Portion Size Estimation Research Articles

Validation of a digitally displayed photographic food portion-size estimation aid among women in urban and rural Malawi.

To validate digitally displayed photographic portion-size estimation aids (PSEA) against a weighed meal record and compare findings with an atlas of printed photographic PSEA and actual prepared-food PSEA in a low-income country. Participants served themselves water and five prepared foods, which were weighed separately before the meal and again after the meal to measure any leftovers. Participants returned the following day and completed a meal recall. They estimated the quantities of foods consumed three times using the different PSEA in a randomized order. Two urban and two rural communities in southern Malawi. Women (n 300) aged 18-45 years, equally divided by urban/rural residence and years of education (≤4 years and ≥5 years). Responses for digital and printed PSEA were highly correlated (>91 % agreement for all foods, Cohen's κw = 0·78-0·93). Overall, at the individual level, digital and actual-food PSEA had a similar level of agreement with the weighed meal record. At the group level, the proportion of participants who estimated within 20 % of the weighed grams of food consumed ranged by type of food from 30 to 45 % for digital PSEA and 40-56 % for actual-food PSEA. Digital PSEA consistently underestimated grams and nutrients across foods, whereas actual-food PSEA provided a mix of under- and overestimates that balanced each other to produce accurate mean energy and nutrient intake estimates. Results did not differ by urban and rural location or participant education level. Digital PSEA require further testing in low-income settings to improve accuracy of estimations.

Avaliação da percepção do tamanho de porções de alimentos proteicos

Introdução: A avaliação quantitativa do consumo de proteínas utilizando instrumentos como o recordatório de 24 horas e registro alimentar pode ser subestimada ou superestimada devido às falhas na estimativa do tamanho das porções de alimentos proteicos. Objetivo: Avaliar a percepção do tamanho das porções de alimentos proteicos. Materiais e Métodos: A amostra foi composta por 50 universitários que estimaram o tamanho das porções dos seguintes alimentos proteicos: bife bovino grelhado, carne bovina cozida em pedaços, carne bovina moída refogada, filé de peito de frango grelhado e frango cozido em cubos. Os alimentos foram dispostos em cabines individuais. Em cada cabine foi colocada uma porção média (100 g) do alimento em um prato raso. Resultados: O percentual de sujeitos que indicaram o tamanho exato das porções (médio) variou de 52,0 a 66,0%. A estimativa do tamanho médio das porções em gramas foi superestimada para todos os alimentos, especialmente para o bife bovino (174,5 g). Conclusão: Os resultados mostraram que maioria dos sujeitos estimou corretamente o tamanho das porções de alimentos proteicos categorizadas em pequena, media e grande, mas o percentual de sujeitos que estimou erroneamente é expressivo e pode afetar a qualidade dos dados sobre consumo de proteínas.

Optimizing portion-size estimation aids: a formative evaluation in Malawi.

To investigate preferences for and ease-of-use perceptions of different aspects of printed and digitally displayed photographic portion-size estimation aids (PSEA) in a low-resource setting and to document accuracy of portion-size selections using PSEA with different visual characteristics. A convergent mixed-methods design and stepwise approach were used to assess characteristics of interest in isolation. Participants served themselves food and water, which were weighed before and after consumption to measure leftovers and quantity consumed. Thirty minutes later, data collectors administered a meal recall using a PSEA and then a semi-structured interview. Blantyre and Chikwawa Districts in the southern region of Malawi. Ninety-six women, aged 18-45 years. Preferences and ease-of-use perceptions favoured photographs rather than drawings of shapes, three and five portion-size options rather than three with four virtual portion-size options, a 45° rather than a 90° photograph angle, and simultaneous rather than sequential presentation of portion-size options. Approximately half to three-quarters of participants found the portion-size options represented appropriate amounts of foods or water consumed. Photographs with three portion sizes resulted in more accurate portion-size selections (closest to measured consumption) than other format and number of portion-size option combinations. A 45° angle and simultaneous presentation were more accurate than a 90° angle and sequential presentation of images. Results from testing PSEA visual characteristics separately can be used to generate optimal PSEA, which can improve participants' experiences during meal recalls.

