Digital photography: a new method for estimating food intake in cafeteria settings

Exploring healthy eating among ethnic minority students using mobile technology: Feasibility and adherence

Interventions aiming to help ethnically diverse emerging adults engage in healthy eating have had limited success. The aim of this study was to assess the feasibility of and adherence to an intervention capitalizing on mobile technology to improve healthy eating. Participants created an online photo food journal and received motivational text messages three times a day. Satisfaction with the intervention was assessed, as were control variables including depression and body dissatisfaction. In addition, weight and height were measured. Levels of adherence to the photo food journal were high with approximately two photos posted a day at baseline. However, adherence rates decreased over the course of the study. Body dissatisfaction positively predicted adherence, while body mass index negatively predicted study satisfaction. Mobile technology provides innovative avenues for healthy eating interventions. Such interventions appear acceptable and feasible for a short period; however, more work is required to evaluate their viability regarding long-term engagement.

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

Images captured during eating episodes provide objective information to assist in the assessment of dietary intake. Images are captured using handheld devices or wearable cameras, and can support traditional self-report or provide the primary record of dietary intake. A diverse range of image-assisted methods have been developed and evaluated but have not been previously examined together. Therefore, a review was undertaken to examine all studies that have evaluated or validated image-assisted methods of dietary assessment for assessing dietary energy intake. Identified image-assisted methods that employ similar methodologies were grouped for comparison. English-language full-text research articles published between January 1998 and November 2013 were searched using five electronic databases. A search of reference lists and associated websites was also conducted. Thirteen studies that evaluated 10 unique image-assisted methods among adults aged 18 to 70 years were included. Ten studies used handheld devices and three studies used wearable cameras. Eight studies evaluated image-based food records, two studies explored the use of images to enhance written food records, and three studies evaluated image-assisted 24-hour dietary recalls. Results indicate images enhance self-report by revealing unreported foods and identify misreporting errors not captured by traditional methods alone. Moreover, when used as the primary record of dietary intake, images can provide valid estimates of energy intake. However, image-assisted methods that rely on image analysis can be prone to underestimation if users do not capture images of satisfactory quality before all foods are consumed. Further validation studies using criterion measures are warranted. The validity among children, adolescents, and elderly persons as well as the feasibility of using image-assisted methods in large samples needs to be examined. Additional research is also needed to better understand the potential applications and pitfalls of wearable cameras.

Reliability and validity of digital imaging as a measure of schoolchildren's fruit and vegetable consumption

BACKGROUND

As more and more interventions aim to increase schoolchildren's fruit and vegetable (FV) consumption, less resource-intensive yet valid alternatives to weighed plate waste (WPW) are needed for assessing dietary intake.

OBJECTIVES

We aimed to test the reliability and validity of digital imaging (DI) and digital imaging with observation (DI+O) in assessing children's FV consumption during school lunch.

DESIGN

FV consumption (in grams) was assessed on lunch trays from third- to fifth-grade children over eight visits (31 to 68 trays collected per visit) to compare WPW with DI and DI+O.

SETTING

Two elementary schools (327 and 631 students enrolled, respectively).

MAIN OUTCOME MEASURES

Interobserver reliability of DI. Validity of DI and DI+O compared against WPW.

STATISTICAL ANALYSES

Reliability was assessed by percent agreement and intraclass correlation coefficients (ICCs). Validity was assessed by Pearson correlations, paired t tests, and Bland-Altman plots.

RESULTS

Reliability was acceptable for DI; percent agreement was 96% and the ICC was 0.92. FV consumption assessments by DI and WPW (n=159) were highly correlated (r=0.96; P<0.001). Mean FV consumption using DI (96.7 g) was within 1.0 g of WPW and not significantly different from WPW (P=0.56), and Bland-Altman limits of agreement for individual-tray FV consumption were -32.9 to 31.3 g. FV consumption assessments by DI+O and WPW were highly correlated (r=0.98; P<0.001). Mean FV consumption using DI+O (99.3 g) was within 1.0 g of WPW and not significantly different from WPW (P=0.38), and limits of agreement for individual-tray FV consumption were -25.0 to 26.8 g.

CONCLUSIONS

DI was reliable for assessing children's FV consumption during school lunch. DI and DI+O were valid for assessing mean consumption but less precise for estimating individual-tray consumption. Valid estimations of mean FV consumption were achieved using DI without cafeteria observations, thereby reducing labor and time. Thus, DI is especially promising for assessing children's mean FV consumption during school lunch.

