Food/Non-Food Classification of Real-Life Egocentric Images in Low- and Middle-Income Countries Based on Image Tagging Features

Malnutrition, including both undernutrition and obesity, is a significant problem in low- and middle-income countries (LMICs). In order to study malnutrition and develop effective intervention strategies, it is crucial to evaluate nutritional status in LMICs at the individual, household, and community levels. In a multinational research project supported by the Bill & Melinda Gates Foundation, we have been using a wearable technology to conduct objective dietary assessment in sub-Saharan Africa. Our assessment includes multiple diet-related activities in urban and rural families, including food sources (e.g., shopping, harvesting, and gathering), preservation/storage, preparation, cooking, and consumption (e.g., portion size and nutrition analysis). Our wearable device ("eButton" worn on the chest) acquires real-life images automatically during wake hours at preset time intervals. The recorded images, in amounts of tens of thousands per day, are post-processed to obtain the information of interest. Although we expect future Artificial Intelligence (AI) technology to extract the information automatically, at present we utilize AI to separate the acquired images into two binary classes: images with (Class 1) and without (Class 0) edible items. As a result, researchers need only to study Class-1 images, reducing their workload significantly. In this paper, we present a composite machine learning method to perform this classification, meeting the specific challenges of high complexity and diversity in the real-world LMIC data. Our method consists of a deep neural network (DNN) and a shallow learning network (SLN) connected by a novel probabilistic network interface layer. After presenting the details of our method, an image dataset acquired from Ghana is utilized to train and evaluate the machine learning system. Our comparative experiment indicates that the new composite method performs better than the conventional deep learning method assessed by integrated measures of sensitivity, specificity, and burden index, as indicated by the Receiver Operating Characteristic (ROC) curve.

Usability Testing of a Sensor-Controlled Digital Game to Engage Older Adults with Heart Failure in Physical Activity and Weight Monitoring

BACKGROUND

Poor self-management of heart failure (HF) has contributed to poor health outcomes. Sensor-controlled digital games (SCDGs) integrates data from behavior-tracking sensors to trigger progress, rewards, content, and positive feedback in a digital game to motivate real-time behaviors.

OBJECTIVES

To assess the usability of an SCDG prototype over a week of game-playing among 10 older adults with HF in their homes.

METHODS

During initial play, participants' SCDG experiences were observed in their homes using a checklist based on the seven-item Serious Game User Evaluator (SeGUE) instrument. After a week of game-playing, participants completed a survey guided by the Intrinsic Motivation Inventory, to provide their perceptions of the SCDG's usability. Qualitative analysis via semistructured interview-derived themes on experiences playing the SCDG, perceptions regarding engaging with the SCDG, and any usability issues encountered.

RESULTS

Ten HF participants (50% women and 50% White) played the SCDG for an average of 6 out of 7 days. Nine found the SCDG to be interesting, satisfying, and easy to play. The average step count over a week was 4,117 steps (range: 967-9,892). Average adherence with weight monitoring was 5.9 days in a week. Qualitative analysis yielded outcomes regarding attitudes toward SCDG, and barriers and facilitators that influenced participants' engagement with the SCDG.

CONCLUSION

To the best of the authors' knowledge, this usability and feasibility study is the first to report an SCDG designed to improve HF self-management behaviors of older adults in their homes. Future research should consider several issues, such as user profiles, prior game-playing experiences, and network conditions most suitable for connected health interventions for older adults living in the community.

Personalizing Sensor-Controlled Digital Gaming to Self-Management Needs of Older Adults with Heart Failure: A Qualitative Study

Objectives: In older persons with heart failure (HF), an inability to self-manage their disease condition can result in poor health outcomes and quality of life. With the rise in smartphone use and digital game playing among older adults, digital tools such as sensor-controlled digital games (SCDGs) can offer accessible health-promoting tools that are enjoyable and easy to use. However, designing SCDGs that are compelling and aligned with their life values and self-management needs can be challenging. This article describes a qualitative study with older adults with HF who were recruited from a cardiac rehabilitation laboratory in central Texas to identify their perceptions and expectations regarding a SCDG for HF self-management. Materials and Methods: A low-fidelity prototype that demonstrated the features of a SCDG was used to obtain the participants' perceptions about the value of SCDGs for HF self-management with respect to content, customization, flexibility, and usability through qualitative interviews. Results: We interviewed 15 patients with HF (53% women; age range, 53-90 years; 60% white). The concept of SCDGs for HF self-management was highly acceptable (80%). Participants provided suggestions for game characters, progress in the game, and game notifications and incentives. Perceived benefits included helping users track their behaviors and establish routines, become informed on strategies to manage HF, and empower themselves to take charge of their health. Conclusions: The study's findings will guide personalization of SCDG development to motivate patient engagement in HF self-management behaviors.

