This is an excellent and crucial step for your systematic review! A well-designed data extraction form is the backbone of a high-quality review. It ensures consistency, reduces bias, and makes your data analysis much smoother.

Below is a comprehensive template for your data extraction form on nutrition interventions, categorized for clarity. Remember, this is a starting point; you'll need to pilot test it with a few studies and adjust it based on your specific research questions and the nuances of the literature you find.

Data Extraction Form Template: Nutrition Interventions Systematic Review

Review Title: [Your Systematic Review Title]
Date Extracted: [DD/MM/YYYY]
Extractor ID: [e.g., EX01]
Date Verified: [DD/MM/YYYY]
Verifier ID: [e.g., VR02]

Part A: General Study Information & Identification

• Internal Study ID: [e.g., 001] (Assign a unique ID for your review)


• Citation:


• First Author:


• Year of Publication:


• Journal/Source:


• DOI/PMID:


• Full Reference: (e.g., APA, Vancouver)


• Study Title:


• Type of Publication: (e.g., Full Journal Article, Conference Abstract, Dissertation, Pre-print)


• Language of Publication:


• Country where study was conducted:


• Trial Registration Number (if applicable): [e.g., ClinicalTrials.gov ID]


• Link to Study: (if online access is consistent)

Part B: Study Design & Methodology

• Study Design:


• [] Randomized Controlled Trial (RCT)


• [] Quasi-Randomized Controlled Trial


• [] Cluster RCT


• [] Non-Randomized Controlled Trial (NRCT)


• [] Controlled Before-After Study (CBA)


• [] Interrupted Time Series (ITS)


• [] Observational Study (e.g., Cohort, Case-Control, Cross-sectional) - If your review includes these


• [] Other (Specify):


• Study Setting: (e.g., Community, Primary Care, Hospital, School, Online, Workplace)


• Study Duration (Total): (e.g., 12 weeks, 6 months, 2 years)


• Ethics Approval Stated? [] Yes [] No [] Not Reported


• Randomization Method (if applicable):


• Method Used: (e.g., computer-generated sequence, coin toss, random number table, minimization, block randomization, stratified randomization)


• Adequacy of Sequence Generation: [] Adequate [] Inadequate [] Unclear [] Not applicable


• Concealment of Allocation: (How was allocation sequence protected?)


• [] Adequate (e.g., opaque sealed envelopes, central randomization)


• [] Inadequate (e.g., open list, known sequence)


• [] Unclear


• [] Not applicable


• Blinding:


• Participants: [] Yes [] No [] Unclear [] Not applicable (e.g., difficult for dietary interventions)


• Intervention Personnel: [] Yes [] No [] Unclear [] Not applicable


• Outcome Assessors: [] Yes [] No [] Unclear [] Not applicable


• Data Analysts: [] Yes [] No [] Unclear [] Not applicable


• Reason for Blinding (if any):


• Effectiveness of Blinding (if assessed):


• Primary Objective(s) of the Study: (Briefly state)


• Sample Size Calculation Reported? [] Yes [] No [] Not Reported


• If yes, based on what primary outcome?


• Target sample size per group (if reported):

Part C: Participant Characteristics

• Total Number of Participants (at baseline):


• Population/Target Group: (e.g., Adults with T2DM, Pregnant women, Overweight children, General healthy population, Athletes)


• Inclusion Criteria (Key ones):


• Exclusion Criteria (Key ones):


• Mean Age (and SD/range):


• Sex/Gender (% Female):


• Ethnicity/Race (% for major groups):


• Socioeconomic Status (SES) Indicators (if reported): (e.g., income, education level)


• Baseline Health Status/Diagnosis: (e.g., BMI, comorbidity, specific health conditions, medication use)


• Baseline Anthropometrics (mean & SD):


• Weight (kg):


• BMI (kg/m²):


• Waist Circumference (cm):


• Body Fat (%):


• Baseline Dietary Intake (if reported): (e.g., typical calorie intake, macronutrient distribution, specific food group intake)


• Relevant Comorbidities/Medications (if applicable):


• Any other relevant characteristics:

Part D: Intervention Details (Experimental Group)

• Intervention Name/Type: (e.g., Mediterranean Diet, Low-Carb Diet, Omega-3 Supplementation, Dietary Counseling, Meal Replacement)


• Description of Intervention: (Be as detailed as possible)


• Key Components: (e.g., specific food groups, nutrient targets, recipes, educational materials, physical activity component, psychological support)


• Dosage/Quantity/Frequency (if applicable): (e.g., 200mg EPA/DHA daily, 2 meal replacements/day, weekly counseling session)


• Duration of Active Intervention: (e.g., 8 weeks, 6 months)


• Mode of Delivery: (e.g., Individual counseling, Group sessions, Online platform, Self-administered, Delivered meals/supplements)


• Provider of Intervention: (e.g., Registered Dietitian, Physician, Nurse, Health Coach, Peer, Self-directed)


• Intensity/Number of Contacts: (e.g., 6 weekly sessions, daily online check-ins)


• Fidelity/Adherence to Intervention: (How was it measured and what was reported?)