Impact of a Smarter Lunchroom intervention on food selection and consumption among adolescents and young adults with intellectual and developmental disabilities in a residential school setting

OBJECTIVE

To assess whether a Smarter Lunchroom intervention based on behavioural economics and adapted for students with intellectual and developmental disabilities would increase the selection and consumption of fruits, vegetables and whole grains, and reduce the selection and consumption of refined grains.

DESIGN

The 3-month intervention took place at a residential school between March and June 2012. The evaluation employed a quasi-experimental, pre-post design comparing five matched days of dietary data. Selection and plate waste of foods at lunch were assessed using digital photography. Consumption was estimated from plate waste.

SETTING

Massachusetts, USA.

SUBJECTS

Students (n 43) aged 11-22 years with intellectual and developmental disabilities attending a residential school.

RESULTS

Daily selection of whole grains increased by a mean of 0·44 servings (baseline 1·62 servings, P = 0·005) and refined grains decreased by a mean of 0·33 servings (baseline 0·82 servings, P = 0·005). The daily consumption of fruits increased by a mean of 0·18 servings (baseline 0·39 servings, P = 0·008), whole grains increased by 0·38 servings (baseline 1·44 servings, P = 0·008) and refined grains decreased by a mean of 0·31 servings (baseline 0·68 servings, P = 0·004). Total kilojoules and total gram weight of food selected and consumed were unchanged. Fruit (P = 0·04) and vegetable (P = 0·03) plate waste decreased.

CONCLUSIONS

A Smarter Lunchroom intervention significantly increased whole grain selection and consumption, reduced refined grain selection and consumption, increased fruit consumption, and reduced fruit and vegetable plate waste. Nudge approaches may be effective for improving the food selection and consumption habits of adolescents and young adults with intellectual and developmental disabilities.

Effectiveness of offering healthy labelled meals in improving the nutritional quality of lunch meals eaten in a worksite canteen

Healthier meal selections at restaurants and canteens are often limited and not actively promoted. In this Danish study the effectiveness of a healthy labelling certification program in improving dietary intake and influencing edible plate waste was evaluated in a quasi-experimental study design. Employees from an intervention worksite canteen and a matched control canteen were included in the study at baseline (February 2012), after completing the certification process (end-point) and six month from end-point (follow-up) (total n=270). In order to estimate nutrient composition of the consumed lunch meals and plate waste a validated digital photographic method was used combining estimation of food intake with food nutrient composition data. Food satisfaction was rated by participants using a questionnaire. Several significant positive nutritional effects were observed at the intervention canteen including a mean decrease in energy density in the consumed meals from 561kJ/100g at baseline to 368 and 407kJ/100g at end-point and follow-up, respectively (P<0.001). No significant changes were seen with regard to food satisfaction and plate waste. In the control canteen no positive nutritional effects were observed. The results of the study highlight the potential of using healthy labelling certification programs as a possible driver for increasing both the availability and awareness of healthy meal choices, thereby improving dietary intake when eating out.

Digital photography as an educational food logging tool in obese patients with type 2 diabetes: lessons learned from a randomized, crossover pilot trial

PURPOSE

The purpose of this pilot study is to investigate the utility of, and areas of refinement for, digital photography as an educational tool for food logging in obese patients with type 2 diabetes (T2DM).

METHODS

Thirty-three patients aged 18 to 70 with T2DM, body mass index at least 30 kg/m(2), and A1C 7.5% to 9% were recruited from an endocrinology clinic and randomized to a week of food logging using a digital camera (DC) or paper diary (PD), crossing over for week 2. Patients then viewed a presentation about dietary effects on blood glucose, using patient DC and blood glucose entries. Outcomes of adherence (based on number of weekly entries), changes in mean blood glucose and frequency of blood glucose checks, and patient satisfaction were compared between methods. Patient feedback on the DC intervention and presentation was also analyzed.

RESULTS

Thirty patients completed the study. Adherence was identical across methods. The mean difference in number of entries was not significant between methods. This difference increased and neared statistical significance (favoring DC) among patients who were adherent for at least 1 week (21 entries, with 2 entries per day for 5 of 7 days, n = 25). Mean blood glucose did not significantly decrease in either method. Patient satisfaction was similar between interventions. Feedback indicated concerns over photograph accuracy, forgetting to use the cameras, and embarrassment using them in public.

CONCLUSION

Although the DC method was comparable to PD in adherence, blood glucose changes, and patient satisfaction in this pilot trial, patient feedback suggested specific areas of refinement to maximize utility of DC-based food logging as an educational tool in T2DM.