OpenDRS: An Open-source 24-hour Recall for Mobile Devices (P13-004-19)

ObjectivesOur aim was to develop a 24-hour recall program using open-source language that can be readily adapted for use on multiple platforms and in different settings. MethodsWe developed the Open Dietary Recall System (OpenDRS), a multi-pass, 24-hour recall survey using the XLSForm programming language. XLSForm operates in Microsoft Excel and is used by several free or subscription-based electronic survey platforms that deploy forms via Android devices or online. The first pass collects a brief list of foods consumed, the second pass collects descriptive details and added ingredients for each food, and the third pass collects portion size estimates. The final pass reviews the recorded data with the option to edit or add foods. The program references external food and ingredient lists in .csv format. These food and ingredient lists are customizable for each survey setting, can be coded to match nutrient composition or recipe tables, and can be amended over the course of a study. Questions or response options can be added or edited to fit study-specific data collection methods. Photos can be incorporated for food identification or portion size estimation. Two case studies from adaptations in Malawi and Haiti will be presented. ResultsOpenDRS was used to collect 24-hour dietary intake data among 6- to 15-month-old children in Malawi, for a randomized, controlled complementary feeding trial. The median number of foods reported was 6, and the median survey duration was 9 minutes. For a national nutrition survey of 6- to 59-month-old children and their caregivers in Haiti, the program was expanded to record recipe data and to capture caregiver and child intakes in one electronic survey form. Recipes reported during the caregiver’s recall can be linked to the child’s recall if both consumed the same mixed dish. ConclusionsOpenDRS is an open-source 24-hour recall program which has been used in low- and middle-income countries. The XLSForm program for data collection and Stata code for data formatting will be made available to researchers conducting nutrition surveys via the Open Science Framework. Funding SourcesThe Bill & Melinda Gates Foundation and GAIN.

Validation of a Digitally Displayed Photographic Food Portion Size Estimation Aid Among Women in Urban and Rural Malawi (P13-012-19)

ObjectivesEasy-to-use tools to facilitate portion size estimation in low-income countries are needed. The objective of this study was to validate digitally displayed photographic portion size estimation aids (PSEAs) against a weighed meal record and compare findings with an atlas of printed photographic PSEAs and actual prepared food PSEAs in a low-income country. MethodsIn Blantyre and Chikwawa Districts, Malawi, we enrolled 300 women 18–45 years of age equally divided by urban/rural residence and years of education (≤4 years and >4 years). Participants served themselves water and five prepared foods, which were weighed separately before the meal and again after the meal to measure any leftovers. Participants returned the following day and completed a meal recall. They estimated the quantities of foods consumed three times using the different PSEAs in a randomized order. ResultsResponses for digital and printed PSEAs were highly correlated (>91% agreement for all foods, Cohen’s κ = 0.78–0.93). Overall, digital and actual-food PSEAs had a similar level of agreement with the weighed meal record at the group level. The proportion of participants who estimated within 20% of the weighed grams of food consumed ranged by type of food from 30–45% for digital PSEAs and 40–56% for actual food PSEAs. Digital PSEAs consistently underestimated grams and nutrients across foods, whereas actual-food PSEAs provided a mix of under- and overestimates that balanced each other to produce accurate mean energy and nutrient intake estimates. Results did not differ by urban and rural location or participant education level. ConclusionsDigital PSEAs require further testing in low-income settings to improve accuracy of estimations because they offer several logistical advantages over other PSEAs. Funding SourcesRTI International.

Role of metabolomics in identification of biomarkers related to food intake.

Dietary assessment methods including FFQ and food diaries are associated with many measurement errors including energy under-reporting and incorrect estimation of portion sizes. Such errors can lead to inconsistent results especially when investigating the relationship between food intake and disease causation. To improve the classification of a person's dietary intake and therefore clarify proposed links between diet and disease, reliable and accurate dietary assessment methods are essential. Dietary biomarkers have emerged as a complementary approach to the traditional methods, and in recent years, metabolomics has developed as a key technology for the identification of new dietary biomarkers. The objective of this review is to give an overview of the approaches used for the identification of biomarkers and potential use of the biomarkers. Over the years, a number of strategies have emerged for the discovery of dietary biomarkers including acute and medium term interventions and cross-sectional/cohort study approaches. Examples of the different approaches will be presented. Concomitant with the focus on single biomarkers of specific foods, there is an interest in the development of biomarker signatures for the identification of dietary patterns. In the present review, we present an overview of the techniques used in food intake biomarker discover, including the experimental approaches used and challenges faced in the field. While significant progress has been achieved in the field of dietary biomarkers in recent years, a number of challenges remain. Addressing these challenges will be key to ensure success in implementing use of dietary biomarkers.

