Image-assisted dietary assessment: a systematic review of the evidence

Comparison of nutrient intakes in South Asians with type 2 diabetes mellitus and controls living in the United States

AIMS

Despite having a high risk for type 2 diabetes mellitus (T2DM), little is known about the relationship between nutrient intakes and T2DM in South Asians (SA) in the U.S. In addition, the available data are limited to a few macronutrients and collected using subjective measures. Therefore, we compared macro- and micro-nutrient intakes of SA migrants with and without T2DM using an objective measure.

METHODS

SA in the U.S. with T2DM (n = 44) and controls (n = 33) reported their dietary intake using image-assisted dietary assessment method. They took pictures of all foods/drinks consumed on two weekdays and one weekend day. Age, gender distribution, and body mass index were similar across the two groups.

RESULTS

SA with T2DM, as compared to controls, consumed less total energy (mean difference: 499 kcal/d; p < .0001), linoleic acid (3.6 g/d; p = .003), dietary fiber (8.6 g/d; p < .0001), vitamin A (262 µg/d; p = .003), vitamin E (2.7 mg/d; p = .007), calcium (133 mg/d; p = .01), magnesium (116 mg/d; p < .0001), zinc (1.4 mg/d; p = .004), potassium (754 mg/d; p < .0001), and β-carotene (1761 µg/d; p = .03). SA with T2DM, as compared to controls, were significantly more likely not to meet the requirements for linoleic acid, dietary fiber, vitamin E, calcium, magnesium, zinc, and potassium (p < .05).

CONCLUSIONS

SA with T2DM, compared to controls, consume less total energy and have lower consumption of many nutrients associated with reduced risk of T2DM. Dietary interventions to reduce risk for T2DM are warranted in SA.

Automatic food detection in egocentric images using artificial intelligence technology

OBJECTIVE

To develop an artificial intelligence (AI)-based algorithm which can automatically detect food items from images acquired by an egocentric wearable camera for dietary assessment.

DESIGN

To study human diet and lifestyle, large sets of egocentric images were acquired using a wearable device, called eButton, from free-living individuals. Three thousand nine hundred images containing real-world activities, which formed eButton data set 1, were manually selected from thirty subjects. eButton data set 2 contained 29 515 images acquired from a research participant in a week-long unrestricted recording. They included both food- and non-food-related real-life activities, such as dining at both home and restaurants, cooking, shopping, gardening, housekeeping chores, taking classes, gym exercise, etc. All images in these data sets were classified as food/non-food images based on their tags generated by a convolutional neural network.

RESULTS

A cross data-set test was conducted on eButton data set 1. The overall accuracy of food detection was 91·5 and 86·4 %, respectively, when one-half of data set 1 was used for training and the other half for testing. For eButton data set 2, 74·0 % sensitivity and 87·0 % specificity were obtained if both 'food' and 'drink' were considered as food images. Alternatively, if only 'food' items were considered, the sensitivity and specificity reached 85·0 and 85·8 %, respectively.

CONCLUSIONS

The AI technology can automatically detect foods from low-quality, wearable camera-acquired real-world egocentric images with reasonable accuracy, reducing both the burden of data processing and privacy concerns.

Global Dietary Surveillance: Data Gaps and Challenges

BACKGROUND

Detailed information on global individual-level consumption patterns is imperative for informed policy making. However, such data are dispersed and incomplete.

OBJECTIVE

To review and discuss the methodologies, observed data availability, challenges, and opportunities pertaining to global dietary surveillance.

METHODS

This investigation provides an extensive review of global dietary assessment methodologies and challenges, including at the survey level, the dietary collection and assessment level, and the dietary data processing and analysis level. The focus is on nationally representative individual-level data, and additional types of dietary data, such as dietary biomarkers, household assessment, and food availability, are reviewed as alternatives. Practical guidance is provided to inform key decisions when designing dietary surveys and collecting, analyzing, and using dietary data. This article further identifies and describes existing global and regional dietary initiatives/data sets.

RESULTS

Harmonized and standardized primary individual-level dietary data collection, processing, and analysis worldwide are currently not available. Evaluation and decision-making should be based on best available data, that is, secondary nonharmonized yet to the extent possible, standardized individual-level dietary data. Existing initiatives differ substantially in methodologies, including survey design/representativeness, coverage, diet assessment, and dietary metric standardization and processing. Data gaps have been identified that were more profound for certain countries, certain dietary indicators across countries, population subgroups, representativeness, or time periods.

CONCLUSIONS

Optimizing worldwide dietary habits to improve population health requires systematically identified and evaluated data on a continuing basis. Leveraging existing available dietary data and efforts is an indispensable prerequisite for informed priority setting targeting the intersections between diet and disease.

Utility of eButton images for identifying food preparation behaviors and meal-related tasks in adolescents

BACKGROUND

Food preparation skills may encourage healthy eating. Traditional assessment of child food preparation employs self- or parent proxy-reporting methods, which are prone to error. The eButton is a wearable all-day camera that has promise as an objective, passive method for measuring child food preparation practices.

PURPOSE

This paper explores the feasibility of the eButton to reliably capture home food preparation behaviors and practices in a sample of pre- and early adolescents (ages 9 to 13).

METHODS

This is a secondary analysis of two eButton pilot projects evaluating the dietary intake of pre- and early adolescents in or around Houston, Texas. Food preparation behaviors were coded into seven major categories including: browsing, altering food/adding seasoning, food media, meal related tasks, prep work, cooking and observing. Inter-coder reliability was measured using Cohen's kappa and percent agreement.

RESULTS

Analysis was completed on data for 31 participants. The most common activity was browsing in the pantry or fridge. Few participants demonstrated any food preparation work beyond unwrapping of food packages and combining two or more ingredients; actual cutting or measuring of foods were rare.

CONCLUSIONS

Although previous research suggests children who "help" prepare meals may obtain some dietary benefit, accurate assessment tools of food preparation behavior are lacking. The eButton offers a feasible approach to food preparation behavior measurement among pre- and early adolescents. Follow up research exploring the validity of this method in a larger sample, and comparisons between cooking behavior and dietary intake are needed.

Research into food portion size: methodological aspects and applications

Portion sizes for certain foods have been increasing dramatically in recent years alongside obesity rates, concurring with the phenomenon of the portion size effect (more is consumed when more is offered). Portion size may be defined based on different purposes such as for dietary assessment, or therapeutic advice or food labelling, resulting in a variety of measurement methods and specifications. This situation has resulted in disagreements on establishing portion size recommendations by manufacturers, food distributors, restaurants, health professionals and policy makers, contributing to confusion amongst consumers on the amounts of food to be consumed, and potentially increasing the likelihood of overeating and other obesity-related behaviours. Such variability is also reflected in the research field making comparison across studies on portion size difficult. The aim of this review is to provide an overview of definitions and methods used in research to evaluate portion-size related outcomes, including methods to estimate amounts consumed by individuals as part of dietary assessment; methods to analyse cognitive mechanisms related to portion size behaviour; and methods to evaluate the impact of portion size manipulations as well as individual plus environmental factors on portion size behaviour. Special attention has been paid to behavioural studies exploring portion size cognitive processes given the lack of previous methodological reviews in this area. This information may help researchers, clinicians and other stakeholders to establish clearer definitions of portion size in their respective areas of work and to standardise methods to analyse portion size effects.

Comparison of self-reported dietary intakes from the Automated Self-Administered 24-h recall, 4-d food records, and food-frequency questionnaires against recovery biomarkers

Background

A limited number of studies have evaluated self-reported dietary intakes against objective recovery biomarkers.

