Researchers in Turkey developed and tested a new food questionnaire called the TDG-SFFQ that accurately measures what Turkish adults eat. According to Gram Research analysis of 420 participants, the questionnaire showed moderate to strong agreement with detailed 24-hour food recalls for energy and nutrients, and produced consistent results when used twice four weeks apart. This tool can help health professionals reliably assess dietary intake in Turkish populations.
Researchers in Turkey created and tested a new questionnaire to measure what people eat. According to Gram Research analysis, this tool, called the TDG-SFFQ, asks adults about their food habits and compares well with other methods of tracking diet. The study involved 420 adults and showed the questionnaire accurately captures eating patterns. This matters because having reliable tools to measure diet helps doctors and nutritionists understand how food choices affect health in different populations.
Key Statistics
A 2026 validation study of 420 Turkish adults found that the TDG-SFFQ questionnaire showed moderate to strong correlation with 24-hour dietary recall for measuring energy and macronutrient intake.
When 56 participants completed the TDG-SFFQ twice over four weeks, intraclass correlation coefficients exceeded 0.666, indicating strong reliability and consistency of the dietary assessment tool.
Micronutrient measurements from the TDG-SFFQ remained within 95 percent confidence intervals when compared to 24-hour recall data, demonstrating acceptable agreement across vitamin and mineral intake estimates.
The Quick Take
- What they studied: Whether a new food questionnaire designed for Turkish adults accurately measures what people eat and whether it gives consistent results when used multiple times.
- Who participated: 420 Turkish adults between ages 19 and 64 living in Ankara. Researchers recruited people through social media and professional networks, asking participants to tell them about their eating habits.
- Key finding: The new questionnaire showed moderate to strong agreement with a detailed 24-hour food recall method for measuring energy and nutrients. When tested again after 4 weeks, results were consistent and reliable.
- What it means for you: If you live in Turkey or work with Turkish populations, this questionnaire could help track dietary patterns more accurately. However, this is a research tool primarily for health professionals and researchers, not for personal use.
The Research Details
Researchers created a food frequency questionnaire, which is a list of common foods with portion sizes that people answer about their eating habits. They tested it with 420 Turkish adults using face-to-face interviews. To check if the questionnaire was accurate, they compared answers from the questionnaire with detailed food records from a single day (24-hour recall). They also tested whether the questionnaire gave similar answers when people answered it twice, four weeks apart, with 56 participants. This approach helps researchers understand if the tool measures diet consistently and correctly.
Different countries have different foods and eating patterns, so diet measurement tools need to be designed for specific populations. A questionnaire that works well in one country might not work as well in another. Creating a tool specifically for Turkish adults ensures that health researchers can accurately measure diet in this population, which is important for studying how food affects health outcomes.
The study used established statistical methods to compare results between the questionnaire and the 24-hour recall. The researchers calculated correlation coefficients, which measure how closely two methods agree. They also used Bland-Altman plots, a visual method to check agreement. Results showed strong statistical significance (p less than 0.05), meaning the findings are unlikely due to chance. However, the reliability testing involved only 56 participants, which is smaller than the main study group.
What the Results Show
The TDG-SFFQ questionnaire showed moderate to strong correlation with the 24-hour dietary recall method for measuring energy intake and macronutrients (protein, carbohydrates, and fats). This means when people answered the questionnaire, their reported food intake matched reasonably well with what they reported eating in detailed 24-hour recalls. For micronutrients like vitamins and minerals, the results clustered around the average, staying within the expected range of variation. When the same 56 participants answered the questionnaire twice, four weeks apart, the results were highly consistent, with correlation coefficients exceeding 0.666, indicating strong reliability.
The graphical analysis using Bland-Altman plots showed that micronutrient measurements remained within acceptable limits of agreement. This visual method helps researchers see if the questionnaire tends to overestimate or underestimate intake. The results suggest the tool performs consistently across different nutrient categories. The face-to-face interview method appeared to work well for collecting accurate responses from participants.