Photo-Assisted Dietary Method Improves Estimates of Dietary Intake Among People with Sleeve Gastrectomy.

Bariatric operations are effective obesity treatments because of the significant reductions in food intake after surgery, but weight regain remains a problem in a small group of patients after surgery. Estimating food intake is difficult due to dieting status, weight, gender, and challenges with estimating portion size. We aimed to evaluate the use of digital food photography in comparison to conventional methods among patients after sleeve gastrectomy. Participants used a mobile device (mHealth) to photo-document their dietary intake of all food and beverages consumed before and after eating. They also completed a 24h food recall interview with a dietician. Data from 383 eating occasions were analyzed. Food intake using 24h recall was reported as 972.5 ± 77kcal and estimates from photographs were 802.9 ± 63.4kcal, with a difference of 169.6 ± 451.4kcal (95% confidence interval (CI) of 41.4 to 297.9kcal, p = 0.005). There was no difference for protein intake, but carbohydrate intake reported during the 24h recall was 541.2 ± 298kcal and estimates from photographs were 395.2 ± 219.6kcal, with a difference of 145.8 ± 256.3kcal (95% CI of 73.2 to 218.8kcal, p = 0.0001). After sleeve gastrectomy, patients reported eating more total calories and calories from carbohydrates compared to estimations using photographs. The implication for patients are that tools such as mHealth might be useful to optimize food intake and calories after sleeve gastrectomy, especially for those patients that may struggle with weight regain after surgery.

The Role of Various Forms of Training on Improved Accuracy of Food-Portion Estimation Skills: A Systematic Review of the Literature.

This study describes the types of food-portion tools used and changes in accuracy for food-portion size estimation by adult populations after an intervention of food-portion education and training. This systematic review searched 7 scientific databases. Only internally comparable study designs were included. Studies were tabulated for nutrition- and non-nutrition-trained university students and the general population. Included studies were assessed for level of evidence and quality, including risk of bias. Thirteen studies were reviewed, with 8 targeting university students. Food type, length of training, number of tools, and the impact of repeated use on food-portion estimation were summarized. Estimation accuracy calculations across studies were not consistent, and training was found to improve portion-size estimation accuracy in the short term (4 wk). Computer-based training tools only identified for the general population were equally or less effective and shifted estimation from under- to overestimation. This review suggests that education with food-portion tools may be effective in improving estimation skills in university-recruited participants and the general population. Computerized tools for university students are required, likely combined with other tools for improved estimation accuracy. The use of food models or multiple tools is more effective until a tailored computerized solution is developed. Repeated training is needed to maintain skills over time. This systematic review was registered with PROSPERO at http://bit.ly/2mZK3u3 as CRD42016038110.

Reporting children\u2019s food consumption: a comparison of reliability between a 2-day food record and a 7-day food diary