Objective

The aim was to compare dietary intakes of multiple Automated Self-Administered 24-h recalls (ASA24s), 4-d food records (4DFRs), and food-frequency questionnaires (FFQs) against recovery biomarkers and to estimate the prevalence of under- and overreporting.

Design

Over 12 mo, 530 men and 545 women, aged 50-74 y, were asked to complete 6 ASA24s (2011 version), 2 unweighed 4DFRs, 2 FFQs, two 24-h urine collections (biomarkers for protein, potassium, and sodium intakes), and 1 administration of doubly labeled water (biomarker for energy intake). Absolute and density-based energy-adjusted nutrient intakes were calculated. The prevalence of under- and overreporting of self-report against biomarkers was estimated.

Results

Ninety-two percent of men and 87% of women completed ≥3 ASA24s (mean ASA24s completed: 5.4 and 5.1 for men and women, respectively). Absolute intakes of energy, protein, potassium, and sodium assessed by all self-reported instruments were systematically lower than those from recovery biomarkers, with underreporting greater for energy than for other nutrients. On average, compared with the energy biomarker, intake was underestimated by 15-17% on ASA24s, 18-21% on 4DFRs, and 29-34% on FFQs. Underreporting was more prevalent on FFQs than on ASA24s and 4DFRs and among obese individuals. Mean protein and sodium densities on ASA24s, 4DFRs, and FFQs were similar to biomarker values, but potassium density on FFQs was 26-40% higher, leading to a substantial increase in the prevalence of overreporting compared with absolute potassium intake.

Conclusions

Although misreporting is present in all self-report dietary assessment tools, multiple ASA24s and a 4DFR provided the best estimates of absolute dietary intakes for these few nutrients and outperformed FFQs. Energy adjustment improved estimates from FFQs for protein and sodium but not for potassium. The ASA24, which now can be used to collect both recalls and records, is a feasible means to collect dietary data for nutrition research.

Evaluation of Dietary Intakes and Nutritional Knowledge in Thai Patients with Type 2 Diabetes Mellitus

INTRODUCTION

Most nutritional guidelines for diabetes management emphasize the importance of having individualized goals, away from a one-size-fits-all approach. However, there is a dearth of information on the dietary intakes and nutritional knowledge of Thai patients with type 2 diabetes mellitus (T2DM). This study is aimed at clarifying dietary intakes in relationship to glycemic control and at examining nutritional knowledge among Thai patients with T2DM.

MATERIALS AND METHODS

A cross-sectional study of outpatients with T2DM at Theptarin Hospital and Ramathibodi Hospital (Bangkok, Thailand) was performed to assess dietary intakes by food records. Diabetes nutritional knowledge and dietary self-care behavior was also evaluated.

RESULTS

A total of 304 Thai patients with T2DM (female 52.6%, mean age 57.4 ± 10.9 years, body mass index (BMI) 27.3 ± 4.8 kg/m², and baseline A1C 7.2 ± 1.3%) participated in the study. The mean daily calorie intake was 1427 ± 425 kcal, and mean intake for each macronutrient was acceptable (carbohydrate 52%, protein 17%, and fat 31%). However, the intake of free sugar was much higher (12.1 ± 5.8% of total daily energy intake) and dietary fiber intake (9 grams per day) was much lower than recommended. There were no correlations between dietary intake and glycemic control. A subset of patients (N = 213) completed the diabetes nutritional knowledge survey. There was no association between diabetes nutritional knowledge and the actual dietary self-care behavior.

CONCLUSION

These results indicate that compliance of Thai patients with T2DM to dietary recommendations is not completely satisfactory, especially for free sugar and dietary fiber intakes. Addressing the reality of how patients with T2DM eat in their daily lives and their knowledge gaps would enable them to adhere to medical nutrition therapy.

The validity of dietary assessment methods to accurately measure energy intake in children and adolescents who are overweight or obese: a systematic review

The accurate assessment of energy intake in children and adolescents is an important outcome measure for clinical and population-based research. This systematic review aimed to determine the validity of dietary assessment methods to measure energy intake in children and adolescents who are classified as overweight or obese by comparison with doubly labelled water. Five electronic databases were searched using keywords. Of the 5263 papers identified, seven papers describing six studies met the inclusion criteria. Studies were included in the review if participants were classified as overweight or obese, aged 0-18 years old, if they estimated energy intake via a dietary assessment method and if they compared this to total energy expenditure measured via the doubly labelled water method. All studies were cross-sectional in nature, and each used one dietary assessment method, including 14-day-food record (FR; n = 1), 24 h dietary recall (n = 1), 8-day FR (n = 1), 9-day FR (n = 1), 3-day FR (n = 1) and diet history interview (n = 1). Sample sizes ranged from 9 to 59 participants, with the majority of studies including less than 30 participants (n = 4). Mis-reporting was evident in all of the studies, with under-reporting (n = 5) more frequent than over-reporting (n = 1). Findings from this review suggest that a 24-h dietary recall and diet history interview were the most accurate methods at the group level for children aged 4-14 years, where the parent or combined child and parent were the reporters.

Validity of Dietary Assessment in Athletes: A Systematic Review

Dietary assessment methods that are recognized as appropriate for the general population are usually applied in a similar manner to athletes, despite the knowledge that sport-specific factors can complicate assessment and impact accuracy in unique ways. As dietary assessment methods are used extensively within the field of sports nutrition, there is concern the validity of methodologies have not undergone more rigorous evaluation in this unique population sub-group. The purpose of this systematic review was to compare two or more methods of dietary assessment, including dietary intake measured against biomarkers or reference measures of energy expenditure, in athletes. Six electronic databases were searched for English-language, full-text articles published from January 1980 until June 2016. The search strategy combined the following keywords: diet, nutrition assessment, athlete, and validity; where the following outcomes are reported but not limited to: energy intake, macro and/or micronutrient intake, food intake, nutritional adequacy, diet quality, or nutritional status. Meta-analysis was performed on studies with sufficient methodological similarity, with between-group standardized mean differences (or effect size) and 95% confidence intervals (CI) being calculated. Of the 1624 studies identified, 18 were eligible for inclusion. Studies comparing self-reported energy intake (EI) to energy expenditure assessed via doubly labelled water were grouped for comparison (n = 11) and demonstrated mean EI was under-estimated by 19% (-2793 ± 1134 kJ/day). Meta-analysis revealed a large pooled effect size of -1.006 (95% CI: -1.3 to -0.7; p < 0.001). The remaining studies (n = 7) compared a new dietary tool or instrument to a reference method(s) (e.g., food record, 24-h dietary recall, biomarker) as part of a validation study. This systematic review revealed there are limited robust studies evaluating dietary assessment methods in athletes. Existing literature demonstrates the substantial variability between methods, with under- and misreporting of intake being frequently observed. There is a clear need for careful validation of dietary assessment methods, including emerging technical innovations, among athlete populations.

Scaling up Dietary Data for Decision-Making in Low-Income Countries: New Technological Frontiers

Dietary surveys in low-income countries (LICs) are hindered by low investment in the necessary research infrastructure, including a lack of basic technology for data collection, links to food composition information, and data processing. The result has been a dearth of dietary data in many LICs because of the high cost and time burden associated with dietary surveys, which are typically carried out by interviewers using pencil and paper. This study reviewed innovative dietary assessment technologies and gauged their suitability to improve the quality and time required to collect dietary data in LICs. Predefined search terms were used to identify technologies from peer-reviewed and gray literature. A total of 78 technologies were identified and grouped into 6 categories: 1) computer- and tablet-based, 2) mobile-based, 3) camera-enabled, 4) scale-based, 5) wearable, and 6) handheld spectrometers. For each technology, information was extracted on a number of overarching factors, including the primary purpose, mode of administration, and data processing capabilities. Each technology was then assessed against predetermined criteria, including requirements for respondent literacy, battery life, requirements for connectivity, ability to measure macro- and micronutrients, and overall appropriateness for use in LICs. Few technologies reviewed met all the criteria, exhibiting both practical constraints and a lack of demonstrated feasibility for use in LICs, particularly for large-scale, population-based surveys. To increase collection of dietary data in LICs, development of a contextually adaptable, interviewer-administered dietary assessment platform is recommended. Additional investments in the research infrastructure are equally important to ensure time and cost savings for the user.

