Dietitian-Led School-Based Nutrition Education and Its Effects on Knowledge, Attitudes, Behaviours and Anthropometric Measurements: A Randomised Controlled Trial

ERCT Criteria Breakdown

• Level 1 Criteria

  • C

    Class-level RCT

    • Randomisation was performed among individual students rather than by class (or school), so the class-level RCT requirement is not met.
    • "Randomisation was carried out using a random numbers table (https://www.randomizer.org) among individuals who met the inclusion criteria." (p. 3)
    • Relevant Quotes: 1) "The study population consisted of 8 classes with approximately 35 students each, for a total of 280 students." (p. 3) 2) "Randomisation was carried out using a random numbers table (https://www.randomizer.org) among individuals who met the inclusion criteria." (p. 3) 3) "Participants were assigned to the control (n=35) and intervention (n=35) groups by the researchers according to the numbers generated in the programme." (p. 3) 4) "To minimise potential contamination between groups, the intervention and control classes were located in separate classrooms, and none of the intervention materials were made accessible in shared school areas." (p. 7) Detailed Analysis: Criterion C requires random assignment at the class level (or a stronger level such as school), unless the intervention is clearly one-to-one tutoring/personal teaching. The paper explicitly states that randomisation was conducted "among individuals" and that individuals were assigned to intervention and control groups. The later discussion of keeping "intervention and control classes" in separate classrooms describes contamination control, but it does not change the stated unit of randomisation, which remains the individual student. Final summary: Criterion C is not met because the unit of randomisation is described as individual-level rather than class-level (or stronger) assignment.
  • E

    Exam-based Assessment

    • Outcomes rely on a researcher-developed Nutrition Knowledge Test and questionnaire scales rather than a widely recognised standardised exam-based assessment.
    • "Nutrition knowledge test (NKT): In order to evaluate the nutritional behaviours, knowledge level and attitudes of the students, questions prepared by making use of the literature and in parallel with the nutrition education given were used [11,12]." (p. 5)
    • Relevant Quotes: 1) "Data were collected via sociodemographic forms, anthropometric measurements, Nutrition Knowledge Test (NKT), Nutrition Attitude Scale (NAS), Nutrition Behaviour Scale (NBS), and Child Physical Activity Questionnaire (CPAQ)." (p. 1) 2) "Nutrition knowledge test (NKT): In order to evaluate the nutritional behaviours, knowledge level and attitudes of the students, questions prepared by making use of the literature and in parallel with the nutrition education given were used [11,12]." (p. 5) 3) "However, the study has some limitations. First, the NKT was developed by the researchers and has not undergone validity– reliability analyses; this may limit the psychometric sensitivity of the measurements." (p. 15) Detailed Analysis: Criterion E requires a standardised, widely recognised exam-based assessment (i.e., not a measure designed specifically for the study). The paper states the NKT uses "questions" prepared for this study and aligned with the intervention content, and it later acknowledges the NKT was developed by the researchers and lacks validity/reliability analyses. The NAS, NBS, and CPAQ are established instruments, but they are questionnaire scales rather than standardised exam-based academic assessments. Final summary: Criterion E is not met because the primary knowledge outcome is researcher-developed and the remaining measures are questionnaires rather than standardised exams.
  • T

    Term Duration

    • The between-group outcome comparison is conducted immediately after an 8-week intervention (shorter than an academic term), and the later follow-up lacks control-group measurement.
    • "The total intervention period of nutrition education for students was 8 weeks, and for parents, it was applied for a total of 4 weeks." (p. 3)
    • Relevant Quotes: 1) "The total intervention period of nutrition education for students was 8 weeks, and for parents, it was applied for a total of 4 weeks." (p. 3) 2) "The study was conducted as a pre-test (1st test before the training), nutrition education to the students and parents included in the intervention group, post-test to be applied after the training (2nd test) and follow-up test to be applied 2 months after the training (3rd test)." (p. 3) 3) "The pre-test and post-test were applied to all participants and the follow-up test was applied only to the intervention group." (p. 3) Detailed Analysis: Criterion T requires that outcomes be measured at least one full academic term after the intervention begins (typically about 3–4 months). The paper describes an 8-week intervention and a post-test conducted "after the training," making the main intervention-vs-control comparison an 8-week follow-up, which is shorter than a term. Although the study includes a later follow-up "2 months after the training," it was "applied only to the intervention group," so the trial does not provide a term-long treatment-versus-control outcome comparison. Final summary: Criterion T is not met because the primary intervention-control comparison is after 8 weeks and the longer follow-up lacks a control-group measurement.
  • D