BackgroundMonitoring eating behavior of children is critical to understanding risks for developing nutrition-related diseases in later life. While accurately assessing children’s food intake is important, collecting reliable data about children’s food intake remains challenging. Limited validated tools exist, and issues of dietary intake assessment such as recall accurateness, portion size estimation, and participant burden persist. In a previous study conducted in Switzerland, a 7-day food diary assessing eating behavior of school-aged children was developed and tested for reliability, showing high levels of agreement between parents and children. In this study, a shorter, 2-day food consumption record was developed and tested. The objective of this study was to compare the reliability of the two instruments, measuring the level of agreement between children and their parents when reporting a child’s food consumption.MethodsA cross-sectional study was conducted in Switzerland (April–June 2014) among 589 children and one of their parents, where 299 completed a 7-day diary and 290 completed a 2-day tick box record. Children and parents independently reported what the child ate at six eating occasions. To assess agreement, Cohen’s Kappa, Kendall’s tau-b and Spearman’s non-parametric correlations were used. Lin’s concordance correlation coefficient and corresponding 95% confidence interval was also computed.ResultsWith the 2-day food record, Kendall’s tau-b correlations ranged from 0.66 (whole grains) to 0.85 (proteins). Kappa values showed moderate to substantial agreement for all food categories, ranging from 0.47 for dairy products to 0.75 for fat meat and fast food. Agreement between child’s and parent’s reporting was similar for both genders. Large Kendall’s tau-b and Spearman’s correlations were found for almost all foods in all school grades.ConclusionsThe 2-day tick box food record showed a higher level of agreement between parents and children of all ages (7–14) and for both genders as compared to the 7-day food diary. Moreover, the 2-day food record tool simplifies data collection and data entry procedures, while providing reliable data about children’s food intake. Thus, this instrument could be used to reliably collect food intake directly from children without parental involvement.

Dietary assessment of pre-diabetic patients by using food frequency questionnaire. A systematic review of study quality, study outcome, study questionnaire and their relative validity and reliability

The contribution of dietary factors in the development and progression of pre-diabetes has been increasingly recognized. However, due to high variability in dietary habits measurement of dietary intake remains one of the most challenging tasks in this population. Food frequency questionnaire (FFQ) which investigates usual dietary intake can be used to identify frequent consumption of foods such as dietary fat, fiber, grains that are linked to the risk of pre-diabetes. This systematic review was conducted to identify and describe FFQs that measure dietary intake of pre-diabetic patients and to examine their relative validity and reliability. The systematic search was done through electronic databases such as PubMed, CINAHL, PsycINFO, ProQuest and Scopus. Methodological quality of included studies and results of study outcome was also summarized in this review. The search identified 445 papers, of which 18 studies reported 15 FFQs, met inclusion criteria. Most of the FFQs (n=12) were semi-quantitative while three were frequency measures with portion size estimation of selected food items. Test-retest reliability of FFQ was reported in 7 (38.3%) studies with the correlation coefficient of 0.33-0.92. Relative validity of FFQ was reported in 16 (88.8%) studies with the range of correlation coefficient of 0.08-0.83. Dietary patterns rich in carbohydrate, fat, animal protein and n-3 fatty acids were associated with increased risk of pre-diabetes. No well-established disease-specific FFQ identified in the literature. Development of a valid, practical and reliable tool is needed for better understanding of the impact of diet in pre-diabetic population.

Examining the Accuracy and Use of Portion Size Estimation Aids in Parents of Children With Obesity: A Randomized Controlled Trial

ObjectiveTo determine parents’ (1) accuracy in using portion size estimation aids (PSEAs) to estimate portion sizes and (2) use of PSEAs at home. MethodsParents (n = 37) of children in a pediatric weight management clinic were recruited, enrolled in a parallel-design, randomized, controlled trial, and assigned to receive a 2-dimensional (2D) or 3D PSEA. Percent absolute estimation accuracy was examined across groups and food types. Survey responses were organized according to frequencies and percentages were calculated. ResultsMain effects of group, food type, and group × food type interaction were significant (all P < .05). The 2D PSEAs yielded more accurate estimates of portion sizes for amorphous foods. Overall, parents’ estimation accuracy was poor. Participants were satisfied and found the PSEAs to be useful. Conclusions and ImplicationsThe 2D PSEAs led to greater accuracy in estimating portions of amorphous foods. Parents showed poor accuracy in estimating portion sizes. This study highlights the role of dietitians and nutrition educators in enhancing portion estimation accuracy.