Validation of the Online version of the Previous Day Food Questionnaire for schoolchildren

ABSTRACT Objective To evaluate the validity of the web-based version of the Previous Day Food Questionnaire Online for schoolchildren from the 2nd to 5th grades of elementary school. Methods Participants were 312 schoolchildren aged 7 to 12 years of a public school from the city of Florianópolis, Santa Catarina, Brazil. Validity was assessed by sensitivity, specificity, as well as by agreement rates (match, omission, and intrusion rates) of food items reported by children on the Previous Day Food Questionnaire Online, using direct observation of foods/beverages eaten during school meals (mid-morning snack or afternoon snack) on the previous day as the reference. Multivariate multinomial logistic regression analysis was used to evaluate the influence of participants’ characteristics on omission and intrusion rates. Results The results showed adequate sensitivity (67.7%) and specificity (95.2%). There were low omission and intrusion rates of 22.8% and 29.5%, respectively when all food items were analyzed. Pizza/hamburger showed the highest omission rate, whereas milk and milk products showed the highest intrusion rate. The participants who attended school in the afternoon shift presented a higher probability of intrusion compared to their peers who attended school in the morning. Conclusion The Previous Day Food Questionnaire Online possessed satisfactory validity for the assessment of food intake at the group level in schoolchildren from the 2nd to 5th grades of public school.

Technology Interventions to Manage Food Intake: Where Are We Now?

PURPOSE OF REVIEW

This review describes the state-of-the-art for dietary assessment using smartphone apps and digital technology and provides an update on the efficacy of technology-mediated interventions for dietary change.

RECENT FINDINGS

Technology has progressed from apps requiring entry of foods consumed, to digital imaging to provide food intake data. However, these methods rely on patients being active in data collection. The automated estimation of the volume and composition of every meal consumed globally is years away. The use of text messaging, apps, social media, and combinations of these for interventions is growing and proving effective for type 2 diabetes mellitus (T2DM). Effectiveness of text messaging for obesity management is improving and multicomponent interventions show promise. A stand-alone app is less likely to produce positive outcomes and social media is relatively unexplored. A concentrated effort will be needed to progress digital dietary assessment. Researcher-designed technology programs are producing positive outcomes for T2DM but further research is needed in the area of weight management.

Validity of the Remote Food Photography Method Against Doubly Labeled Water Among Minority Preschoolers

OBJECTIVE

The aim of this study was to determine the validity of energy intake (EI) estimations made using the remote food photography method (RFPM) compared to the doubly labeled water (DLW) method in minority preschool children in a free-living environment.

METHODS

Seven days of food intake and spot urine samples excluding first void collections for DLW analysis were obtained on thirty-nine 3- to 5-year-old Hispanic and African American children. Using an iPhone, caregivers captured before and after pictures of each child's intake, pictures were wirelessly transmitted to trained raters who estimated portion size using existing visual estimation procedures, and energy and macronutrients were calculated. Paired t tests, mean differences, and Bland-Altman limits of agreement were performed.

RESULTS

The mean EI was 1,191 ± 256 kcal/d using the RFPM and 1,412 ± 220 kcal/d using the DLW method, resulting in a mean underestimate of 222 kcal/d (-15.6%; P < 0.0001) that was consistent regardless of intake. The RFPM underestimated EI by -28.5% in 34 children and overestimated EI by 15.6% in 5 children.

CONCLUSIONS

The RFPM underestimated total EI when compared to the DLW method among preschoolers. Further refinement of the RFPM is needed for assessing the EI of young children.

Electronic-based lifestyle interventions in overweight or obese perinatal women: a systematic review and meta-analysis

Electronic-based (e-based) lifestyle interventions provide potential and cost-effective delivery of remote interventions for overweight and obese perinatal women. To date, no meta-analysis has reported the efficacy of maternal and neonatal outcomes. Seven electronic databases were searched from inception up to July 13, 2016, including the Cumulative Index to Nursing and Allied Health Literature, Cochrane Library, EMBASE, ProQuest Dissertations and Theses, PsycINFO, PubMed and Scopus. Among the 1,145 studies retrieved, 14 randomized controlled trials were selected among 17 publications. The Cochrane risk of bias tool was used to appraise the quality assessment. The meta-analyses demonstrated a significant result for limiting gestational weight gain, losing postnatal weight in 1-2 months, increasing self-reported moderate and vigorous physical activity and reducing caloric intake using diet-related software. Our review shows that an e-based lifestyle intervention is an acceptable approach. The findings reveal the variability in intervention methods and provide limited conclusive evidence. Thus, future studies should examine the efficacy and essential components as well as the various approaches using optimal portions of in-person and phone sessions. Further evaluations comparing the effectiveness of different e-based lifestyle intervention approaches toward activity-related and diet-related outcomes are necessary.

Do Image-Assisted Mobile Applications Improve Dietary Habits, Knowledge, and Behaviours in Elite Athletes? A Pilot Study

To date, there has been a paucity of research on optimal ways to educate and promote dietary behavioural change within athletes. Optimising athlete nutrition is fundamental to reaching peak performance and maintaining athlete wellbeing. MealLogger^® is a smartphone application that incorporates the use of an image-based food record and social-media functionality to provide in-application personalised feedback to individuals or groups, peer-support, and a platform to deliver nutrition education material. This study measured the feasibility of MealLogger^® within New Zealand elite male field hockey players (n = 17) aged 18–20 to increase athlete knowledge and nutrition promoting behaviours. During a six-week intervention, participants were instructed to log images of their meals three days per week and they received individualised dietetic feedback on logged meals. Weekly nutrition-education fact-sheets and videos were delivered through the application. Nutrition knowledge increased moderately from baseline (%Pre 54.7 ± 14.3; %Post 61.1 ± 11.45, p = 0.01). Participants report a highly positive experience of application use (8/10) with 82.3% attempting to make positive changes in dietary behaviours based on in-app education. All participants preferred this method to traditional methods of dietary analysis. Using image-based applications such as MealLogger^® is an effective approach to monitor dietary intake and deliver education to optimise the nutritional behaviours of elite athletes.

Measuring diet in the 21st century: use of new technologies

The advent of the internet and smartphone technology has allowed dietary assessment to reach the 21st century! The variety of foods available on the supermarket shelf is now greater than ever before. New approaches to measuring diet may help to reduce measurement error and advance our understanding of nutritional determinants of disease. This advance provides the potential to capture detailed dietary data on large numbers of individuals without the need for costly and time-consuming manual nutrition coding. This aim of the present paper is to review the need for new technologies to measure diet with an overview of tools available. The three main areas will be addressed: (1) development of web-based tools to measure diet; (2) use of smartphone apps to self-monitor diet; (3) improving the quality of dietary assessment through development of an online library of tools. A practical example of the development of a web-based tool to assess diet myfood24 (www.myfood24.org) will be given exploring its potential, limitations and challenges. The development of a new food composition database using back-of-pack information will be described. Smartphone apps used to measure diet with a focus on obesity will be reviewed. Many apps are unreliable in terms of tracking, and most are not evaluated. Accurate and consistent measurement of diet is needed for public health and epidemiology. The choice of the most appropriate dietary assessment method tends to rely on experience. The DIET@NET partnership has developed best practice guidelines for selection of dietary assessment tools, which aim to improve the quality, consistency and comparability of dietary data. These developments provide us with a step-change in our ability to reliably characterise food and nutrient intake in population studies. The need for high-quality, validated systems will be important to fully realise the benefits of new technologies.

