Diet is a major lifestyle-related risk factor for chronic diseases. Dietary intake can be assessed through subjective reports or objective observations. Subjective methods include food frequency questionnaires (FFQ), 24-hour dietary recalls (24HR), and dietary records (DR), while objective methods involve duplicate diet samples or food consumption records. Each method has strengths and limitations. FFQs are widely used in epidemiological studies but have been questioned for accuracy. Recent advancements include computer-based and web-based technologies that improve data collection and reduce respondent burden. These technologies allow for more accurate and efficient dietary assessments but require significant resources and technical expertise. Despite these improvements, challenges remain, such as data entry errors, recall bias, and the need for training. Dietary history is another method used for long-term intake assessment but is less common in epidemiological studies. Newer technologies, such as mobile apps and wearable devices, offer innovative ways to collect dietary data but are still in experimental stages. While FFQs remain widely used, their accuracy is often lower than that of 24HR or DR. Combining multiple methods, such as FFQ with DR or biomarkers, can improve the accuracy of dietary intake estimates. Overall, dietary assessment methods continue to evolve, with a focus on improving accuracy, feasibility, and the ability to collect real-time data. However, challenges related to self-reporting and technological limitations persist. The choice of method depends on the study's objectives, resources, and the population being studied.Diet is a major lifestyle-related risk factor for chronic diseases. Dietary intake can be assessed through subjective reports or objective observations. Subjective methods include food frequency questionnaires (FFQ), 24-hour dietary recalls (24HR), and dietary records (DR), while objective methods involve duplicate diet samples or food consumption records. Each method has strengths and limitations. FFQs are widely used in epidemiological studies but have been questioned for accuracy. Recent advancements include computer-based and web-based technologies that improve data collection and reduce respondent burden. These technologies allow for more accurate and efficient dietary assessments but require significant resources and technical expertise. Despite these improvements, challenges remain, such as data entry errors, recall bias, and the need for training. Dietary history is another method used for long-term intake assessment but is less common in epidemiological studies. Newer technologies, such as mobile apps and wearable devices, offer innovative ways to collect dietary data but are still in experimental stages. While FFQs remain widely used, their accuracy is often lower than that of 24HR or DR. Combining multiple methods, such as FFQ with DR or biomarkers, can improve the accuracy of dietary intake estimates. Overall, dietary assessment methods continue to evolve, with a focus on improving accuracy, feasibility, and the ability to collect real-time data. However, challenges related to self-reporting and technological limitations persist. The choice of method depends on the study's objectives, resources, and the population being studied.