Nutrient consumption and associated factors among school age children in Dewa Chefe District, northeast Ethiopia: a cross-sectional study

BackgroundInadequate nutrient consumption causes protein energy malnutrition and micronutrient deficiencies and related consequences, including poor physical growth and intellectual development. However, literatures showing quantitative measurement of dietary intake of children are limited in Ethiopia. Therefore, this study investigated nutrient consumption and associated factors among school age children (7–9 years) in Dewa Cheffe District, northeast of Ethiopia.MethodsA community based cross-sectional study was conducted from November to December, 2015 in Dewa Cheffe District. A multistage sampling technique was used to select 605 study subjects. Pre-tested and structured questionnaire was used to collect data. A 24-h dietary recall with portion size estimation method was used to assess nutrient consumption of school age children. Multivariable logistic regression analysis was fitted to identify factors associated with inadequate energy intake. adjusted odds ratio (AOR) with corresponding 95% confidence interval was computed to show the strength of association. In multivariable analysis, a P value of < 0.05 was used to declare statistically significance.ResultsA total of 600 school age children were included in the study. About 29% [95%, CI 21.9, 36.1] of study participants had inadequate energy intake. The result of multivariable analysis revealed that, children who were belonged to a female headed households [AOR = 3.65; 95% CI 1.20, 11.04] and family size of six and above [AOR = 14.42; 95% CI 4.65, 44.67] were found with increased odds of inadequate energy consumption. In contrast, decreased odds of inadequate energy consumption were observed among children whose mothers were housewives [AOR = 0.32; 95% CI 0.11, 0.52].ConclusionsIn this study, one-third of school children had inadequate energy consumption. Female headed households, being in the larger family size and housewives mother were significantly associated with inadequate energy consumption. Therefore, giving special focus to female headed households, large family and outdoor worker mothers will help to improve dietary intake of children.

The Development and Validation of Food Atlas for Portion Size Estimation in the Balkan Region.

Assessment of portion sizes is an important factor for the accuracy of food consumption surveys. The objective of this study was to develop and validate a food atlas of commonly consumed foods in the Balkan region in order to improve the accuracy of portion size estimation for food consumption surveys. A list of 135 foods and their portion sizes was based on previously conducted food consumption surveys in this region. Food was cooked, measured and served in three or four portion sizes right before being photographed. A validation study was conducted through the visual perception method. Without receiving training on usage of the food picture book, participants were asked to evaluate two portion sizes of 20 selected foods by comparison with a photo series of each food. Portion sizes were evaluated by 18 nutrition professionals and 17 lay individuals who had no nutritional education. Mean differences and the standard deviations of the mean differences (SD) between the portions estimated by each participant and the served portion were calculated. The percentages of participants who selected the correct, adjacent or distant portion size also were calculated. The number of food items that were quantified within the predefined acceptable range (i.e., mean difference < ∣ 0·7 ∣ and SD < 1) was 16 (80%) among lay individuals and 17 (85%) among nutritional professionals. Among 16 photo series that were assessed as “acceptable,” the percentage of all participants, who selected the correct picture, was between 44.3 and 82.9%, with an average of 60.2%. Only three foods were assessed correctly by <50% participants. The percentage of participants who selected the correct or adjacent serving size was above 98% for both lay and professional evaluators. This is the first food atlas containing representative foods and recipes commonly consumed in the Balkan region. However, further adjustments of the methodology should include larger number of food items to be tested, involvement of more participants and provision of training for the users of the food atlas. This food atlas could be used in food consumption surveys in the Balkan region after further testing and validation.

New approaches in assessing food intake in epidemiology.

A promising direction for improving dietary intake measurement in epidemiologic studies is the combination of short-term and long-term dietary assessment methods using statistical methods. Thereby, web-based instruments are particularly interesting as their application offers several potential advantages such as self-administration and a shorter completion time. The objective of this review is to provide an overview of new web-based short-term instruments and to describe their features. A number of web-based short-term dietary assessment tools for application in different countries and age-groups have been developed so far. Particular attention should be paid to the underlying database and the search function of the tool. Moreover, web-based instruments can improve the estimation of portion sizes by offering several options to the user. Web-based dietary assessment methods are associated with lower costs and reduced burden for participants and researchers, and show a comparable validity with traditional instruments. When there is a need for a web-based tool researcher should consider the adaptation of existing tools rather than developing new instruments. The combination of short-term and long-term instruments seems more feasible with the use of new technology.