Use of a Mobile Application for Self-Monitoring Dietary Intake: Feasibility Test and an Intervention Study

Given the increasing social and economic burden of chronic disease and the need for efficient approaches to prevent and treat chronic disease, emphasis on the use of information and communication technology (ICT)-based health care has emerged. We aimed to test the feasibility of a mobile application, Diet-A, and examine whether Diet-A could be used to monitor dietary intake among adolescents. In a three-month pre–post intervention study, 9 male and 24 female high school students aged 16–18 years consented and participated in this study. Participants were instructed to record all foods and beverages consumed using voice or text mode input. Nutrient intake was measured using 24-h recalls pre- and post-intervention. We compared nutrient intake data assessed by Diet-A application with those assessed by 24-h recalls. Participants tended to underreport intakes of nutrients compared to those assessed by two 24-h recalls. There were significant decreases in sodium (p = 0.04) and calcium (p = 0.03) intake between pre- and post-intervention. Of participants who completed questionnaires of feasibility (n = 24), 61.9% reported that they were satisfied using the application to monitor their food intake, and 47.7% liked getting personal information about their dietary intake from the application. However, more than 70% of participants answered that it was burdensome to use the application or that they had trouble remembering to record their food intake. The mobile application Diet-A offers the opportunity to monitor dietary intake through real-time feedback. However, use of Diet-A may not provide accurate information on the food intake of adolescents, partly because of the recording burden.

Snap-N-Send: A valid and reliable method for assessing the energy intake of elite adolescent athletes

To ensure that elite adolescent athletes meet their unique training, growth and maturation demands, it is imperative to have access to valid measures of energy intake. Contemporary methods demand close attention-to-detail, meaning that athletes often do not fully adhere to real-time protocols. This study represents the first investigation of a real-time dietary assessment designed using a comprehensive behaviour change framework (COM-B). In a crossover design, 12 elite adolescent male rugby players recorded their energy intake via an estimated food diary (est-FD) and photography-based mobile assessment ('Snap-n-Send'), combined with a 24-h dietary recall interview. Two 4-day assessment periods were divided into three separate recording environments: 96 h free-living and researcher-observed; 72 h free-living and 10 h researcher-observed. Assessment periods were one month apart. All foods and beverages were provided and weighed by the research team to quantify actual intakes. 'Snap-n-Send' reported a small mean bias for under-reporting across 96 h (-0.75 MJ day^-1; 95% confidence interval [CI] for bias = -5.7% to -2.2%, p < .001), 72 h (-0.76 MJ day^-1; 95% CI for bias = -5.6% to -2.1%, p = .004) and 10 h (-0.72 MJ day^-1; 95% CI for bias = -8.1% to -0.1%; p = .067) environments. The est-FD reported a moderate mean bias for under-reporting across 96 h (-2.89 MJ day^-1; 95% CI for bias = -17.9% to -10.2%; p < .001), 72 h (-2.88 MJ day^-1; 95% CI for bias = -17.9% to -10.1%; p < .001) and 10 h (-2.52 MJ day^-1;-26.1% to -5.3%; p = .023) environments. Results evidence the ability of 'Snap-n-Send' to accurately assess the diet of elite adolescent athletes, signalling the exciting promise of this comprehensive and theoretical behavioural approach within valid dietary assessment.

Validation of energy intake from a web-based food recall for children and adolescents

The purpose of this study was to validate estimated energy intake from a web-based food recall, designed for children and adolescents. We directly compared energy intake to estimates of total energy expenditure, calculated from accelerometer outputs, combined with data on weight and sex or resting energy expenditure prediction equations. Children (8–9 years) and adolescents (12–14 years) were recruited through schools in Norway in 2013 (N = 253). Results showed that more than one third (36–37%) were identified as under-reporters of energy. In contrast, only 2–4% were defined as over-reporters of energy. The mean energy intake was under-reported with -1.83 MJ/day for the entire study sample. Increased underestimation was observed for overweight and obese participants, the oldest age group (12–14 years), boys, those with parents/legal guardians with low educational level and those living in non-traditional families. In conclusion, energy intake from the web-based food recall is significantly underestimated compared with total energy expenditure, and should be used with caution in young people.

Designing Health Apps to Support Dietetic Professional Practice and Their Patients: Qualitative Results From an International Survey

Background

Dietitians are engaging with mobile health (mHealth) technologies, particularly with diet and nutrition apps in their patient care. Despite the plethora of apps available, the majority are not designed with a dietitian’s input.

Objective

The aim of this study was to identify the user preferences of dietitians in relation to tools, resources, and design features for smartphone health apps that would support their dietetic professional practice and their patients.

Methods

As part of a larger international Web-based survey of health-app use among dietitians, three open-ended responses were included for specific exploration of app design features and additional resources or tools that could guide the development of apps for use in dietetic practice and patient care. Inductive thematic analysis of responses was conducted using the qualitative data analysis program, NVivo version 11 (QSR International Pty Ltd), to understand the design preferences and features valued by dietitians.

Results

The responses from 381 dietitian respondents were analyzed. Five key themes were identified. Dietitians wanted access to credible apps, suggesting that dietetic associations should have greater involvement in reviewing and endorsing evidence-based apps for use in dietary counseling. Improvements to the usability of apps, relating to their ease of use and design, were also raised, as self-monitoring of dietary behaviors using existing nutrition apps was deemed to be burdensome. Furthermore, apps providing dietitian-oriented support were favored, for example, those with the ability to streamline the dietary assessment process, so that dietitians could spend more time on dietary counseling and negotiating patient goals for dietary and lifestyle behavior change. Provision of patient-oriented support, such as functionality to tailor apps to patient-specific needs, was also considered important. Finally, respondents valued apps that could integrate into their work systems to enhance the quality of the dietitian-patient relationship.

Conclusions

App developers should draw upon the features and characteristics valued by dietitians to guide their development of apps that support dietetic practice and enhance patient care. Moreover, to achieve better dietitian and patient-centered app design, it is imperative that app developers take a collaborative approach with dietitians, their professional associations, and their patients.

Reported Energy Intake Accuracy Compared to Doubly Labeled Water and Usability of the Mobile Food Record among Community Dwelling Adults

The mobile Food Record (mFR) is an image-based dietary assessment method for mobile devices. The study primary aim was to test the accuracy of the mFR by comparing reported energy intake (rEI) to total energy expenditure (TEE) using the doubly labeled water (DLW) method. Usability of the mFR was assessed by questionnaires before and after the study. Participants were 45 community dwelling men and women, 21-65 years. They were provided pack-out meals and snacks and encouraged to supplement with usual foods and beverages not provided. After being dosed with DLW, participants were instructed to record all eating occasions over a 7.5 days period using the mFR. Three trained analysts estimated rEI from the images sent to a secure server. rEI and TEE correlated significantly (Spearman correlation coefficient of 0.58, p < 0.0001). The mean percentage of underreporting below the lower 95% confidence interval of the ratio of rEI to TEE was 12% for men (standard deviation (SD) ± 11%) and 10% for women (SD ± 10%). The results demonstrate the accuracy of the mFR is comparable to traditional dietary records and other image-based methods. No systematic biases could be found. The mFR was received well by the participants and usability was rated as easy.

