technologies (ICTs): A systematic review

A cost-effective and interactive way of promoting healthy nutrition behaviors among adolescents is using information and communication technologies (ICTs). We systematically reviewed studies to identify technologies and their main characteristics used for nutritional interventions for adolescents, as well as to evaluate their quality and effectiveness. Our full protocol is available on the PROSPERO website (#CRD42016035882). A search was conducted across five databases for articles describing nutritional interventions that used ICTs designed mainly for healthy adolescents. Randomized controlled trials, quasi-experimental and observational studies, and full and original papers, all of them published from 2005 to 2015, were included. Study quality was assessed by the Effective Public Health Practice Project Quality Assessment Tool. Our search yielded 559 titles and abstracts. Eleven studies met the inclusion criteria. Participants were recruited mostly from schools. Study follow-up ranged from two weeks to two years. Four interventions were based on the Social Cognitive Theory. Interventional strategies included computer games, programs, text messages, and interactive CD-ROMs. Nine studies used computer-mediated ICTs. Five studies focused on multiple behaviors simultaneously. Participants were exposed to interventions only once, daily, weekly, or according to a pre-determined number of lessons. Five studies had significant outcomes. Our quality assessment revealed three studies to be weak due to non-representativeness of their samples and usage of non-validated questionnaires. Besides the heterogeneity and poor quality of the analyzed studies, it can be suggested that long-term interventions for adolescents that make use of frequent exposure to technological resources, and that have a theoretical component aimed at a single health behavior change, tend to be more successful.


Introduction
Adolescence is considered a nutritional risk period marked by deep psychological, physiological, and social changes.In this age group, nutritional literature shows a prevalence of inadequate dietetic habits, such as high intake of processed or sugary foods, long gaps between meals, and low consumption of fruits and vegetables.The long-term effects of these eating patterns can result in overweight, as well as micronutrient deficiencies and chronic diseases that if left untreated can be dragged into adulthood [1].
Nutrition interventions are a cost-effective way to promote health behaviors and reduce obesity and chronic diseases among teens [1].Use of the internet and technological resources is growing, especially among adolescents.As reported by the Pew Research Center in 2015, 92% of the American adolescents aged thirteen to seventeen indicated going online at least once a day.Furthermore, 88% and 87% mentioned having daily access to a mobile phone or to a desktop, laptop or computer, respectively [2].
A number of nutritional interventions, including some related to health promotion, have been delivered using information and communication technologies (ICTs), such as e-mails, websites, computer programs, smartphones, text messages, or games [3].The use of web-based resources in the healthcare scene has given rise to a more innovative and interactive way of promoting behavior change and ultimately improving health programs [4].Recently, Salam et al. highlighted the use of ICTs as an ideal platform for health interventions for teenagers, as it is considered to be "adolescent-friendly".This approach could be useful even for disadvantaged adolescents or for those turned off by traditional health education methods [5].
Consequently, this systematic review identified the different technologies, as well as their main characteristics, that have been used for nutritional interventions directed at adolescents.A secondary objective was to evaluate the quality and effectiveness of these studies.

Methods
Our full protocol is available on the PROSPERO Website (#CRD42016035882).The intervention followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines [6].

Data sources and search strategy
In order to find studies with valuable information about nutrition education interventions for adolescents that employed ICTs, five databases were searched: PubMed/MEDLINE, Scielo.ORG, Web of Science, PsycINFO, and Scopus.Several MeSH terms were applied to represent ICT (i.e., mobile health, cell phones, text message), nutrition (i.e., food consumption, eating patterns, dietary behavior), intervention (i.e., intervention study, training programs, health education), and adolescents (i.e., adolescence, teen, youth).Our full electronic search strategy for PubMed can be found in Fig 1 .We reviewed articles in English, Portuguese and Spanish.