    Documented Control Group

    • The control group’s size, baseline characteristics, and business-as-usual condition (no nutrition education/materials) are clearly described.
    • "During the study period, the control group did not receive any nutrition education, educational materials, or intervention-related content." (p. 7)
    • Relevant Quotes: 1) "The study was completed with a total of 67 participants, 32 intervention and 35 control group students, who met the inclusion criteria and participated voluntarily." (p. 3) 2) "Table 1 presents the sociodemographic characteristics. The study included 32 intervention and 35 control group students." (p. 9) 3) "During the study period, the control group did not receive any nutrition education, educational materials, or intervention-related content. Students in the control group continued their normal school curriculum without any additional contact from the research team." (p. 7) 4) "To ensure ethical fairness, the full nutrition education programme was provided to the control group after the completion of the study." (p. 7) Detailed Analysis: Criterion D requires that the control group be well documented, including who they are, baseline characteristics, and what they did (or did not) receive. The paper provides the control group sample size, reports baseline sociodemographic characteristics (Table 1), and explicitly states the control group continued normal schooling and received no intervention-related education or materials during the study. Final summary: Criterion D is met because the control group is clearly described and its business-as-usual condition is explicitly documented.

• Level 2 Criteria

  • S

    School-level RCT

    • The study is conducted within a single primary school and does not randomise at the school level.
    • "Data were collected from 4th-grade students attending a public primary school located in an urban district of Mardin, a culturally diverse city in Türkiye’s Southeastern Anatolia region." (p. 2)
    • Relevant Quotes: 1) "A randomised controlled, prospective design was conducted in a primary school in Mardin with 67 fourth-grade students (32 intervention, 35 control)." (p. 1) 2) "Data were collected from 4th-grade students attending a public primary school located in an urban district of Mardin, a culturally diverse city in Türkiye’s Southeastern Anatolia region." (p. 2) 3) "Randomisation was carried out using a random numbers table (https://www.randomizer.org) among individuals who met the inclusion criteria." (p. 3) Detailed Analysis: Criterion S requires school-level randomisation, meaning multiple schools are randomly assigned to intervention/control. The paper describes one public primary school and randomisation among individuals, not randomisation among schools. Final summary: Criterion S is not met because only one school is involved and schools were not randomised.
  • I

    Independent Conduct

    • The intervention delivery and the research activities were carried out by the study team, with no explicit independent third-party evaluation.
    • "After the pre-test was completed, the students and parents included in the intervention group were given "nutrition education" by the dieticians in the study team." (p. 6)
    • Relevant Quotes: 1) "After the pre-test was completed, the students and parents included in the intervention group were given "nutrition education" by the dieticians in the study team." (p. 6) 2) "All intervention sessions were conducted by one instructor, a Ph.D. faculty member (Assistant Professor) in Nutrition and Dietetics, with prior experience in school-based nutrition education." (p. 7) 3) "Authors' contributions Conceptualization, Ç.A., H.K., and N.A.; methodology, Ç.A., H.K., and N.A.; software, Ç.A.; formal analysis, Ç.A.; ..." (p. 17) 4) "The researcher collecting the data was blinded to group allocation throughout the study." (p. 3) Detailed Analysis: Criterion I requires independent conduct from the intervention designers/deliverers, typically shown by an external evaluator or explicit independence statements for data collection and analysis. The paper states the education was delivered by dieticians "in the study team," and that the sessions were conducted by a single instructor. The author contributions indicate the same team was responsible for key study functions including analysis. Blinding of the data collector helps reduce measurement bias, but it does not establish that study conduct and evaluation were independent of the intervention team. Final summary: Criterion I is not met because the intervention and evaluation were performed by the study team without documented independent evaluation.
  • Y

    Year Duration

    • The intervention and follow-up timeline is far shorter than an academic year; additionally, T is not met, so Y cannot be met.
    • "The total intervention period of nutrition education for students was 8 weeks..." (p. 3)
    • Relevant Quotes: 1) "The total intervention period of nutrition education for students was 8 weeks, and for parents, it was applied for a total of 4 weeks." (p. 3) 2) "follow-up test to be applied 2 months after the training (3rd test)." (p. 3) 3) "The pre-test and post-test were applied to all participants and the follow-up test was applied only to the intervention group." (p. 3) Detailed Analysis: Criterion Y requires outcome measurement at least 75% of one academic year after the intervention begins. The described intervention is 8 weeks, and the follow-up is 2 months after training, which is still substantially less than a school year. Additionally, per the ERCT dependency rule, if criterion T is not met then criterion Y cannot be met. Final summary: Criterion Y is not met because the timeline is only weeks to a few months and does not approach an academic year, and T is not met.
  • B