A Systematic Review of Technology-Based Dietary Intake Assessment Validation Studies That Include Carotenoid Biomarkers

Technological advances have allowed for the evolution of traditional dietary assessment methods. The aim of this review is to evaluate the accuracy of technology-based dietary assessment methods to determine carotenoid and/or fruit and vegetable intake when compared with carotenoid biomarkers. An online search strategy was undertaken to identify studies published in the English language up to July 2016. Inclusion criteria were adults ≥18 years, a measure of dietary intake that used information and communication technologies that specified fruit and/or vegetable intake or dietary carotenoid, a biomarker of carotenoid status and the association between the two. Sixteen articles from 13 studies were included with the majority cross-sectional in design (n = 9). Some studies used multiple dietary assessment methods with the most common: food records (n = 7), 24-h diet recalls (n = 5), food frequency questionnaires (n = 3) and diet quality assessed by dietary screener (n = 1). Two studies were directly web based, with four studies using technology that could be completed offline and data later transferred. Two studies utilised technology in the collection of dietary data, while the majority (n = 11) automated the collection in combination with nutrient analysis of the dietary data. Four studies provided correlation values between dietary carotenoids with biomarkers, ranging from r = 0.13 to 0.62 with the remaining studies comparing a measure of fruit and vegetable intake with biomarkers (r = 0.09 to 0.25). This review provides an overview of technology-based dietary assessment methods that have been used in validation studies with objectively measured carotenoids. Findings were positive with these dietary assessment measures showing mostly moderate associations with carotenoid biomarkers.

Image-Based Dietary Assessment Ability of Dietetics Students and Interns

Image-based dietary assessment (IBDA) may improve the accuracy of dietary assessments, but no formalized training currently exists for skills relating to IBDA. This study investigated nutrition and dietetics students' and interns' IBDA abilities, the training and experience factors that may contribute to food identification and quantification accuracy, and the perceived challenges to performing IBDA. An online survey containing images of known foods and serving sizes representing common American foods was used to assess the ability to identify foods and serving sizes. Nutrition and dietetics students and interns from the United States and Australia (n = 114) accurately identified foods 79.5% of the time. Quantification accuracy was lower, with only 38% of estimates within ±10% of the actual weight. Foods of amorphous shape or higher energy density had the highest percent error. Students expressed general difficulty with perceiving serving sizes, making IBDA food quantification more difficult. Experience cooking at home from a recipe, frequent measuring of portions, and having a food preparation or cooking laboratory class were associated with enhanced accuracy in IBDA. Future training of dietetics students should incorporate more food-based serving size training to improve quantification accuracy while performing IBDA, while advances in IBDA technology are also needed.

Innovative approaches to estimate individual usual dietary intake in large-scale epidemiological studies

Valid estimation of usual dietary intake in epidemiological studies is a topic of present interest. The aim of the present paper is to review recent literature on innovative approaches focussing on: (1) the requirements to assess usual intake and (2) the application in large-scale settings. Recently, a number of technology-based self-administered tools have been developed, including short-term instruments such as web-based 24-h recalls, mobile food records or simple closed-ended questionnaires that assess the food intake of the previous 24 h. Due to their advantages in terms of feasibility and cost-effectiveness these tools may be superior to conventional assessment methods in large-scale settings. New statistical methods have been developed to combine dietary information from repeated 24-h dietary recalls and FFQ. Conceptually, these statistical methods presume that the usual food intake of a subject equals the probability of consuming a food on a given day, multiplied by the average amount of intake of that food on a typical consumption day. Repeated 24-h recalls from the same individual provide information on consumption probability and amount. In addition, the FFQ can add information on intake frequency of rarely consumed foods. It has been suggested that this combined approach may provide high-quality dietary information. A promising direction for estimation of usual intake in large-scale settings is the integration of both statistical methods and new technologies. Studies are warranted to assess the validity of estimated usual intake in comparison with biomarkers.

Characterizing Early Adolescent Plate Waste Using the Mobile Food Record

This study aimed to assess the amount of plate waste and how plate waste was disposed by early adolescent girls using a mobile food record (mFR). Participants were girls nine to thirteen years residing in O’ahu, Hawai’i (n = 93). Foods selected and leftover were estimated using a three day mFR. Each leftover food was then classified as thrown into the trash, fed to a pet, eaten later, or other (e.g., composted). Repeated measures analyses of variance (ANOVA) were conducted and Tukey’s post-hoc test were used to adjust for multiple comparisons between times (breakfast, lunch, dinner, and snack) on leftover food and leftover food thrown into the trash. The percentage of food leftover and thrown into the trash was highest at lunch. The percentage of protein, grain, vegetables, fruit, and dairy leftover at lunch were unexpectedly low compared to previous studies. The median for percentage of food thrown into the trash at lunch was <5% for all food groups, and was consistently low across the day (<10%). Average energy intake was 436 kcal (±216) at lunch, and 80% of caregivers reported total household income as ≥$70,000. Studies in real-time using technology over full days may better quantify plate waste among adolescents.

Unobtrusive and Wearable Systems for Automatic Dietary Monitoring

The threat of obesity, diabetes, anorexia, and bulimia in our society today has motivated extensive research on dietary monitoring. Standard self-report methods such as 24-h recall and food frequency questionnaires are expensive, burdensome, and unreliable to handle the growing health crisis. Long-term activity monitoring in daily living is a promising approach to provide individuals with quantitative feedback that can encourage healthier habits. Although several studies have attempted automating dietary monitoring using wearable, handheld, smart-object, and environmental systems, it remains an open research problem. This paper aims to provide a comprehensive review of wearable and hand-held approaches from 2004 to 2016. Emphasis is placed on sensor types used, signal analysis and machine learning methods, as well as a benchmark of state-of-the art work in this field. Key issues, challenges, and gaps are highlighted to motivate future work toward development of effective, reliable, and robust dietary monitoring systems.

A review of the design and validation of web- and computer-based 24-h dietary recall tools

Technology-based dietary assessment offers solutions to many of the limitations of traditional dietary assessment methodologies including cost, participation rates and the accuracy of data collected. The 24-h dietary recall (24HDR) method is currently the most utilised method for the collection of dietary intake data at a national level. Recently there have been many developments using web-based platforms to collect food intake data using the principles of the 24HDR method. This review identifies web- and computer-based 24HDR tools that have been developed for both children and adult population groups, and examines common design features and the methods used to investigate the performance and validity of these tools. Overall, there is generally good to strong agreement between web-based 24HDR and respective reference measures for intakes of macro- and micronutrients.

New mobile methods for dietary assessment: review of image-assisted and image-based dietary assessment methods

For nutrition practitioners and researchers, assessing dietary intake of children and adults with a high level of accuracy continues to be a challenge. Developments in mobile technologies have created a role for images in the assessment of dietary intake. The objective of this review was to examine peer-reviewed published papers covering development, evaluation and/or validation of image-assisted or image-based dietary assessment methods from December 2013 to January 2016. Images taken with handheld devices or wearable cameras have been used to assist traditional dietary assessment methods for portion size estimations made by dietitians (image-assisted methods). Image-assisted approaches can supplement either dietary records or 24-h dietary recalls. In recent years, image-based approaches integrating application technology for mobile devices have been developed (image-based methods). Image-based approaches aim at capturing all eating occasions by images as the primary record of dietary intake, and therefore follow the methodology of food records. The present paper reviews several image-assisted and image-based methods, their benefits and challenges; followed by details on an image-based mobile food record. Mobile technology offers a wide range of feasible options for dietary assessment, which are easier to incorporate into daily routines. The presented studies illustrate that image-assisted methods can improve the accuracy of conventional dietary assessment methods by adding eating occasion detail via pictures captured by an individual (dynamic images). All of the studies reduced underreporting with the help of images compared with results with traditional assessment methods. Studies with larger sample sizes are needed to better delineate attributes with regards to age of user, degree of error and cost.