Dietary Assessment with a Wearable Camera among Children: Feasibility and Intercoder Reliability

BackgroundThe eButton, a multisensor device worn on the chest, uses a camera to passively capture images of everything in front of the child throughout the day. These images can be analyzed to provide a passive method of dietary intake assessment. ObjectiveThis study assessed the eButton’s feasibility and intercoder reliability for dietary intake assessment. DesignChildren were recruited in the summer and fall of 2015, in Houston, TX, to wear the eButton to take 2 full days of dietary images, and the child–parent dyad participated in a following-day interview to verify what dietitians recorded from the images. Participants/settingThirty 9- to 13-year-old children participated during days convenient to them. Main outcome measuresTwo dietitians independently manually reviewed the images to identify eating events, foods in those events, and portion sizes. Statistical analyses performedDescriptive statistics of agreements and disagreements were calculated between dietitians and with children; t tests and Bland-Altman plots of differences in total kilocalories were calculated between dietitians and between initial dietitian estimates and those finalized after the verification interviews. ResultsThe dietitians agreed on the identity of 60.5% of the 1,026 foods but disagreed on 28.6% of the foods and on the names for 10.8% of the foods. After the verification interviews, the dietitians agreed with the child–parent dyads on the identity of 77.0% of the 921 foods; the child–parent dyad identified 12.4% of the day’s foods when images were not available or not clear; the child–parent dyad clarified that 5.4% of the foods identified were not consumed by the child; and the child–parent dyad clarified the identity of 5.2% of the foods. A software-based approach (three-dimensional wire mesh) could be used to estimate portion size on 24% of the foods, and professional judgment was required for 67.8%. Mean caloric intakes per day were not statistically significantly different between dietitians but were different between dietitians and child–parent dyads in total and on day 2. ConclusionsAn early test of intercoder reliability of an all-day image method of dietary intake assessment obtained intercoder agreement between the two dietitians processing these images of intraclass correlation coefficient=0.67. A following-day verification interview with the child and parent was necessary to ensure completeness of estimates. Several feasibility problems occurred, which may be remedied with additional participant and dietitian training and further technological development.

Narrative Review of New Methods for Assessing Food and Energy Intake.

Dietary self-report instruments are essential to nutritional analysis in dietetics practice and their use in research settings has facilitated numerous important discoveries related to nutrition, health and chronic diseases. An important example is obesity, for which measuring changes in energy intake is critical for assessing efficacy of dietary interventions. However, current methods, including counting calories, estimating portion size and using food labels to estimate human energy intake have considerable constraints; consequently, research on new methodologies/technologies has been encouraged to mitigate the present weaknesses. The use of technologies has prompted innovation in dietary analysis. In this review, the strengths and limitations of new approaches have been analyzed based on ease of use, practical limitations, and statistical evaluation of reliability and validity. Their utility is discussed through the lens of the 4Ms of Obesity Assessment and Management, which has been used to evaluate root causes of obesity and help select treatment options.

Accuracy of Parental Reporting of Preschoolers' Dietary Intake Using an Online Self-Administered 24-h Recall.

Parents are typically relied upon to report young children’s dietary intake. However, there has been limited research assessing the accuracy of such reports captured using novel dietary assessment tools. The purpose of the current study was to assess the validity of the web-based Automated Self-Administered 24-h Dietary Assessment Tool (ASA24-Canada) for capturing dietary intake among children aged two-five years (n = 40), using parental proxy reporting. The study was conducted in a daycare setting, allowing for standardization of foods and drinks offered and direct observation of intake. Parental-reported intake was compared to true intake for lunch and dinner, as well as an afternoon snack, on a single day. Each eating occasion, including plate waste, was unobtrusively documented. Parents were not present for lunch or the afternoon snack, but joined their children at the daycare centre for the dinner meal. The following day, parents reported their children’s intake from the previous 24-h period using ASA24-Canada. For the eating occasions assessed, parents reported exact or close matches for 79.2% (82.3% for lunch, 81.2% for the snack, and 77.4% for dinner) of the foods and beverages truly consumed by children. Estimates of intake for energy and macronutrients examined (carbohydrates, fat, and protein) based on parental reports were higher than those based on true (observed) intake. Our findings suggest that parents are able to report what their preschool children eat and drink relatively accurately. However, the accuracy of portion size estimates is low. Strategies to enhance portion size reporting are needed to improve parental proxy reporting.

