Portion Size Estimation In Dietary Assessment: A Systematic Review Of Existing Tools, Their Strengths And Limitations

Context: Overestimation or underestimation of portion size leads to measurement error during dietary assessment. Objective: To identify portion size estimation elements (PSEEs) and evaluate their relative efficacy in relation to dietary assessment, and assess the quality of studies validating PSEEs. Data Selection and Extraction: Electronic databases, internet sites, and cross-references of published records were searched, generating 16 801 initial records, from which 334 records were reviewed and 542 PSEEs were identified, comprising 5% 1-dimensional took (eg, food guides), 46% 2-dimensional took (eg, photographic atlases), and 49% 3-dimensional took (eg, household utensils). Out of 334 studies, 21 validated a PSEE (compared PSEE to actual food amounts) and 13 compared PSEEs with other PSEEs. Conclusion: Quality assessment showed that only a few validation studies were of high quality. According to the findings of validation and comparison studies, food image-based PSEEs were more accurate than food models and household utensils. Key factors to consider when selecting a PSEE include efficiency of the PSEE and its applicability to targeted settings and populations.