Selection criteria
Only randomized controlled trials, quasi-experimental and observational studies, full papers, and original articles, all of them published between January 2005 and January 2016, were considered for this review.The MeSH terms needed to be identifiable in the title or abstract.Description of the technology and/or intervention had to be available in the full paper.Participants were required to be healthy, but not necessarily to have a normal weight.Studies that included children older than eight or young adults could still be selected as long as they focused on adolescents between the ages of ten and nineteen.

Selection process
The list of titles and abstracts were downloaded and organized via the program Mendeley.Duplicates were removed and the remaining studies were sorted for eligibility by two reviewers.The full articles selected were then retrieved.Disagreements were resolved through discussion with an expert.Hand searches from reference lists of all included articles were performed.Both reviewers and the expert are registered dietitians with a background in this research area.

Assessment on quality and risk of bias
Study quality and risk of bias were assessed by the reviewers on study design, target population, confounders, data collection methods, dropouts, intervention integrity, and final analyses using the Effective Public Health Practice Project Quality Assessment Tool (EPHPP).Based on their final score, articles were classified as weak, moderate or strong.Those considered weak were not removed, but the risk of bias of their evidence was highlighted.Again, an expert adjudicated unresolved discrepancies.

Data collection process and synthesis
Our reviewers developed a data collection form based on the guidance from the Centre for Reviews and Dissemination on undertaking reviews in healthcare [7].Independently, they extracted the data on type of publication, country, financial sources, main purpose, study design, inclusion/exclusion criteria, recruitment procedures, unit of allocation, participant characteristics (age, gender, ethnicity, social economic status or education, weight status, and comorbidities), intervention characteristics (type, frequency or duration of exposure, and theoretical basis), and outcomes (follow-up, dropout rate, type of analysis, and main and additional outcomes).Due to a lack of homogeneity within the included studies, a meta-analysis could not be performed.Data was then synthesized into a summary table.

Results
Our search yielded 559 titles and abstracts.Once they were screened, forty-four studies underwent further analyses.Eleven studies fully met the inclusion criteria, including one study that was found through hand searches of the reference lists.Fig 2 describes in detail the selection process of the included studies, and their main characteristics are listed in Table 1.Our quality assessment revealed three strong studies [8][9][10], five moderate ones [11][12][13][14][15], and three which were rated as weak [16][17][18].These latter ones had a negative EPHPP evaluation due to a nonrepresentativeness of their samples and use of non-validated questionnaires.

Theoretical basis
Four interventions used the Social Cognitive Theory as a theoretical basis, either alone [11,15] or in combination with the Theory of Reasoned Action [13] or the Theory of Planned Behavior [9].Two studies based its interventions on principles from the Social Learning Theory, which supports the role of social and affective elements in behavior change and in the adoption of healthy behaviors [15,18].

Intervention duration and frequency of exposure
Duration and frequency of exposure to intervention varied widely.In two studies participants were exposed to intervention only once [9,12], whereas other programs had daily [17] or weekly activities [11, 13-14, 16, 18].There were also studies that did not set a specific time of exposure to intervention, but rather established a number of lessons to be done within one to three months [8,10,15].Detailed information on each intervention can be found in Table 1.

Main outcomes
Five interventions had positive effects on diet that were statistically different from their baseline measurements and/or comparison group [8,[13][14][15]18].Ezendam et al. found an increased intake of vegetables and a decrease in snack and sugar-sweetened beverages four months after their intervention, but these findings had regressed after two years [8].A lower sugar consumption was also shown by Sharma et al. and Whittemore et al., whose interventions similarly resulted in a decrease in junk food intake associated with an increase in vegetable and fruit consumption [13,15].Thompson et al. found that boy scout troops underwent significant increases in fruit juice consumption and home availability immediately post-intervention, but these results were not maintained later [14].Bech-Larsen & Gronhoj also found a significant increase in fruit and vegetable consumption, but only for students who had a low baseline intake of these food groups [17].Ress et al. did not show statistically positive interventional effects in favor of fruits and vegetables, but did show an increase of brown bread servings in their experimental group [12].Yang et al., who evaluated the effects of a team-based approach to interventions, showed significant improvements in the consumption of most food groups (dairy, meats, fruits, and vegetables), as well as an increase in the consumption of fiber, calcium, and vitamins C and B2, compared to baseline measurements and to a second experimental group who underwent a more individualized intervention rather than a group interaction [18].Haerens et al. did not detect effects of their intervention in their sample as a whole, although a decrease in fat consumption was observed in girls from technical-vocational schools and in both girls and boys from general schools [9].Maes et al. reported a gradual increase of fat intake in their control group; however, fat intake in their intervention group remained stable [10].Baños et al. found a significant increase in nutritional knowledge for both their groups, although a higher score was observed across the intervention students [16].