Measuring food intake with digital photography

The digital photography of foods method accurately estimates the food intake of adults and children in cafeterias. When using this method, images of food selection and leftovers are quickly captured in the cafeteria. These images are later compared with images of 'standard' portions of food using computer software. The amount of food selected and discarded is estimated based upon this comparison, and the application automatically calculates energy and nutrient intake. In the present review, we describe this method, as well as a related method called the Remote Food Photography Method (RFPM), which relies on smartphones to estimate food intake in near real-time in free-living conditions. When using the RFPM, participants capture images of food selection and leftovers using a smartphone and these images are wirelessly transmitted in near real-time to a server for analysis. Because data are transferred and analysed in near real-time, the RFPM provides a platform for participants to quickly receive feedback about their food intake behaviour and to receive dietary recommendations for achieving weight loss and health promotion goals. The reliability and validity of measuring food intake with the RFPM in adults and children is also reviewed. In sum, the body of research reviewed demonstrates that digital imaging accurately estimates food intake in many environments and it has many advantages over other methods, including reduced participant burden, elimination of the need for participants to estimate portion size, and the incorporation of computer automation to improve the accuracy, efficiency and cost-effectiveness of the method.

Characterizing lunch meals served and consumed by pre-school children in Head Start

OBJECTIVE

To examine the variability of food portions served and consumed by African-American and Hispanic-American pre-school children attending Head Start.

DESIGN

Cross-sectional.

SETTING

Food consumption by pre-schoolers (n 796) enrolled in sixteen Head Start centres in Houston, Texas (51 % boys, 42 % African-American, mean age 4 years) were assessed during 3 d of lunch meals using digital photography. Descriptive statistics and multilevel regression models, adjusting for classroom and school clustering effects, were determined.

SUBJECTS

Head Start pre-schoolers aged 3–5 years.

RESULTS

Mean amount served was 2428 kJ (580 kcal) and 572 g. Mean intake was 1421 kJ (339 kcal) and 331 g: 20 % protein, 46 % carbohydrate and 34 % fat. Plate waste was 43 % (range: 38 % (fruit) to 61 % (vegetables)). Mean CV of food served was 29 %: 33 % for entrées, 44 % for vegetables, 60 % for fruit and 76 % for starches. Mean CV of food consumed was 46 %: 58 % for entrées, 86 % for fruit, 96 % for vegetables and 111 % for starches. Total gram amount of food served was positively correlated with consumption (r = 0·43, P < 0·001).

CONCLUSIONS

Plate waste and variation in amounts served and consumed were substantial; amounts served were associated with amounts consumed. Large portion sizes may contribute to paediatric obesity by promoting excessive intake at meals. Understanding factors influencing portion sizes provides insight about specific intervention strategies that can be used in obesity prevention programmes.

Effects of modified foodservice practices in military dining facilities on ad libitum nutritional intake of US army soldiers

BACKGROUND

Modifying foodservice practices in military dining facilities could influence ad libitum nutritional intake patterns of soldiers.

OBJECTIVE

We aimed to determine how changes in foodservice operations consistent with 2005 Dietary Guidelines for Americans affected soldiers' ad libitum nutritional intake in military dining facilities (DFACs).

DESIGN

Ten DFACs participated, and the intervention was implemented in five DFACs in an independently sampled, partial crossover design. Nutrient intake of diners was assessed during a test meal using digital photography, and customer satisfaction with foodservice was assessed via surveys at baseline (n=602), and again at 6 months (n=519) and 12 months (n=458) after the intervention was implemented.

PARTICIPANTS

Volunteers were US Army active duty soldiers recruited from among diners at 10 DFACs on Fort Bragg, NC.

MAIN OUTCOME MEASURES

Primary outcomes were intakes of energy and total fat, and percent energy from fat and saturated fat. Differences between diners' intakes in control and intervention DFACs were assessed using independent samples t tests.

RESULTS

At 6 months after implementing the intervention, diners at intervention DFACs had significantly lower lunchtime intakes of energy (945±338 kcal vs 1,061±380 kcal), total fat (38±19 g vs 47±25 g), percent energy from fat (35%±10% vs 39%±11%) and saturated fat (4.7%±1.7% vs 5.6%±2.3%), discretionary fat (30±18 g vs 39±24 g), and refined grains (2.3±1.7 oz equivalents vs 2.8±2.4 oz equivalents) compared with diners at control DFACs. Further, diners at intervention DFACs rated customer satisfaction higher than diners at control DFACs.

CONCLUSIONS

These findings suggest that modest changes in military DFAC serving practices to promote healthy eating and food selection can facilitate positive changes in soldiers' nutritional intake.