A Brief Tool to Assess Image-Based Dietary Records and Guide Nutrition Counselling Among Pregnant Women: An Evaluation

Background

Dietitians ideally should provide personally tailored nutrition advice to pregnant women. Provision is hampered by a lack of appropriate tools for nutrition assessment and counselling in practice settings. Smartphone technology, through the use of image-based dietary records, can address limitations of traditional methods of recording dietary intake. Feedback on these records can then be provided by the dietitian via smartphone. Efficacy and validity of these methods requires examination.

Objective

The aims of the Australian Diet Bytes and Baby Bumps study, which used image-based dietary records and a purpose-built brief Selected Nutrient and Diet Quality (SNaQ) tool to provide tailored nutrition advice to pregnant women, were to assess relative validity of the SNaQ tool for analyzing dietary intake compared with nutrient analysis software, to describe the nutritional intake adequacy of pregnant participants, and to assess acceptability of dietary feedback via smartphone.

Methods

Eligible women used a smartphone app to record everything they consumed over 3 nonconsecutive days. Records consisted of an image of the food or drink item placed next to a fiducial marker, with a voice or text description, or both, providing additional detail. We used the SNaQ tool to analyze participants’ intake of daily food group servings and selected key micronutrients for pregnancy relative to Australian guideline recommendations. A visual reference guide consisting of images of foods and drinks in standard serving sizes assisted the dietitian with quantification. Feedback on participants’ diets was provided via 2 methods: (1) a short video summary sent to participants’ smartphones, and (2) a follow-up telephone consultation with a dietitian. Agreement between dietary intake assessment using the SNaQ tool and nutrient analysis software was evaluated using Spearman rank correlation and Cohen kappa.

Results

We enrolled 27 women (median age 28.8 years, 8 Indigenous Australians, 15 primiparas), of whom 25 completed the image-based dietary record. Median intakes of grains, vegetables, fruit, meat, and dairy were below recommendations. Median (interquartile range) intake of energy-dense, nutrient-poor foods was 3.5 (2.4-3.9) servings/day and exceeded recommendations (0-2.5 servings/day). Positive correlations between the SNaQ tool and nutrient analysis software were observed for energy (ρ=.898, P<.001) and all selected micronutrients (iron, calcium, zinc, folate, and iodine, ρ range .510-.955, all P<.05), both with and without vitamin and mineral supplements included in the analysis. Cohen kappa showed moderate to substantial agreement for selected micronutrients when supplements were included (kappa range .488-.803, all P ≤.001) and for calcium, iodine, and zinc when excluded (kappa range .554-.632, all P<.001). A total of 17 women reported changing their diet as a result of the personalized nutrition advice.

Conclusions

The SNaQ tool demonstrated acceptable validity for assessing adequacy of key pregnancy nutrient intakes and preliminary evidence of utility to support dietitians in providing women with personalized advice to optimize nutrition during pregnancy.

The Use of Digital Images in 24-Hour Recalls May Lead to Less Misestimation of Portion Size Compared with Traditional Interviewer-Administered Recalls

BACKGROUND

The Automated Self-Administered 24-hour (ASA24) dietary recall system enhances the feasibility of collecting high-quality intake data in population-based studies.

OBJECTIVE

The aim of this study was to assess the accuracy of portion size reporting in the ASA24 compared with interviewer-administered recalls.

METHODS

True intake for 3 meals was ascertained in 81 adults aged 20-70 y from the Washington, DC area. Participants were randomly assigned to complete an unannounced ASA24 or an interviewer-administered Automated Multiple-Pass Method (AMPM) recall the following day. An adapted Bland-Altman approach was used to assess agreement between true and reported portion sizes. Linear regression was used to assess log-scale differences between true and reported portion sizes by recall mode. The proportions of reported portion sizes within 10% and 25% of truth were estimated. Analyses were conducted for all foods and drinks and predetermined categories.

RESULTS

Mean differences between true and reported portion sizes were 3.7 g for the ASA24 and 11.8 g for the AMPM. According to the Bland-Altman-type plots, between 92% and 100% (depending on food or drink category and recall mode) of observations fell within the limits of agreement. After adjustment for multiple testing, the mean ratio of reported to true portion sizes was significantly >1 for the categories of all foods and drinks, all foods excluding liquids, amorphous or soft foods, and small pieces among AMPM respondents. Misestimation in the AMPM was significantly different from that in the ASA24 for all foods and drinks and for all foods excluding liquids. Small proportions of reported portions fell within 10% (16.2% for the ASA24 and 14.9% for the AMPM) and 25% (37.5% for the ASA24 and 33.2% for the AMPM) of truth.

CONCLUSIONS

The results raise the possibility that digital images tailored to different types and formats of foods may facilitate improved estimation of amounts eaten but highlight the need for continued work in this aspect of dietary assessment. This trial was registered at clinicaltrials.gov as NCT00978406.

Is a Picture Worth a Thousand Words? Few Evidence-Based Features of Dietary Interventions Included in Photo Diet Tracking Mobile Apps for Weight Loss

BACKGROUND

Apps using digital photos to track dietary intake and provide feedback are common, but currently there has been no research examining what evidence-based strategies are included in these apps.

METHODS

A content analysis of mobile apps for photo diet tracking was conducted, including whether effective techniques for interventions promoting behavior change, including self-regulation, for healthy eating (HE) are targeted. An initial search of app stores yielded 34 apps (n = 8 Android and Apple; n = 11 Android; n = 15 Apple). One app was removed (unable to download), and other apps (n = 4) were unable to be rated (no longer available). Remaining apps (n = 29) were downloaded, reviewed, and coded by 2 independent reviewers to determine the number of known effective self-regulation and other behavior change techniques included. The raters met to compare their coding of the apps, calculate interrater agreement, resolve any discrepancies, and come to a consensus.

RESULTS

Six apps (21%) did not utilize any of the behavior change techniques examined. Three apps (10%) provided feedback to users via crowdsourcing or collective feedback from other users and professionals, 7 apps (24%) used crowdsourcing or collective feedback, 1 app (3%) used professionals, and 18 apps (62%) did not provide any dietary feedback to users.

CONCLUSION

Few photo diet-tracking apps include evidence-based strategies to improve dietary intake. Use of photos to self-monitor dietary intake and receive feedback has the potential to reduce user burden for self-monitoring, yet photo diet tracking apps need to incorporate known effective behavior strategies for HE, including self-regulation.

Development and Validation of a Photographic Method to Use for Dietary Assessment in School Settings

OBJECTIVE

To develop and validate a photographic method aimed at making assessment of dietary intake in school canteens non-obstrusive, practical and feasible.

METHODS

The study was conducted in two elementary schools representing two different school canteen systems; main dish being served by canteen staff (Iceland), and complete self-serving (Sweden). Food items in serving and leftovers were weighed and photographed. Trained researchers estimated weights of food items by viewing the photographs and comparing them with pictures of half and full reference portions with known weights. Plates of servings and leftovers from 48 children during five school days (n = 448 plates) and a total of 5967 food items were estimated. The researchers' estimates were then compared with the true weight of the foods and the energy content calculated.