Discussion
We systematically reviewed eleven studies, all of which used ICT-based interventions designed mainly for adolescents.This review is unique in that it presents studies that include all types of technology within the scope of the adoption of healthy eating habits, rather than focusing exclusively on weight status or obesity.Furthermore, the main objective of this review is to examine the trends in the ICTs used in interventions for teens in the last 10 years, and the description of their effectiveness is only a consequence, not our focus.This overview identifies current gaps in these trends and allows researchers to design innovative interventions so that the scientific community can better develop programs aimed at youths, allowing a wider range of technologies and their efficiency to be tested.The majority of studies recruited individuals from schools.According to Hoelsher et al., this can be helpful in providing a continuous contact with the participants, in addition to rendering the research more cost-effective.Only one of the studies whose population were minorities failed to present at least one significant outcome in their intervention groups compared to their control groups.Ricci-Cabello et al. and Nierkens et al. concluded that educational programs aimed at minorities have the potential to be more effective; however, this fact can be easily influenced by the design, duration of intervention and follow up, and sample size of the study.Further research, including more homogeneous nutritional studies, needs to be explored [1,[19][20].
Both studies which exposed participants to their interventions only once or on a daily basis presented significant immediate results.The long-term effects of the interventions, however, were not maintained.It is clear that continuous interventions are needed for outcomes to be tracked into adulthood, but the specific amount of time cannot be answered by our study.These findings are consistent with Norman et al. and Shaya et al. [21,22] The predominant theoretical basis among the studies we reviewed was the Social Cognitive Theory.Although all the studies using this theoretical framework showed immediate postintervention significant outcomes, it cannot be determined whether this phenomenon is a result of this particular theory or not.Health behavior change is complex and involves social, emotional, and cognitive determinants that ultimately influence how people adopt certain eating behaviors.These theories and models focus on understanding how these determinants influence health behaviors in order to guide future interventions.They tend to use different constructs and different theories are often used in combination.It is worth suggesting that the use of more than one health behavior theory or model can be beneficial in promoting healthy eating, because different elements are considered [21,23].
Among the intervention strategies we analyzed, only one used a CD-ROM, showing that new types of ICTs, such as games, are emerging in the healthcare scene.In this systematic review, all interventions using games have shown to be effective; this can be attributed to the entertaining way in which these interventions promote educative learning, which appeals to younger populations [16].The exclusively-smartphone-based study had positive outcomes, but our quality assessment rated is as weak, showing room for improvement in future researches.Successful interventions require identifying the types of technology most present in adolescents' routines; doing so facilitates the availability of information, as these devices are already a part of the adolescent's environment [24].
Since this systematic review found exclusively studies of high income countries, and only one of them targeted low income groups, it is hard to state conclusions about the use of ICTbased interventions in undeveloped countries.Guse et al. systematically reviewed the use of digital media to improve adolescent sexual health and found evidence to support the need of technological support and logistical help in countries with less access to technologies [25].
Most interventions reported being effective in promoting a variety of health benefits related to nutrition.Six interventions in this systematic review compared ICT-based to face-to-face programs and only a single study failed to present a superior outcome for the ICT-based intervention group.However, these studies have a short follow-up, and thus additional comparisons are necessary to prove ICT-based interventions are superior or equally effective as traditional programs for the maintenance of healthy eating behaviors in adolescents.