Modification of the school cafeteria environment can impact childhood nutrition. Results from the Wise Mind and LA Health studies

Recent changes in nutrition standards for the National School Lunch and School Breakfast Programs assume that modification of the nutritional serving practices of school cafeterias will result in improved childhood nutrition in the school environment. The primary aim of this paper is to summarize the findings from two recent cluster randomized controlled trials (Wise Mind and LA Health) that tested the hypothesis that modification of school cafeteria environments, including changes in nutrition standards, would yield beneficial changes in childhood nutrition and healthy eating in the school lunch environment. A secondary aim was to investigate the association of participant characteristics and changes in nutrition and healthy eating. A third aim was to investigate the relationships between the food intake of children and: (1) foods selected by the children and (2) food that was uneaten during the lunch meal (plate waste). The studies used similar approaches for modifying the school cafeteria environment and both studies used the digital photography method to measure changes in food intake, food selection, and plate waste. Both studies reported significant improvements in childhood nutrition, and the LA Health study reported improved healthy eating, following introduction of the cafeteria modification program in comparison to baseline and/or control arms. These studies confirm the hypothesis that interventions that modify the school cafeteria environment can beneficially impact childhood nutrition.

Characterizing dinner meals served and consumed by low-income preschool children

BACKGROUND

A dinner meal is consumed by approximately 95% of preschool children, yet few studies have characterized the dinner meal within a broader environmental context. The primary goal of this study was to identify the average quantities of foods served and consumed at the dinner meal by preschool children. A secondary goal was to look at factors that influenced the total amounts of food and energy consumed among preschoolers at the dinner meal.

METHOD

Food intake at a family dinner meal was measured using digital photography in African-American and Hispanic-American preschool children (n = 231). Pictorial records were converted to gram and energy estimates of food served and consumed; grams were converted to kilocalories for each food using Nutrition Data System for Research (NDSR) nutritional software. Foods were categorized by groups/subgroups. Comparison of means and coefficient of variation was examined overall and by food groups for food grams (and energy) served, consumed, and wasted. The relationship of mother/child characteristics to amounts served and consumed were analyzed by regression and analysis of variance (ANOVA).

RESULTS

Plate waste was high; 30% of the foods served to the child at the dinner meal were not consumed. The amounts of food and beverage served and consumed varied within and among the food groups studied. The proportion of children served a major food group at the dinner meal varied considerably: 44% fruit/juice, 97% vegetables, 99% grains, 97% meats, 74% dairy, 66% sweetened beverages, 92% fat and oils, and 40% sweets and sugars. The amount of food served was positively associated with the amount consumed (p < 0.0001). Energy density of the dinner meal was positively associated with energy intake consumed (p < 0.0001).

CONCLUSIONS

Plate waste and variation in amounts served and consumed was substantial. The amount of food served was positively associated with the amount of food consumed by preschool children.

Validity and feasibility of a digital diet estimation method for use with preschool children: a pilot study

OBJECTIVE

The goal of the study was to assess the validity and feasibility of a digital diet estimation method for use with preschool children in Head Start.

METHODS

Preschool children and their caregivers participated in validation (n = 22) and feasibility (n=24) pilot studies. Validity was determined in the metabolic research unit using actual gram weight measurements as the reference method. Feasibility of using the digital diet estimation method was determined in Head Start and in the home by assessing 3 separate lunch and dinner meals.

RESULTS

The average correlation between estimated weights and actual weights was 0.96 (P < .001), and the average mean difference was 10.6 g. The digital diet estimates were 5% lower than the actual weights.

CONCLUSIONS AND IMPLICATIONS

The digital diet estimation method may be a valid and feasible method for assessing food intake of preschool children.

Dietary Digital Diaries: Documenting Adolescents' Obesogenic Environment

Obesogenic built environments may contribute to excessive eating and obesity. Twenty-three 12- to 17-year-old low-income African American adolescents created digital diaries by photographing their lunchtime food environment in a summer academic program. Digitally depicted foods were classified as appearing on the platescape (student's or others' plate) or the tablescape (food buffet). Height, weight, BMI percentile, and waist-to-hip ratio were calculated at baseline and week 4. Adolescents digitally depicted high caloric, high fat foods on the platescape and tablescape, particularly adolescents with a higher waist-to-hip ratio. Weight gain during the 4-week program was significantly predicted by the number of calories and the amount of fat content depicted on the student's plates. Digital diaries, then, can document adolescents' perspectives of their food environments that promote their overconsumption of high caloric and high fat foods that contribute to weight gain and put them at risk for obesity.