    Balanced Control Group

    • The intervention adds instructional time and materials, but those additional resources are the treatment itself (a nutrition education programme) being tested against business-as-usual.
    • "During the study period, the control group did not receive any nutrition education, educational materials, or intervention-related content." (p. 7)
    • Relevant Quotes: 1) "Nutrition education was given to the students for eight weeks, one lesson hour (35 min) per week in the school during school hours, and to the parents face-to-face in the school conference room for one hour per week for four weeks." (p. 6) 2) "The nutrition education tools given to children consisted of an 8-week education programme, brochure and activities such as educational games and puzzles developed to reinforce the information [11,23,24]." (p. 6) 3) "During the study period, the control group did not receive any nutrition education, educational materials, or intervention-related content. Students in the control group continued their normal school curriculum without any additional contact from the research team." (p. 7) 4) "To ensure ethical fairness, the full nutrition education programme was provided to the control group after the completion of the study." (p. 7) Detailed Analysis: Criterion B evaluates whether additional resources (time, staffing, materials) given to the intervention group are balanced by comparable resources in the control group, unless the additional resources are explicitly the treatment variable being tested. Here, additional resources are clearly present (extra lesson time, parent sessions, brochures, games, and staff-delivered education), and the control group did not receive these resources during the study. However, these additional inputs are not incidental; they define the intervention being evaluated (a dietitian-led nutrition education programme compared to business-as-usual schooling). Therefore, the resource difference is integral to the treatment definition rather than a confounding add-on that should be matched. Final summary: Criterion B is met because the added time/materials/staffing are integral to the intervention package being tested against a business-as-usual control.

• Level 3 Criteria

  • R

    Reproduced

    • No independent, peer-reviewed replication of this specific trial was identified in the paper or through targeted searches using the DOI and trial identifier.
    • Relevant Quotes: 1) (No statement describing an independent replication of this trial is provided in the paper.) Detailed Analysis: Criterion R requires independent replication by a different team in a different context, published in a peer-reviewed journal. This paper reports a single RCT in one setting and does not claim replication. Targeted internet searches (using the DOI 10.1186/s12889-026-26194-x and the trial identifier NCT07168928) did not identify any peer-reviewed replication publication by an independent author team reproducing this specific intervention and trial. Final summary: Criterion R is not met because no independent replication study of this specific trial was found.
  • A

    All-subject Exams

    • The study does not use standardised exam outcomes across core academic subjects, and E is not met, so A cannot be met.
    • "Data were collected via sociodemographic forms, anthropometric measurements, Nutrition Knowledge Test (NKT), Nutrition Attitude Scale (NAS), Nutrition Behaviour Scale (NBS), and Child Physical Activity Questionnaire (CPAQ)." (p. 1)
    • Relevant Quotes: 1) "Data were collected via sociodemographic forms, anthropometric measurements, Nutrition Knowledge Test (NKT), Nutrition Attitude Scale (NAS), Nutrition Behaviour Scale (NBS), and Child Physical Activity Questionnaire (CPAQ)." (p. 1) 2) "Nutrition knowledge test (NKT): ... questions prepared by making use of the literature and in parallel with the nutrition education given were used [11,12]." (p. 5) Detailed Analysis: Criterion A requires standardised exam-based assessment across all main school subjects, and it depends on criterion E being met. This study assesses nutrition knowledge and related attitudes and behaviours, not standardised academic exams in core subjects. Additionally, criterion E is not met due to the researcher- developed NKT. Final summary: Criterion A is not met because the study does not assess all main subjects using standardised exams, and E is not met.
  • G

    Graduation Tracking

    • The study does not track students to graduation; additionally, Y is not met, so G cannot be met.
    • "follow-up test to be applied 2 months after the training (3rd test)." (p. 3)
    • Relevant Quotes: 1) "follow-up test to be applied 2 months after the training (3rd test)." (p. 3) 2) "The pre-test and post-test were applied to all participants and the follow-up test was applied only to the intervention group." (p. 3) Detailed Analysis: Criterion G requires tracking participants until graduation from the relevant educational stage. The only follow-up described is a "2 months" post-training follow-up (and only for the intervention group), which is not graduation tracking. Targeted internet searches for follow-up publications by the same author team (Akçalı, Karadas, Ayhanci) and for publications linked to NCT07168928 did not identify any peer-reviewed follow-up study tracking this cohort to graduation. Additionally, per the ERCT dependency rule, if criterion Y is not met then criterion G cannot be met. Final summary: Criterion G is not met because the study does not track students until graduation, and Y is not met.
  • P

    Pre-Registered

    • The trial registration date reported in the paper is after the data collection period, so the protocol was not pre-registered before the study began.
    • "Trial registration: The trial is registered at ClinicalTrials.gov (CT.gov identifier: NCT07168928, Registered 11 September 2025)." (p. 1)
    • Relevant Quotes: 1) "Data were collected between November 2024 and April 2025." (p. 3) 2) "Trial registration: The trial is registered at ClinicalTrials.gov (CT.gov identifier: NCT07168928, Registered 11 September 2025)." (p. 1) 3) "The protocol of the study was registered at www.clinicaltrials.gov (NCT07168928, Registered 11 September 2025)." (p. 9) Detailed Analysis: Criterion P requires that the full study protocol be registered before data collection begins. The paper reports data collection occurred between November 2024 and April 2025, while the trial registration date reported in the paper is 11 September 2025. Because the registration date is after the data collection window, the registration is retrospective relative to study conduct and does not satisfy pre-registration. Final summary: Criterion P is not met because the study was registered after data collection had already occurred.