Regarding the advantages of ICT-based interventions, it is believed this type of delivery platform provide more personalized content and feedback for the participants in comparison to traditional approach.This feature is especially important for the promotion of healthy eating behaviors, since the participants need to incorporate the information obtained in their daily routine.Guse et al. and Lau at al found similar results in systematic reviews exploring ICT-based interventions for promoting sexual health and physical activity behavior, respectively [23,25].In addition, ICT-based interventions deliver the information in a variety of forms, such as videos and games, which seemed to be more attractive, draw attention and be easily remembered, which facilitate the communication with this age group [13,23].
A review of school-based educational programs for teens for the promotion of physical activity and health eating behaviors concluded that the use of games can increase motivation, therefore promoting the acquisition of healthy eating habits [26].Another benefit of ICTbased interventions is that they are not time-consuming.Most programs took less than an hour per week to be completed.Generic nutrition content, low motivation of participants associated with lack of time are commonly limitations of traditional intervention programs for adolescents that can be addressed with the use of technology [23,[26][27][28].However, differently from face-to-face interventions, depending on the platform adopted in a ICT-based intervention, researchers cannot truly guarantee who is actually interacting with the program (i.e. a friend can play a game displayed in a smartphone instead of the study participant), although there are a number of strategies that can be used to address this issue.Per instance, a study included in this review allowed students to play only in computers located at schools [13].
It seems that studies targeting a single behavior, such as those focused on fruit and vegetable consumption, had better outcomes after their interventions.Although this evidence is questionable due to the weak or moderate quality of some studies as well as short duration of follow-up and small sample size, it is in accordance with Norman et al. [21].Targeting healthy eating associated with physical activity seems to be have a greater impact in adolescents' health, especially on weight, since several aspects of health are being taken into consideration.Half of the studies which combined those behaviors presented positive outcomes in both variables.Despite questionable evidence due to the low number of studies, a systematic review which determined the effectiveness of interventions that focus on improving diet and physical activity behaviors in school children concluded combined interventions, mostly, present a longer lasting effectiveness of the intervention [29].
This systematic review found a number of heterogeneous studies which makes it difficult to simply synthesize our gathered data.For better scientific insights, experimental studies should be conducted with only one type of ICT component, in a strong-evidence design.Based on Whiteley et al., a greater understanding on the impact of ICTs can only be achieved once future research address randomization, representativeness of the population, and sufficient length of duration and follow-up of the intervention [30].It is also important to use standardized and validated measurement instruments to maximize comparability of results, especially in studies focusing on behavior change interventions among adolescents [5].

Conclusion
The advantages of using technology in nutritional education programs for adolescents have been evidenced.This method of delivering information has the benefit of being more interactive, and personalized, and holds greater traction among youths.As new types of ICTs are currently emerging, the results of intervention studies are basically preliminary.The heterogeneity of these studies makes it hard to state what type of intervention is more effective; however, we can suggest that long-term interventions with frequent exposure to technological resources that also have a theoretical component aimed at a single health behavior change can potentially improve nutrition behaviors.

Table 1 . Main characteristics of included studies. Study Purpose of the study Study design Participants' characteristics ICT in Intervention, control and Theoretical Basis (TB) Duration of exposure, follow-up and frequency Main results
12mple: 357Age:12-14 Gender: Girls only Country: Australia Intervention: multi-component school-based intervention program, including text messages, nutrition workshops, interactive seminars, handbooks, and sports sessions.Control: No-intervention TB: Social Cognitive Theory

Purpose of the study Study design Participants' characteristics ICT in Intervention, control and Theoretical Basis (TB) Duration of exposure, follow-up and frequency Main results
FFQ, Food Frequency Questionnaire; BMI, Body Mass Index; ICTs: information and communication technologies.https://doi.org/10.1371/journal.pone.0184509.t001