Validity of the Remote Food Photography Method (RFPM) for estimating energy and nutrient intake in near real-time

Two studies are reported; a pilot study to demonstrate feasibility followed by a larger validity study. Study 1's objective was to test the effect of two ecological momentary assessment (EMA) approaches that varied in intensity on the validity/accuracy of estimating energy intake (EI) with the Remote Food Photography Method (RFPM) over 6 days in free-living conditions. When using the RFPM, Smartphones are used to capture images of food selection and plate waste and to send the images to a server for food intake estimation. Consistent with EMA, prompts are sent to the Smartphones reminding participants to capture food images. During Study 1, EI estimated with the RFPM and the gold standard, doubly labeled water (DLW), were compared. Participants were assigned to receive Standard EMA Prompts (n = 24) or Customized Prompts (n = 16) (the latter received more reminders delivered at personalized meal times). The RFPM differed significantly from DLW at estimating EI when Standard (mean ± s.d. = -895 ± 770 kcal/day, P < 0.0001), but not Customized Prompts (-270 ± 748 kcal/day, P = 0.22) were used. Error (EI from the RFPM minus that from DLW) was significantly smaller with Customized vs. Standard Prompts. The objectives of Study 2 included testing the RFPM's ability to accurately estimate EI in free-living adults (N = 50) over 6 days, and energy and nutrient intake in laboratory-based meals. The RFPM did not differ significantly from DLW at estimating free-living EI (-152 ± 694 kcal/day, P = 0.16). During laboratory-based meals, estimating energy and macronutrient intake with the RFPM did not differ significantly compared to directly weighed intake.

Uso de imagens de alimentos na avaliação do consumo alimentar

Discutem-se, neste estudo, abordagens metodológicas que utilizam tecnologias de informação e comunicação para a avaliação do consumo alimentar por meio de fotografias ou filmagem dos alimentos. Foram pesquisados artigos nas bases de dados ScienceDirect, Scopus, SciELO e MedLine/PubMed, utilizando-se, sem limitação temporal, em português e inglês, as palavras-chave: "foto/fotografia" ou "filmagem" conjugadas a "digital", "alimento", "tamanho da porção", "refeição" e/ou "ingestão alimentar", bem como a associação desses ter-mos com: "precisão", "validade" e "validação". Das referências consultadas, foram analisados 21 artigos que atenderam ao critério estabelecido. Pelo resultado da pesquisa, é possível afirmar que o método fotográfico pode ser aplicado mediante registro das porções de referência, servidas e rejeitadas, com posterior transmissão ao computador. Assim, os observadores treinados não precisam, necessariamente, acompanhar o momento da refeição. Tal método apresenta validação e acurácia aceitáveis para a estimativa do tamanho das porções quando comparado ao método de estimativa visual direta e de pesagem de alimentos. Outra abordagem emprega computador portátil com câmera fotográfica e celular integrados, contendo programa dietético projetado para registro e automonitoração da ingestão alimentar. Esse instrumento possibilita a transmissão de informações diárias sobre a ingestão de alimentos e bebidas em locais variados, auxiliando a coleta de dados em estudos populacionais. A abordagem em desenvolvimento inclui a utilização de dispositivo de com-putação móvel para registro fotográfico das refeições, com determinação automática dos alimentos consumidos. Também se discutem tentativas para investigar o comportamento espontâneo de comensais por meio de filmagem, reconhecimento facial e informações obtidas nas caixas registradoras em um restaurante modelo.

Trial of a mobile phone method for recording dietary intake in adults with type 2 diabetes: evaluation and implications for future applications

We evaluated a mobile phone application (Nutricam) for recording dietary intake. It allowed users to capture a photograph of food items before consumption and store a voice recording to explain the contents of the photograph. This information was then sent to a website where it was analysed by a dietitian. Ten adults with type 2 diabetes (BMI 24.1-47.9 kg/m(2)) recorded their intake over a three-day period using both Nutricam and a written food diary. Compared to the food diary, energy intake was under-recorded by 649 kJ (SD 810) using the mobile phone method. However, there was no trend in the difference between dietary assessment methods at levels of low or high energy intake. All subjects reported that the mobile phone system was easy to use. Six subjects found that the time taken to record using Nutricam was shorter than recording using the written diary, while two reported that it was about the same. The level of detail provided in the voice recording and food items obscured in photographs reduced the quality of the mobile phone records. Although some modifications to the mobile phone method will be necessary to improve the accuracy of self-reported intake, the system was considered an acceptable alternative to written records and has the potential to be used by adults with type 2 diabetes for monitoring dietary intake by a dietitian.