• Measure Used: (e.g., dietary recalls, supplement counts, attendance logs, self-report questionnaire)


• Reported Adherence: (% adherence, reasons for non-adherence)


• Co-interventions/Other Treatments: (e.g., standard medical care, concurrent exercise program)

Part E: Comparator Details (Control/Comparator Group)

• Comparator Name/Type: (e.g., Usual Care, Placebo, Waitlist Control, Alternative Nutrition Intervention, No Intervention, Attention Control)


• Description of Comparator: (Detail in the same way as the intervention)


• Key Components:


• Dosage/Quantity/Frequency (if applicable):


• Duration:


• Mode of Delivery:


• Provider:


• Intensity/Number of Contacts:


• Fidelity/Adherence (if applicable):


• Co-interventions/Other Treatments:


• Was the comparator standard of care in the study setting? [] Yes [] No [] Unclear

Part F: Outcome Measures & Results

For EACH relevant outcome:

• Outcome Category: (e.g., Anthropometric, Biochemical, Dietary Intake, Clinical, Quality of Life, Behavioral)


• Outcome Name: (e.g., Body Weight, HbA1c, Saturated Fat Intake, Blood Pressure, SF-36 score, Physical Activity Level)


• Primary or Secondary Outcome in original study? [] Primary [] Secondary


• Method of Measurement: (e.g., DEXA scan, Blood draw, 24-hr dietary recall, Validated questionnaire)


• Unit of Measurement: (e.g., kg, %, mmol/L, mg/dL, units)


• Time Point(s) of Measurement: (e.g., Baseline, Post-intervention (e.g., 12 weeks), Follow-up (e.g., 6 months))

• Statistical Analysis Method Used (for between-group differences): (e.g., ANOVA, ANCOVA, t-test, regression)


• Handling of Missing Data: (e.g., Imputation, Last Observation Carried Forward, Complete Case Analysis)


• Analysis Approach: [] Intention-to-Treat (ITT) [] Per-Protocol (PP) [] As-Treated [] Other (Specify)


• Dropouts/Loss to Follow-up:


• Intervention Group: N= [ ] (Reasons: )


• Comparator Group: N= [ ] (Reasons: )


• Any Subgroup Analyses? [] Yes [] No


• If yes, on what variable and what were the key findings?


• Other Relevant Findings/Narrative Results:

Part G: Adverse Events (AEs)

• Were adverse events reported/monitored? [] Yes [] No [] Not Reported


• Number of participants experiencing AEs:


• Intervention Group: N= [ ]


• Comparator Group: N= [ ]


• Description of AEs (type, severity, frequency):


• Serious AEs (if any):


• Withdrawals due to AEs:


• Intervention Group: N= [ ]


• Comparator Group: N= [ ]


• Were AEs considered related to the intervention?

Part H: Funding, Conflicts of Interest & Other Notes

• Source of Funding: (e.g., Government, Industry, Non-profit, University, Self-funded)


• Potential Conflicts of Interest (COI) declared by authors: [] Yes [] No [] Not Reported


• If yes, describe:


• Comments/Clarifications/Assumptions Made by Extractor: (e.g., "Assumed SD was reported since only Mean and SE were given; calculated SD from SE*sqrt(N).", "Unclear whether blinding was maintained.")


• Any major limitations noted by the authors?


• Any other relevant information not captured above:

Part I: Risk of Bias Assessment (Using a tool like Cochrane RoB 2.0 for RCTs or ROBINS-I for non-RCTs)

For EACH outcome, or overall for the study if appropriate by the tool:

Domain 1: Bias arising from the randomization process

• Judgment: [] Low risk [] Some concerns [] High risk


• Rationale:

• Judgment: [] Low risk [] Some concerns [] High risk


• Rationale:

• Judgment: [] Low risk [] Some concerns [] High risk


• Rationale:

• Judgment: [] Low risk [] Some concerns [] High risk


• Rationale:

• Judgment: [] Low risk [] Some concerns [] High risk


• Rationale:

Important Considerations & Tips:

• Pilot Testing is Crucial: Before you start extracting, take 2-3 studies (one easy, one medium, one complex/poorly reported) and extract data using this form. Do this independently with another reviewer, then compare and discuss discrepancies. This process will highlight ambiguities, missing fields, or unnecessary fields, allowing you to refine the form.


• Dual Extraction: Ideally, two independent reviewers should extract data from each study, with a third reviewer resolving any discrepancies. This minimizes errors and bias.


• "N/A" vs. "NR": Use "N/A" (Not Applicable) for fields that don't apply to the study type (e.g., randomization for an observational study). Use "NR" (Not Reported) for information that should be there but isn't explicitly stated in the paper.


• Specific to Your Review Questions: While comprehensive, tailor this form to your specific PICO (Population, Intervention, Comparator, Outcome) questions. For example, if you're only interested in weight loss, you might simplify the outcome section to focus heavily on that.


• Data Management: Consider using an electronic tool for data extraction, especially for a large number of studies. Spreadsheets (Excel, Google Sheets), or dedicated systematic review software like Covidence, Rayyan, or DistillerSR, can streamline the process, facilitate dual extraction, and make data analysis easier.


• Units: Be very explicit about units (e.g., kg, cm, mmol/L, mg/dL). Standardize units where possible (e.g., convert all blood glucose to mmol/L) or note the reported unit for later conversion during analysis.


• Qualitative Data: If your review includes qualitative data (e.g., from process evaluations, participant experiences), you'll need additional sections to extract themes, quotes, and findings relevant to those aspects.