Feasibility of Reviewing Digital Food Images for Dietary Assessment among Nutrition Professionals.

Validity of image-assisted and image-based dietary assessment methods relies on the accuracy of portion size estimation based on food images. However, little is known on the ability of nutrition professionals in assessing dietary intake based on digital food images. This study aims to examine the ability of nutrition professionals in reviewing food images with regard to food item identification and portion size estimation. Thirty-eight nutritionists, dietitians, and nutrition researchers participated in this study. Through an online questionnaire, participants’ accuracy in identifying food items and estimating portion sizes of two sets of digital food images presenting a meal on a plate (Image PL) and in a bowl (Image BW) were tested. Participants reported higher accuracy in interpreting Image BW compared to Image PL, both in terms of accuracy in food identification (75.3 ± 17.6 vs. 68.9 ± 17.1%) and percentage difference in portion size estimation (44.3 ± 16.6 vs. 47.6 ± 21.2%). Weight of raw vegetables was significantly underestimated (−45.1 ± 22.8% vs. −21.2 ± 37.4%), while drink was significantly overestimated (40.1 ± 45.8% vs. 26.1 ± 32.2) in both images. Less than one-third of the participants estimated portion size within 10% of actual weight for Image PL (23.7%) and Image BW (32.3%). Accuracy of nutrition professionals in reviewing food images could be further improved with training on better perception of portion sizes from images.

Equivalence-Based Instruction with Nonfood Items to Increase Portion-Size Estimation Accuracy

Stimulus equivalence paradigms are successful interventions for teaching individuals a variety of skills. In particular, researchers have taught individuals how to more accurately estimate portion sizes of foods using equivalence-based instruction (EBI). This area of research lacks information on the effects of using nonfood items during EBI. The purpose of the current study was to evaluate whether nonfood items could be used during training to increase portion-size estimation accuracy. Participants were three adult females. Preferred and nonpreferred foods were used to assess generalization of portion-size estimation accuracy. Foods were identified through an assessment and varied per participant. Two nonfood items were used for training and one novel nonfood item was to assess for generalization. Three classes of stimuli were taught using EBI (i.e., ¼ cup, ½ cup, and 1 cup). The members of each class were represented by portion-size measurement aids, amounts on paper plates, and measuring cups. All participants more accurately estimated each portion size of nonfood items after training sessions. Accurate estimation also generalized to preferred and nonpreferred foods, as well as a novel nonfood item, for all participants.

Feasibility of an estimated method using graduated utensils to estimate food portion size in infants aged 4 to 18 months.

The Diet and Nutrition Survey of Infants and Young Children (DNSIYC) was carried out in 2011 to assess the nutrient intakes of 4 to 18 month old infants in the UK. Prior to the main stage of DNSIYC, pilot work was undertaken to determine the impact of using graduated utensils to estimate portion sizes. The aims were to assess whether the provision of graduated utensils altered either the foods given to infants or the amount consumed by comparing estimated intakes to weighed intakes. Parents completed two 4-day food diaries over a two week period; an estimated diary using graduated utensils and a weighed diary. Two estimated diary formats were tested; half the participants completed estimated diaries in which they recorded the amount of food/drink served and the amount left over, and the other half recorded the amount of food/drink consumed only. Median daily food intake for the estimated and the weighed method were similar; 980g and 928g respectively. There was a small (6.6%) but statistically significant difference in energy intake reported by the estimated and the weighed method; 3189kJ and 2978kJ respectively. There were no statistically significant differences between estimated intakes from the served and left over diaries and weighed intakes (p>0.05). Estimated intakes from the amount consumed diaries were significantly different to weighed intakes (food weight (g) p = 0.02; energy (kJ) p = 0.01). There were no differences in intakes of amorphous (foods which take the shape of the container, e.g. pureed foods, porridge) and discrete food items (individual pieces of food e.g. biscuits, rice cakes) between the two methods. The results suggest that the household measures approach to reporting portion size, with the combined use of the graduated utensils, and recording the amount served and the amount left over in the food diaries, may provide a feasible alternative to weighed intakes.