Convergent validity of a digital image-based food record to assess food group intake in youth

Current methods to assess the dietary behavior of youth have many limitations that reduce accuracy. Previous research has examined use of food images to assess nutrient intake. The objectives for this study are to validate the use of a novel digital image-based food record (DIFR) method to assess food group intake in youth and examine inter-analyst reliability. In 2009, a convenience sample of youth aged 9 to 12 years were recruited in Davis, CA, and asked to take images of the food they ate between 5 pm and bedtime for 7 days. To examine convergent validity, 1-day and average weekly food group intakes assessed by DIFR were compared to food group estimates derived from 24-hour dietary recalls. To examine interanalyst reliability, estimates of food group intakes made by two independent nutrition students were compared, using Spearman correlation coefficients. Data from 26 youth showed that each participant's 1-day food group intakes assessed by the DIFR and recall methods were significantly correlated (P<0.001) for both analysts for all food groups. Estimated average daily intake amounts determined by the DIFR method and recall methods were also significantly correlated for all food groups except grains (n=28). Interanalyst reliability was very good; estimates of food group intakes, provided by the two students, were significantly correlated (n=28, P<0.001). These results show great potential for use of DIFR to assess 1 day's intake of food groups, but more research is needed to determine how well the method performs in capturing usual intake and changes in intake.

Evaluation of a digital method to assess evening meal intake in a free-living adult population

BACKGROUND

In recent years new applications of technologies, including digital images, to capture dietary behaviour in real time have been explored.

OBJECTIVES

To validate a digital method for estimating evening meal intake in a free-living adult population, and to examine the feasibility of the method for recording evening meal intake over a prolonged period of time.

DESIGN

The digital method was compared against weighed records of 19 participants' usual evening meals for five consecutive days. Two trained image analysts independently estimated the weight of individual foods within the meals into major food categories, and the nutrient content was calculated. A second study included interviews with 28 participants recording their evening meals on weekdays for three consecutive weeks to get their perspective on the feasibility of the method.

RESULTS

High correlation coefficients between the digital method and weighed records were found for all measured food categories and nutrients. Comparable means and acceptable limits of agreement (mean difference +/- 2 SD) were found with regard to macronutrient distribution (e.g. fat content -5 to 6 E%), energy density (-75 to 91 kJ/100 g), and energy-adjusted foods (e.g. fruit and vegetable content -241 to 236 g/10 MJ). The majority of the participants expressed satisfaction with the method and were willing to record their evening meals for 1 month or more using the digital method.

CONCLUSION

The digital method is valid and feasible for evening meal estimation in real-time where a prolonged recording period of participants' meals is needed.

Children in school cafeterias select foods containing more saturated fat and energy than the Institute of Medicine recommendations

In this study, we examined if children's food selection met the School Meals Initiative (SMI) standards and the recently released Institute of Medicine (IOM) recommendations. Mean food selection, plate waste, and food intake were also examined. Food intake of 2049 4th-6th grade students was measured objectively at lunch over 3 d with digital photography in 33 schools. The percent of children whose food selection met the SMI standards and IOM recommendations for energy (kJ), fat and saturated fat, calcium, iron, and vitamin A and C were calculated. The SMI standards provide lower limits for most nutrients; the IOM provides a range of values, including an upper limit for energy. Seventy-seven percent of children's energy selection met the SMI lower limit, but only 16% of children met the IOM's recommended range and 74% of children exceeded the upper limit. More than 70% of children exceeded the SMI and IOM's saturated fat recommendations. Children selected (mean +/- SD) 3168 +/- 621 kJ, discarded 882 +/- 581 kJ, and consumed 2286 +/- 716 kJ. Children were less likely to discard fat than carbohydrate, resulting in proportionally more fat being consumed. Most children met SMI and IOM recommendations for protein, calcium, iron, and vitamin A. With few exceptions, energy selection was similar among groups of children, but plate waste differed (P < 0.001), resulting in greater energy intake among boys compared with girls, Caucasians compared with African Americans, and heavier compared with lighter children. Children's selection was high in saturated fat and, based on IOM criteria, included excess energy.

Quantification of food intake using food image analysis

Measuring free-living peoples' food intake represents methodological and technical challenges. The Remote Food Photography Method (RFPM) involves participants capturing pictures of their food selection and plate waste and sending these pictures to the research center via a wireless network, where they are analyzed by Registered Dietitians to estimate food intake. Initial tests indicate that the RFPM is reliable and valid, though the efficiency of the method is limited due to the reliance on human raters to estimate food intake. Herein, we describe the development of a semi-automated computer imaging application to estimate food intake based on pictures captured by participants.