Food frequency questionnaires have been used in nutrition research for decades, but most were developed for Western populations. This study adds to the growing body of research showing that culturally adapted dietary assessment tools are needed for different populations. The validation approach used here follows international standards for dietary assessment tool development, making results comparable to similar studies in other countries.
The reliability testing included only 56 of the 420 participants, which is a smaller sample for that part of the study. The study only included adults ages 19 to 64, so results may not apply to older adults or teenagers. Participants were recruited through social media and professional networks, which may mean they were more educated or health-conscious than the general population. The study was conducted only in Ankara, so results may not represent all regions of Turkey with different food availability and eating customs.
The Bottom Line
Health professionals and researchers working with Turkish populations can use this questionnaire with confidence for measuring dietary intake in research studies. The tool is most appropriate for adults ages 19 to 64. It should be administered by trained interviewers through face-to-face meetings to ensure accuracy. This is a research tool, not a personal diet tracking app, so it’s best used by professionals in clinical or research settings.
Nutritionists and doctors working in Turkey or with Turkish immigrant populations should know about this tool. Public health researchers studying diet and disease in Turkish adults can use this questionnaire. Food companies and government agencies developing nutrition policies for Turkey may find this useful. Individual people tracking their own diet should use simpler, consumer-friendly apps rather than this research tool.
This questionnaire provides a snapshot of eating habits at one point in time. For tracking changes in diet over months or years, researchers would need to administer the questionnaire multiple times. Results from a single administration can be compared with 24-hour recalls to validate individual dietary patterns.
Frequently Asked Questions
How accurate is the TDG-SFFQ questionnaire for measuring diet?
The TDG-SFFQ showed moderate to strong agreement with 24-hour dietary recalls for energy and macronutrients in 420 Turkish adults. Micronutrient measurements also remained within acceptable ranges, making it a reliable tool for dietary assessment in this population.
Can I use this food questionnaire to track my own diet?
The TDG-SFFQ is designed as a research tool for health professionals and researchers, not for personal use. It requires face-to-face interviews with trained staff. For personal diet tracking, consumer-friendly nutrition apps are more practical and user-friendly.
Does this questionnaire work for all Turkish people?
The study included adults ages 19 to 64 in Ankara, so results apply best to this age group and region. It may not accurately represent teenagers, older adults, or people in other regions of Turkey with different food availability and eating customs.
How often should the questionnaire be used to track dietary changes?
The questionnaire provides a snapshot of eating habits at one point in time. For tracking changes over months or years, health professionals would administer it multiple times, typically every 3 to 6 months, to monitor long-term dietary patterns.
What makes this questionnaire better than other diet measurement methods?
This questionnaire was specifically designed for Turkish adults based on Turkish dietary guidelines, making it culturally appropriate. It showed strong reliability when tested twice and good agreement with detailed food records, making it more accurate for this population than generic tools.
Want to Apply This Research?
- Users could log their food intake weekly using categories from the TDG-SFFQ, such as grains, vegetables, fruits, dairy, and proteins, then compare their patterns monthly to see if they’re meeting Turkish dietary guidelines.
- An app could use this questionnaire structure to help Turkish users identify which food groups they eat too much or too little of compared to recommendations, then suggest specific foods to add or reduce.
- Administer the questionnaire every 3 to 6 months to track long-term changes in dietary patterns. Compare results over time to see if dietary interventions are working. Use the results to adjust personalized nutrition recommendations.
This research describes a tool for measuring dietary intake in research and clinical settings. It is not a substitute for personalized nutrition advice from a registered dietitian or healthcare provider. Individual dietary needs vary based on age, health status, activity level, and medical conditions. Anyone making significant dietary changes should consult with a qualified healthcare professional. This questionnaire is designed for Turkish adults ages 19 to 64 and may not apply to other populations or age groups.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.