RESULTS

Weighed and estimated amounts correlated across meals both in grams and as total energy (0.853-0.977, p<0.001). The agreement between estimated energy content in school meals was close to the true measurement from weighed records; on average 4-19 kcal below true values. Organisation of meal service impacted the efficacy of the method as seen in the difference between countries; with Iceland (served by canteen staff) having higher rate of acceptable estimates than Sweden (self-serving), being 95% vs 73% for total amount (g) in serving. Iceland more often had serving size between or above the half and full reference plates compared with Sweden.

CONCLUSIONS

The photographic method provides acceptable estimates of food and energy intake in school canteens. However, greater accuracy can be expected when foods are served by canteen staff compared with self-serving.

Design and usability evaluation of user-centered and visual-based aids for dietary food measurement on mobile devices in a randomized controlled trial

OBJECTIVE

We designed and developed two interactive apps interfaces for dietary food measurements on mobile devices. The user-centered designs of both the IPI (interactive photo interface) and the SBI (sketching-based interface) were evaluated. Four types of outcomes were assessed to evaluate the usability of mobile devices for dietary measurements, including accuracy, absolute weight differences, and the response time to determine the efficacy of food measurements.

METHODS

The IPI presented users with images of pre-determined portion sizes of a specific food and allowed users to scan and then select the most representative image matching the food that they were measuring. The SBI required users to relate the food shape to a readily available comparator (e.g., credit card) and scribble to shade in the appropriate area. A randomized controlled trial was conducted to evaluate their usability.

RESULTS

A total of 108 participants were randomly assigned into the following three groups: the IPI (n=36) and SBI (n=38) experimental groups and the traditional life-size photo (TLP) group as the control. A total of 18 types of food items with 3-4 different weights were randomly selected for assessment by each type. The independent Chi-square test and t-test were performed for the dichotomous and continuous variable analyses, respectively. The total accuracy rates were 66.98%, 44.15%, and 72.06% for the IPI, SBI, and TLP, respectively. No significant difference was observed between the IPI and TLP, regardless of the accuracy proportion or weight differences. The SBI accuracy rates were significantly lower than the IPI and TLP accuracy rates, especially for several spooned, square cube, and sliced pie food items. The time needed to complete the operation assessment by the user was significantly lower for the IPI than for the SBI.

CONCLUSION

Our study corroborates that the user-centered visual-based design of the IPI on a mobile device is comparable the TLP in terms of the usability for dietary food measurements. However, improvements are needed because both the IPI and TLP accuracies associated with some food shapes were lower than 60%. The SBI is not yet a viable aid. This innovative alternative required further improvements to the user interface.

Analysis of energy metabolism in humans: A review of methodologies

Background

Obesity is a consequence of chronic energy imbalance. We need accurate and precise measurements of energy intake and expenditure, as well as the related behaviors, to fully understand how energy homeostasis is regulated in order to develop interventions and evaluate their effectiveness to combat the global obesity epidemic.

Scope of review

We provide an in-depth review of the methodologies currently used to measure energy intake and expenditure in humans, including their principles, advantages, and limitations in the clinical research setting. The aim is to provide researchers with a comprehensive guide to conduct obesity research of the highest possible quality.

Major conclusions

An array of methodologies is available to measure various aspects of energy metabolism and none is perfect under all circumstances. The choice of methods should be specific to particular research questions with practicality and quality of data the priorities for consideration. A combination of complementary measurements may be preferable. There is an imperative need to develop new methodologies to improve the accuracy and precision of energy intake assessments.

•

Image-based technology is a significant step to improve energy intake measurement.

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Physical activity informs patterns but not absolute energy expenditure.

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Combining complementary measurements overcomes shortfalls of individual methods.

Energy and Nutrient Timing for Weight Control: Does Timing of Ingestion Matter?

Over the past 40 years, meal skipping and snacking in US adults have increased, and currently most eating occasions occur later in the day than previously. Whether these changes have played a causal role in the obesity epidemic is poorly understood. Observational studies are largely inconclusive due to methodological limitations. Experimental evidence does not support a causal role for eating frequency or breakfast skipping in weight control. Emerging evidence suggests that eating irregularity and eating later in the day may be detrimental for weight control, but more studies are needed. This article summarizes studies and highlights areas needing attention.

Development and validation of a food photography manual, as a tool for estimation of food portion size in epidemiological dietary surveys in Tunisia

BACKGROUND

Estimation of food portion sizes has always been a challenge in dietary studies on free-living individuals. The aim of this work was to develop and validate a food photography manual to improve the accuracy of the estimated size of consumed food portions.

METHODS

A manual was compiled from digital photos of foods commonly consumed by the Tunisian population. The food was cooked and weighed before taking digital photographs of three portion sizes. The manual was validated by comparing the method of 24-hour recall (using photos) to the reference method [food weighing (FW)]. In both the methods, the comparison focused on food intake amounts as well as nutritional issues. Validity was assessed by Bland-Altman limits of agreement. In total, 31 male and female volunteers aged 9-89 participated in the study.

RESULTS

We focused on eight food categories and compared their estimated amounts (using the 24-hour recall method) to those actually consumed (using FW). Animal products and sweets were underestimated, whereas pasta, bread, vegetables, fruits, and dairy products were overestimated. However, the difference between the two methods is not statistically significant except for pasta (p<0.05) and dairy products (p<0.05). The coefficient of correlation between the two methods is highly significant, ranging from 0.876 for pasta to 0.989 for dairy products. Nutrient intake calculated for both methods showed insignificant differences except for fat (p<0.001) and dietary fiber (p<0.05). A highly significant correlation was observed between the two methods for all micronutrients. The test agreement highlights the lack of difference between the two methods.

CONCLUSION

The difference between the 24-hour recall method using digital photos and the weighing method is acceptable. Our findings indicate that the food photography manual can be a useful tool for quantifying food portion sizes in epidemiological dietary surveys.

School meal provision, health, and cognitive function in a Nordic setting - the ProMeal-study: description of methodology and the Nordic context

BACKGROUND

School meals, if both nutritious and attractive, provide a unique opportunity to improve health equality and public health.

OBJECTIVE

To describe the study rationale, data collection, and background of participants in the study 'Prospects for promoting health and performance by school meals in Nordic countries' (ProMeal). The general aim was to determine whether overall healthiness of the diet and learning conditions in children can be improved by school lunches, and to capture the main concerns regarding school lunches among children in a Nordic context.

DESIGN

A cross-sectional, multidisciplinary study was performed in Finland, Iceland, Norway, and Sweden on pupils (n=837) born in 2003.

RESULTS

In total 3,928 pictures of school lunches were taken to capture pupils' school lunch intake. A mean of 85% of all parents responded to a questionnaire about socioeconomic background, dietary intake, and habitual physical activity at home. Cognitive function was measured on one occasion on 93% of the pupils during optimal conditions with a Stroop and a Child Operation Span test. A mean of 169 pupils also did an Integrated Visual and Auditory Continuous Performance Test after lunch over 3 days. In total, 37,413 10-sec observations of classroom learning behavior were performed. In addition, 753 empathy-based stories were written and 78 focus groups were conducted. The pupils had high socioeconomic status.

CONCLUSIONS

This study will give new insights into which future interventions are needed to improve pupils' school lunch intake and learning. The study will provide valuable information for policy making, not least in countries where the history of school meals is shorter than in some of the Nordic countries.

Using Personal Mobile Phones to Assess Dietary Intake in Free-Living Adolescents: Comparison of Face-to-Face Versus Telephone Training

Background

Traditional paper-based methods to assess food intake can be cumbersome for adolescents; use of mobile phones to track and photograph what they eat may be a more convenient, reliable, and compelling way to collect data.

