Can children and adolescents use photographs of food to estimate portion sizes?

Objective: To test the effect of image size and presence of size cues on the accuracy of portion size estimation by children. Design: Children were randomly assigned to seeing images with or without food size cues (utensils and checked tablecloth) and were presented with sixteen food models (foods commonly eaten by children) in varying portion sizes, one at a time. They estimated each food model's portion size by selecting a digital food image. The same food images were presented in two ways: (i) as small, graduated portion size images all on one screen or (ii) by scrolling across large, graduated portion size images, one per sequential screen. Setting: Laboratory-based with computer and food models. Subjects: Volunteer multi-ethnic sample of 120 children, equally distributed by gender and ages (8 to 13 years) in [2008][2009]. Results: Average percentage of correctly classified foods was 60?3 %. There were no differences in accuracy by any design factor or demographic characteristic. Multiple small pictures on the screen at once took half the time to estimate portion size compared with scrolling through large pictures. Larger pictures had more overestimation of size. Conclusions: Multiple images of successively larger portion sizes of a food on one computer screen facilitated quicker portion size responses with no decrease in accuracy. This is the method of choice for portion size estimation on a computer.

“…No age-related differences in accuracy were reported in other studies (9,12,15) . No significant differences in accuracy or time were detected by gender, similar to other studies (17) .…”

Section: Discussioncontrasting

confidence: 52%

Children’s accuracy of portion size estimation using digital food images: effects of interface design and size of image on computer screen

Baranowski

Watson

et al. 2010

“…In addition, its been found that consumers can be sceptical of food photographs when displayed on food packaging with the belief that they are for marketing purposes only (5) . In contrast, food photographs were found to be relatively accurate PSEA for use with children (28)(29)(30) . Nevertheless, there are no validated alternative PSEA for composite foods.…”

Section: Discussionmentioning

confidence: 74%

An evaluation of portion size estimation aids: precision, ease of use and likelihood of future use

Faulkner

Livingstone

Pourshahidi

et al. 2016

Objective: The present study aimed to evaluate the precision, ease of use and likelihood of future use of portion size estimation aids (PSEA). Design: A range of PSEA were used to estimate the serving sizes of a range of commonly eaten foods and rated for ease of use and likelihood of future usage. Setting: For each food, participants selected their preferred PSEA from a range of options including: quantities and measures; reference objects; measuring; and indicators on food packets. These PSEA were used to serve out various foods (e.g. liquid, amorphous, and composite dishes). Ease of use and likelihood of future use were noted. The foods were weighed to determine the precision of each PSEA. Subjects: Males and females aged 18-64 years (n 120). Results: The quantities and measures were the most precise PSEA (lowest range of weights for estimated portion sizes). However, participants preferred household measures (e.g. 200 ml disposable cup) -deemed easy to use (median rating of 5), likely to use again in future (all scored either 4 or 5 on a scale from 1 = 'not very likely' to 5 = 'very likely to use again') and precise (narrow range of weights for estimated portion sizes). The majority indicated they would most likely use the PSEA preparing a meal (94 %), particularly dinner (86 %) in the home (89 %; all P < 0·001) for amorphous grain foods. Conclusions: Household measures may be precise, easy to use and acceptable aids for estimating the appropriate portion size of amorphous grain foods.

“…These studies, and numerous others not from South Asia (24)(25)(26)(27)(28)(29)(30)(31)(32)(33) , have reported bias (percentage error), percentage of correct photographs selected, ratios between estimated and weighed portions and/or correlations between weighed and recall methods. These are important measures for tools that are developed to aid the estimation of group-level mean nutrient intakes and risks of nutrient deficiency (5) .…”

mentioning

confidence: 88%

Development and validation of a photographic food atlas for portion size assessment in the southern plains of Nepal

Harris‐Fry

Paudel

Karn

et al. 2016

Objective: To develop and validate a photographic food atlas of common foods for dietary assessment in southern Nepal. Design: We created a life-sized photographic atlas of forty locally prepared foods. Between March and June 2014, data collectors weighed portion sizes that respondents consumed during one mealtime and then a different data collector revisited the household the next day to record respondents' estimations of their previous day's intakes using the atlas. Validity was assessed by percentage error, Cohen's weighted kappa (κ w ) and Bland-Altman limits of agreement. Setting: Dhanusha and Mahottari districts in southern Nepal. Subjects: A random sample of ninety-five adults in forty-eight rural households with a pregnant woman. Results: Overall, respondents underestimated their intakes (mean error = − 4·5 %). Rice and dal (spiced lentil soup) intakes were underestimated (−14·1 % and −34·5 %, respectively), but vegetable curry intake was overestimated (+20·8 %). Rice and vegetable curry portion size images were significantly reliably selected (Cohen's κ w (SE): rice = 0·391 (0·105); vegetable curry = 0·430 (0·139)), whereas dal images were not. Energy intake over one mealtime was under-reported by an average of 569 kJ (136 kcal; 4·5 % error) using recall compared with the weighing method. Conclusions: The photographic atlas is a useful tool for field estimation of dietary intake. Average errors were low, and there was 'modest' agreement between weighed and recalled portion size image selection of rice and vegetable curry food items. Error in energy estimation was low but with wide limits of agreement, suggesting that there is scope for future work to reduce error further.