Portion size estimation in dietary assessment: a systematic review of existing tools, their strengths and limitations

Abstract

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 tools (eg, food guides), 46% 2-dimensional tools (eg, photographic atlases), and 49% 3-dimensional tools (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.

Development and evaluation of image-series for portion size estimation in dietary assessment among adults

“…A strength in the present validation study is the use of pre-weight foods as the reference tool, which is in line with Amoutzopoulos et al recommendations for validating portion size estimation tools (7) .…”

“…Portion size estimates is a critical element in dietary assessment (3–6) . A recent systematic review by Amoutzopoulos et al shows that there is a lack of validated portion size estimation tools, and consequently a pressing need for more validation studies (7) .…”

“…food models and household measures, have been largely replaced by digital images of portion sizes. Importantly, food images have been shown to be more accurate compared with food models and household utensils in the review by Amoutzopoulos et al (7) Further, two studies included in their review compared digital images and printed images, and reported no statistical difference in accuracy between these image types (16,17) . It is established that the number of images in an image-series affects the portion size estimation accuracy, favouring a high number of images (18,19) , which is more convenient when using a digital format v. printed images.…”

Evaluation of the Ability of Diet-Tracking Mobile Applications to Estimate Energy and Nutrient Intake in Japan

“…Portion size estimation is important since misreporting of the consumed amount is a major source of measurement error when assessing dietary intake [44,[48][49][50]. In this study, all apps estimated the amount of food consumed based on the relative portion size entered by users.…”

Development and validation of the FiberScreen: A short questionnaire to screen fibre intake in adults

“…Future research needs to focus on portion size estimations, which are a major cause of measurement error in most types of dietary assessment 55 . Recent research has suggested that a text‐based description of portion sizes is more accurate than image‐based descriptions 56 ; however, this conflicts with the conclusions of a recent systematic review 57 . This indicates the complexity of portion size estimation, and the need for more research.…”