Development and validation of a new simple Healthy Meal Index for canteen meals

OBJECTIVE

Nutrition evaluation tools should be developed both for scientific purposes and to encourage and facilitate healthy nutritional practices. The purpose of the present study was to develop and validate a simple food-based Healthy Meal Index (HMI) reflecting the nutritional profile of individual canteen meals.

DESIGN

The development process included overall model selection, setting nutritional goals and defining scoring systems and thresholds. Three index components were included: (i) contents of fruit and vegetables, (ii) fat content and quality and (iii) contents of wholegrain products and potatoes. The development was built on the principles embodied by the Plate Model, but providing more specificity in some areas. The simple HMI was validated against weighed and chemically analysed food and nutrient content of a representative sample of canteen meals. The sample was split into four categories according to the total index score and compared across categories.

SETTING

A total of 180 meals from fifteen worksite canteens.

RESULTS

Average energy density decreased significantly across categories (from 876 kJ/100 g to 537 kJ/100 g, P < 0.001). Also, the content of total and saturated fat, carbohydrate and fruit and vegetables varied across categories with higher score values being closer to dietary guidelines (P < 0.001).

CONCLUSIONS

The simple HMI was successful in ranking canteen meals according to their nutritional quality. The index provides a valuable tool to both researchers and food and nutrition professionals, e.g. caterers and dietitians, who wish to evaluate nutritional quality of meals in line with the recommendations for healthier eating without the use of nutrition calculation programs.

A novel method to remotely measure food intake of free-living individuals in real time: the remote food photography method

The aim of the present study was to report the first reliability and validity tests of the remote food photography method (RFPM), which consists of camera-enabled cell phones with data transfer capability. Participants take and transmit photographs of food selection and plate waste to researchers/clinicians for analysis. Following two pilot studies, adult participants (n 52; BMI 20-35 kg/m2 inclusive) were randomly assigned to the dine-in or take-out group. Energy intake (EI) was measured for 3 d. The dine-in group ate lunch and dinner in the laboratory. The take-out group ate lunch in the laboratory and dinner in free-living conditions (participants received a cooler with pre-weighed food that they returned the following morning). EI was measured with the RFPM and by directly weighing foods. The RFPM was tested in laboratory and free-living conditions. Reliability was tested over 3 d and validity was tested by comparing directly weighed EI to EI estimated with the RFPM using Bland-Altman analysis. The RFPM produced reliable EI estimates over 3 d in laboratory (r 0.62; P < 0.0001) and free-living (r 0.68; P < 0.0001) conditions. Weighed EI correlated highly with EI estimated with the RFPM in laboratory and free-living conditions (r>0.93; P < 0.0001). In two laboratory-based validity tests, the RFPM underestimated EI by - 4.7 % (P = 0.046) and - 5.5 % (P = 0.076). In free-living conditions, the RFPM underestimated EI by - 6.6 % (P = 0.017). Bias did not differ by body weight or age. The RFPM is a promising new method for accurately measuring the EI of free-living individuals. Error associated with the method is small compared with self-report methods.

Validity and Reliability of Photographic Diet Diaries for Assessing Dietary Intake Among Young Children

Obtaining valid, reliable dietary intake data for young children is challenging. The objective of this study was to assess the validity, reliability, and acceptability of the addition of photography to traditional written diet diaries for recording young children's dietary intake. Twenty-two parents of preschoolers enrolled to complete a 2-day photographic diet diary for their child. Diaries were coded by a trained nursing student for food weight, calories, and macronutrients. A random sample of diaries was evaluated by an independent nutritionist to determine interrater reliability. Convergent validity was tested by comparing visual estimates and actual values of photos of 24 researcher-created meals/snacks. Acceptability was assessed through participants' feedback, completion rates for the project, project costs, and quality of the data obtained. Reliability was assessed by computing intraclass correlations between caloric and macronutrient data from 2 independent diary evaluators. Convergent validity was assessed by calculating intraclass correlations between visually estimated photo diary evaluations and actual premeasured researcher-created meals/snacks. Medium to large correlations between the 2 independent evaluators (.51-.63) were found for caloric and macronutrient values, with the exception of protein (r = –.21). Strong correlations (food served, r = .69-.96; food consumed, r = .66-.83) were obtained between visual estimates and actual values of calories and macronutrients for the premeasured foods. Preliminary results indicate the addition of photographs to a traditional diet diary may enhance the validity and reliability of prospective dietary intake recording. Parents and children indicated the activity was fun, and quality data resulted, indicating that this method is acceptable.

