How much food is "just right" for a healthy diet? Food-based dietary guidelines (FBDGs) provide recommendations on portion sizes worldwide, but the methods used to determine them vary widely. In a recent study published, researchers compared different approaches to food recommendations, revealing that geography and methodology significantly influence the suggested amounts for various food groups.
Dietary Guidelines
Dietary guidelines serve as essential public health tools, providing region-specific diet and portion size recommendations. These guidelines aim to improve population health by aligning nutrient needs with realistic food choices. Despite global efforts to standardize dietary advice, countries use different methods to develop their FBDGs, ranging from expert consensus to complex data-driven modeling.
Historically, dietary recommendations were primarily based on expert opinions and reviews of nutritional studies. However, advancements in food consumption data collection and statistical modeling have allowed for more precise, data-based approaches. Some countries incorporate national food surveys to tailor portion sizes to local eating habits, while others rely on international standards.
Despite these efforts, there is no universal method for determining portion sizes, leading to inconsistencies between regions. The study found that while different methodologies exist, only 15 out of 96 FBDGs used data-driven modeling, with the majority relying on expert opinion and literature reviews. This indicates a significant gap in integrating national dietary data into food guidelines. These variations raise questions about the impact of different approaches on dietary adherence and overall public health, also highlighting the need for more coordinated efforts in FBDG development.
Investigating Dietary Recommendation Variations
The present study examined how different countries develop quantitative dietary recommendations, focusing on the methodologies used to determine portion sizes. The researchers collected data from 96 national FBDGs through the Food and Agriculture Organization (FAO) repository and other sources. They categorized the approaches into three main groups — expert consensus and literature reviews, minimal calculations, and data-driven models involving national dietary intake surveys.
To compare the effects of these methods, the study extracted recommended portion sizes for 15 food groups across different regions. The researchers then analyzed whether the methodology influenced the portion sizes suggested in dietary guidelines. Beyond methodological differences, the study also identified economic and cultural factors, such as the cost and availability of certain foods, as major contributors to variation in portion size recommendations.
Data were manually extracted, translated whenever necessary, and analyzed using statistical tests to identify significant differences between methodologies and across global regions, with adjustments for multiple comparisons.
The study aimed to determine whether data-driven approaches produced significantly different portion size recommendations compared to expert-driven methods. It also assessed whether differences in regional dietary habits influenced the suggested portion sizes. By systematically categorizing and comparing methodologies, the study also sought to identify trends that could inform future improvements in dietary guideline development.
Conclusion
The study highlighted the complexities of developing dietary guidelines and the need for greater harmonization in portion size recommendations. Despite methodological differences, the study found broad consistency in portion size recommendations across regions, suggesting a potential for greater harmonization in global dietary guidelines.
The results indicated that while different methodologies produce broadly similar results, regional factors and data limitations still influence dietary guidance. Future studies should focus on improving data collection and exploring how cultural and economic factors shape dietary habits to ensure that FBDGs are both scientifically sound and practical for diverse populations. Additionally, emerging approaches, such as machine learning and metabolomics, could further refine food recommendations and improve the integration of dietary data into national guidelines.
Source:
https://www.news-medical.net/news/20250302/Portion-sizes-vary-worldwide-but-science-isne28099t-the-reasone28094new-study-explains-why.aspx