Objective

Our aims were to determine (1) the feasibility of using personal mobile phones to send food records with digital images (FRDIs) among free-living adolescents and (2) whether the quality of food records differed between a high-level intervention group (ie, face-to-face training plus real-time support) and a low-level intervention group (ie, telephone training plus next-day follow-up).

Methods

Adolescents (N=42, 11 males and 31 females) aged 12-18 years who had a mobile phone with camera enrolled in the study via consecutive sampling. The first group (n=21) received face-to-face training while the second group (n=21) was trained via telephone. Participants received a fiducial marker (FM) and completed a 1-day FRDI using their mobile phones. At every eating occasion, participants were to (1) take clear images of their meals/food with a correctly placed fiducial marker before eating, (2) send the image immediately to a designated email address, (3) right after completing a meal, send a text message listing the time and name of the meal, foods eaten, and amounts eaten, and (4) before sleep, send an “end” text message to indicate completion of food recording. Those who received face-to-face training received real-time support during reporting; those trained by telephone received next-day follow-up. Descriptive statistics and comparison tests were used to determine performance of the groups.

Results

All participants (N=42) who underwent training completed their 1-day FRDI. A significantly greater proportion of the low-level intervention group compared to the high-level intervention group placed their FM correctly in the image (95% vs 43%, P<.001), had complete information for each meal in their food record (95% vs 71%, P=.04), and had a higher overall score in meeting the criteria for food recording (4.3 vs 3.4 out of 5 points). Both groups had energy intake values that moderately correlated with their estimated energy requirements: low-intervention r=.55; high-intervention r=.51.

Conclusions

Using personal mobile phones to report dietary intake via texting and digital images is feasible among free-living adolescents. Real-time support or high-level intervention does not guarantee better food recording quality among adolescents.

Adaptation of Locally Available Portion Sizes for Food Frequency Questionnaires in Nutritional Epidemiological Studies: How Much Difference does it Make?

Introduction:

There is need for employing strategies to minimize measurement errors while administering semi-quantitative FFQ. The current study was planned to adapt and standardize locally available portion sizes for semi-quantitative FFQ to improve its validity and document the process of standardization of portion sizes.

Methodology:

The study was conducted in 9 villages of the INCLEN-SOMAARTH DDESS (Demographic, Development and Environmental Surveillance Site), Palwal district, Haryana, India. The subjects in these nine villages are part of a cohort study to assess the interaction between societal and household factors with food intake and physical activity of children. Systematic utensil survey was undertaken in 3 randomly chosen households per village i.e. 27 households and the portion sizes were derived from a total of 74 serving utensils. The derived sizes were classified as small (240 ml), medium (320 ml) and large (600 ml). The semi-quantitative FFQ with locally derived portion sizes was then administered to 63 children in 6-12 year age group.

Results:

The volume of food measured by the reference portion sizes generally being employed in the national surveys, would have been underestimated the food consumed by the child by 55-60% as compared to what was being consumed by the children in the study area. The correlation between food intake assessed by 24-hr recall method and FFQ using derived (local) portion sizes was better as compared to that obtained with the semi-quantitative FFQ done with reference portions.

Conclusion:

In conclusion, local portion size adaptation of FFQ for semi-quantification is useful to mitigate measurement errors associated with this technique.

Perspective: Randomized Controlled Trials Are Not a Panacea for Diet-Related Research

Research into the role of diet in health faces a number of methodologic challenges in the choice of study design, measurement methods, and analytic options. Heavier reliance on randomized controlled trial (RCT) designs is suggested as a way to solve these challenges. We present and discuss 7 inherent and practical considerations with special relevance to RCTs designed to study diet: 1) the need for narrow focus; 2) the choice of subjects and exposures; 3) blinding of the intervention; 4) perceived asymmetry of treatment in relation to need; 5) temporal relations between dietary exposures and putative outcomes; 6) strict adherence to the intervention protocol, despite potential clinical counter-indications; and 7) the need to maintain methodologic rigor, including measuring diet carefully and frequently. Alternatives, including observational studies and adaptive intervention designs, are presented and discussed. Given high noise-to-signal ratios interjected by using inaccurate assessment methods in studies with weak or inappropriate study designs (including RCTs), it is conceivable and indeed likely that effects of diet are underestimated. No matter which designs are used, studies will require continued improvement in the assessment of dietary intake. As technology continues to improve, there is potential for enhanced accuracy and reduced user burden of dietary assessments that are applicable to a wide variety of study designs, including RCTs.

Too much of a good thing? Overexertion of self-control and dietary adherence in individuals with Type 2 diabetes

OBJECTIVES

The resource model of self-control posits that self-control is a finite resource that can be depleted. Individuals with diabetes must continually restrict their diet, requiring self-control. As a result, dietary adherence is difficult, and lapses are common. People with diabetes who overexert self-control following a lapse may be especially likely to experience a subsequent relapse, as suggested by the resource model. This investigation used the resource model of self-control to test whether overexertion of dietary self-control following a lapse would be predictive of a subsequent relapse in dietary control.

DESIGN

We tested this prediction in a daily diary study of 128 individuals with diabetes (Mage  = 66.12).

METHODS

Participants' reports of their daily dietary adherence were used to define lapses in adherence, post-lapse adherence, and relapses.

RESULTS

Individuals who overexerted self-control after a lapse were more likely to experience a subsequent relapse (OR = 3.276, p = .016) and to do so sooner (HR = 2.12, p = .023).

CONCLUSIONS

People with diabetes may seek to compensate for a lapse in adherence by overexerting self-control, but doing so may deplete their self-control and increase the risk of a future relapse. Statement of contribution What is already known on this subject? The resource model of self-control posits that self-control is a limited resource that can be temporarily depleted. Numerous experimental studies have demonstrated support for this model showing that when participants are instructed to engage in a self-control task, they produce less self-control on a subsequent task. The majority of the existing studies are not conducted in naturalistic settings and do not use patient populations. What does this study add? This study is an ecologically valid test of the resource model of self-control. This study applies the resource model of self-control to a patient population.

A Mobile Phone Based Method to Assess Energy and Food Intake in Young Children: A Validation Study against the Doubly Labelled Water Method and 24 h Dietary Recalls

Mobile phones are becoming important instruments for assessing diet and energy intake. We developed the Tool for Energy Balance in Children (TECH), which uses a mobile phone to assess energy and food intake in pre-school children. The aims of this study were: (a) to compare energy intake (EI) using TECH with total energy expenditure (TEE) measured via doubly labelled water (DLW); and (b) to compare intakes of fruits, vegetables, fruit juice, sweetened beverages, candy, ice cream, and bakery products using TECH with intakes acquired by 24 h dietary recalls. Participants were 39 healthy, Swedish children (5.5 ± 0.5 years) within the ongoing Mobile-based Intervention Intended to Stop Obesity in Preschoolers (MINISTOP) obesity prevention trial. Energy and food intakes were assessed during four days using TECH and 24 h telephone dietary recalls. Mean EI (TECH) was not statistically different from TEE (DLW) (5820 ± 820 kJ/24 h and 6040 ± 680 kJ/24 h, respectively). No significant differences in the average food intakes using TECH and 24 h dietary recalls were found. All food intakes were correlated between TECH and the 24 h dietary recalls (ρ = 0.665-0.896, p < 0.001). In conclusion, TECH accurately estimated the average intakes of energy and selected foods and thus has the potential to be a useful tool for dietary studies in pre-school children, for example obesity prevention trials.