Digital photography as a tool to measure school cafeteria consumption

BACKGROUND

Assessing actual consumption of school cafeteria meals presents challenges, given recall problems of children, the cost of direct observation, and the time constraints in the school cafeteria setting. This study assesses the use of digital photography as a technique to measure what elementary-aged students select and actually consume from school cafeteria meals.

METHODS

Before and after still digital photographs were taken of labeled trays for every lunch served to elementary students over 4 lunch periods. Two analysts visually estimated the amount of each item consumed from every tray, and those estimates were compared to evaluate interrater reliability.

RESULTS

Collection of photographic data was rapid and did not disrupt the busy elementary cafeteria setting. Analysts' estimates of consumption levels of meal components (main and side dishes) were within 10% of each other in 92% of the cases. Only 0.2% of items could not be analyzed due to children playing with food or otherwise obstructed photographs.

CONCLUSIONS

Digital photography offers researchers and school food service personnel a highly accurate and cost-effective tool to measure actual consumption of school cafeteria meals. Data collected through this method can be evaluated by simple counts of servings of produce or other food groups or by more detailed analyses of nutritional composition.

Measurement of children's food intake with digital photography and the effects of second servings upon food intake

This study tested the reliability and validity of measuring children's food intake with the digital photography method and the effects of second servings upon food intake. Food intake was measured in a school cafeteria for 5 days. Adiposity was assessed with body impedance analysis and body mass index, expressed as percentile rank. Mood and self-esteem were assessed with questionnaires. Estimates of food intake were highly reliable between two registered dietitians who independently estimated food intake. Boys ate more food than girls. A significant association between food intake and adiposity supported convergent validity. Non-significant correlations between food intake and depressed mood and self-esteem supported discriminant validity. When second servings were available, more food was selected and discarded, but mean food intake did not increase. Children who returned for second servings, however, ate more food when second servings were available, and a trend suggested that they also ate more food when second servings were not available. These findings support the reliability and validity of measuring children's food intake using digital photography and demonstrate its utility for studies of food intake and body weight.

Wise Mind project: a school-based environmental approach for preventing weight gain in children

OBJECTIVE

The Wise Mind pilot study compared the efficacy of an environmental approach for prevention of inappropriate weight gain in children with an active control condition that used an environmental approach for modifying expectancies related to the use of alcohol, tobacco, and drugs.

RESEARCH METHODS AND PROCEDURES

A total of 670 second to sixth grade students from four schools were enrolled in the study. The study spanned 2 academic years, and 586 students were available for evaluation at the end of the study. Two schools were randomly assigned to each treatment arm. The environmental approach for weight gain prevention focused on modification of eating habits and physical activity, and the active control group focused on modification of expectancies related to substance use.

RESULTS

Using an intention to treat design, the study found no differences in weight gain prevention between the two interventions. The weight gain prevention program was associated with reduction of total caloric intake, reduction of dietary fat intake, reduction of protein intake, and increased physical activity in comparison with the active control group and relative to baseline. These changes in food intake were attributed to changes in food selections that resulted from modification of school cafeteria menus and food preparation.

DISCUSSION

The Wise Mind school-based weight gain prevention program induced behavioral changes in healthy eating and physical activity but did not induce significant changes in body weight in comparison with the control arm. Recommendations for future research are provided.

Empirical evaluation of the ability to learn a calorie counting system and estimate portion size and food intake

The aim of this study was to determine if: (1) participants could learn the HMR Calorie System by testing if their use of the system was more accurate after training; and (2) estimated portion size and food intake improved with training. A secondary aim was to use PACE (photographic assessment of calorie estimation) to assess if participants learned the HMR system. The PACE consists of pictures of foods, the energy content of which is known. A within-subjects design was used to test the aims of this study. Participants were 44 overweight (25 <or= BMI < 30) adults who were randomly assigned to one of three calorie restriction groups or a weight maintenance group for 6 months. Participants attended weekly sessions and were trained to use the HMR system from weeks 5 to 8. Participants were provided with foods to test if they could effectively use the HMR system and accurately estimate portion size and the amount of food eaten. The PACE was also used to quantify accuracy at using the HMR system. Training resulted in more accurate estimation of food intake, use of the HMR system and estimated portion size when presented with food. Additionally, training resulted in significantly more accurate use of the HMR system when measured with PACE. It is concluded that people can learn the HMR Calorie System and improve the accuracy of portion size and food intake estimates. The PACE is a useful assessment tool to test if participants learn a calorie counting system.