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
Ezendam et al., 2012 [8]	To prevent weight gain in girls by improving dietary behaviors and physical activity.	Cluster randomized controlled trial	Sample: 883 Age: 12–13 Gender: Boys and girls Country: The Netherlands	Intervention: a web-based computer programme-tailored intervention Control: No-intervention TB: Theory of Planned Behavior	Duration: 10 weeks Follow-up: baseline, after 4 months and 2 years Frequency: 8 lessons (15min each)	Higher vegetables intake and lower snack and sugar-sweetened beverages consumption in the intervention group. Higher intake of fruit was found only on adolescents with a pre low intake in the intervention group.
Haerens et al., 2007 [9]	To evaluate the acceptability, feasibility and effectiveness of a computer-tailored education program created to reduce fat intake of adolescents.	Randomized controlled trial	Sample: 333 Age: 12–14 Gender: Boys and girls Country: Belgium	Intervention: Computer-tailored dietary fat intake intervention, provided as an interactive CD-ROM. Control: No-intervention TB: Social Cognitive theory, Theory of Planned behavior, and Transtheoretical model	Duration: 50 minutes Follow-up: baseline, after 3 months Frequency: 1 session	Decreased dietary fat intake in girls enrolled in technical-vocational schools; and in boys and girls who were in general education who reported reading intervention messages. No intervention effects for total sample.
Maes et al., 2011 [10]	To investigate the feasibility and impact of an Internet-based computer-tailored nutrition intervention.	Quasi-experimental design	Sample: 1298 Age: 12–17 Gender: Boys and girls Country: Austria, Belgium, Greece, Germany, Stockholm	Intervention: computer-tailored nutrition advice for improving dietary intake of target nutrients (fiber, vitamin C, calcium, iron and fat) Control: Generic standard advice in text format covering similar topics TB: Not informed	Duration: not informed Follow-up: baseline, after 1 and 3 months Frequency: 3 sessions during school hours	No significant changes in fat intake for the intervention group
Lubans et al., 2012 [11]	To evaluate the impact of a school-based obesity prevention program for adolescents.	Cluster randomized controlled trial	Sample: 357 Age: 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	Duration: 12 months Follow-up: baseline after 12 months Frequency: weekly or bi-weekly text messages	No significant changes in BMI and body fat percentage in the intervention.
Rees et al., 2010 [12]	To evaluate the effectiveness of a computer-generated tailored intervention to increase intakes of brown bread, wholegrain cereal, fruits, and vegetables.	Cluster randomized controlled trial	Sample: 823 Age: 12–16 Gender: Girls only Country: United Kingdom	Intervention: Computer-tailored intervention, based on individual’s self-reported intake of target foods. Control: Generic leaflet based on National Guidelines (not tailored) TB: Theory of Planned Behavior, and The Transtheoretical Model	Duration: not informed Follow-up: baseline, after 3 months Frequency: 1 session	The tailored intervention leaflet had a significant effect on whole bread intake, but there were no significant effects for other foods.
Sharma et al., 2015 [13]	To evaluate the feasibility, acceptability, and effects of a computer game on dietary behaviors, physical activity behaviors, and psychosocial factors.	Quasi-experimental design	Sample: 107 Age: 9–11 Gender: Boys and girls. Country: United States of America	Intervention: a game in which players must create an avatar and make it eat healthy and stay active; and complete a series of progressive gaming challenges. Control: No-intervention TB: Social Cognitive Theory and the Theory of Reasoned Action	Duration: 6 weeks Follow-up: baseline, after 6 weeks Frequency: 90 minutes per week	The intervention group had lower sugar consumption and improved nutrition and physical activity attitudes post intervention compared to the control group.
Thompson et al., 2009 [14]	To evaluate the effects of a Boy Scout program on fruit juice and low-fat vegetable consumption.	Cluster randomized controlled trial	Sample: 473 Age: 10–14 Gender: Boys only Country: United States of America	Intervention: a website intervention to increase fruit juice and low-fat vegetable consumption with online activities (knowledge games, web recipes, goal setting, problem solving) Control: Mirror-image intervention to increase physical activity TB: Social Cognitive Theory	Duration: 9 weeks Follow-up: after 9 weeks and 6 months Frequency: 55 minutes per week	Significant increases in fruit juice consumption, fruit juice home availability, and low-fat vegetable self-efficacy in the intervention group immediately following the intervention but were not maintained 6 months later.
Whittemore et al., 2012 [15]	To compare the effectiveness of two school-based internet obesity prevention programs.	Cluster randomized controlled trial	Sample: 604 Age: 14–16 Gender: Boys and girls Country: United States of America	Intervention: Two experimental groups: - A program including lessons (nutrition, physical activity, metabolism and portion control), self-monitoring, health coaching, and social networking. - The same above plus coping skills training (addition of 4 lessons on coping skills) Control: No-intervention TB: Social Learning Theory	Duration: not informed Follow-up: after 3 and 6 months Frequency: 8 to 12 lessons	Both groups significantly improved health behaviors including self-efficacy, healthy eating, fruit and vegetable intake, moderate and vigorous exercise, and stretching exercises; decreases in consumption of sugar-sweetened beverages and junk food, and decreased sedentary behavior.
Baños et al., 2012 [16]	To investigate the efficacy for improving nutritional information and evaluate acceptability and playability of an online game.	Quasi-experimental design	Sample: 228 Age: 10–13 Gender: Boys and girls Country: Spain	Intervention: ETIOBE mates, educational website including games Control: Paper-pencil intervention TB: Not informed	Duration: 2 weeks Follow-up: baseline after 2 weeks Frequency: “as much as they wanted”	Improved nutritional knowledge for both groups. Scores were greater in the intervention group.
Bech-Larsen & Grønhøj, 2013 [17]	To increase the consumption of fruits and vegetables of Danish adolescents as well as evaluate the SMS intervention in terms of participation, goal setting, and performance of adolescents.	Cluster Randomized controlled trial	Sample: 256 Age: 12 Gender: Boys and girls Country: Denmark	Intervention: SMS-based diary and feedback system plus nutrition education Control: Nutrition education only TB: Not informed	Duration: 4 weeks Follow-up: baseline, after 15 weeks Frequency: daily SMS messages	Increased frequency of fruits and vegetables consumption only for those with a low pre-intervention intake in the intervention group.
Yang et al., 2015. [18]	To improve intake of food groups and nutritional elements using technology based team game.	Quasi-experimental design	Sample: 87 Age: 15–16 Gender: Girls only Country: Taiwan	Intervention: Two experimental groups: - Use of a Diet Assessment System for self-monitoring and metacognitive strategies; - The Diet Assessment System was also used as an online team-based competitive game Control: Traditional lecture-based instruction plus motivational elements (video clips related to healthy eating) TB: Social-interdependence theory/ social learning	Duration: 8 weeks Follow-up: baseline, after 8 weeks Frequency: 50 minutes per week	Group 2 improved dietary behaviors of most food groups (dairy, meats, proteins, vegetables and fruits), macronutrients (calories and fiber), and micronutrients (calcium, vitamin C and B2). Improvements were greater in Group 2 compared to the other two groups.

FFQ, Food Frequency Questionnaire; BMI, Body Mass Index; ICTs: information and communication technologies.