USABILITY ASSESSMENT OF A SENSOR-CONTROLLED DIGITAL GAME FOR OLDER ADULTS WITH HEART FAILURE

The inability of older persons with heart failure (HF) to self-manage has contributed to poor health outcomes. Our team from nursing, digital game design, and mobile computing developed an innovative sensor-controlled digital game (SCDG) called ‘Heart Mountain’ to offer a portable, and enjoyable tool to facilitate engagement in HF self-management. We installed the SCDG application, which featured older adult game avatars on the participants’ smartphones. The SCDG utilized data from an activity tracker and weight scale to trigger game rewards, knowledge content and messages based on participants’ real-time behaviors. In this study we assessed the usability of a SCDG prototype with 10 HF older adults in Central Texas. Observations on the usability of the SCDG app by older adults were noted on a usability heuristics checklist. Acceptance and satisfaction were collected by an open-ended survey guided by Intrinsic Motivation Inventory after a week of playing the game. Participants (60% males, 60% white, ages 63-84) were able to play the game and use the devices after a training session that lasted for 15 minutes. We will present results on participants’ ease of use of the SCDG app, satisfaction with the knowledge content, quizzes and rewards features of the SCDG, and perceptions on acceptance and satisfaction with the SCDG for heart failure self-management. Our project will generate insights on designing digital gaming solutions that are acceptable to older adults and can be applied to improve self-management of chronic diseases like heart failure.

Excitation wavelength dependence of the fluorescence lifetime of anisole

Photo-physical models that describe the pressure- and temperature-dependent fluorescence quantum yield of organic fluorescence tracers rely on an accurate prediction of the initial excited-state population, collision-dependent relaxation processes, and state-dependent relaxation processes. In case the initial excited-state population distribution reached after the laser excitation equals on average the thermal distribution, the fluorescence quantum yield becomes pressure independent. This initial distribution critically depends on the temperature-dependent ground-state population before excitation as well as the excitation wavelength. The ability to predict this behavior is a critical check for the validity of the existing photophysical models. The dependence of the effective fluorescence lifetime of anisole on the excitation wavelength (256-270 nm) was investigated at temperatures between 325 and 525 K for pressures between 1 and 4 bar. For each temperature, a unique excitation wavelength was found where the fluorescence lifetime is pressure-independent. The comparison of the experimental results with the predictions based on the established photophysical step-ladder models revealed a systematic underestimation of the required excitation photon energies for direct excitation into the thermalized level. An improved modeling approach based on quantum chemistry calculations for implementing simulated excitation spectra and state-dependent transition probabilities overcomes these limitations. Our results show for the example of anisole that the fluorescence step-ladder models that exist for aromatic fluorescence tracers must be modified to correctly predict the effect of the excitation wavelength.

Role of Digital Games in Self-Management of Cardiovascular Diseases: A Scoping Review

OBJECTIVE

Examine research on the use of digital games to improve self-management (SM) behaviors in patients diagnosed with cardiovascular diagnoses of hypertension, coronary artery disease, heart failure, or myocardial infarction.

MATERIALS AND METHODS

For this scoping review, the CINAHL, PubMed, and Web of Science databases were searched for studies published from January 1, 2008 to December 20, 2017 using terms relevant to digital games and cardiovascular diseases (CVDs).

RESULTS

Eight articles met the inclusion/exclusion criteria, seven of which presented studies with participants 50 years or older. Five of the eight studies assessed physical activity. Only two studies included a control group. Digital games significantly improved exercise capacity and energy expenditure but did not affect quality of life, self-efficacy, anxiety, or depression. Digital games were found enjoyable by 79%-93% of participants, including those with lower education or age; however, barriers to game use included being tired or bored, lack of interest in digital games, poor perception of fitness through games, sensor limitations, conflicts with daily life routine, and preferences for group exercise. Average adherence ranged from 70% to 100% over 2 weeks to 6 months of study duration, with higher adherence rates in studies that included human contact through supervision or social support.

CONCLUSION

Paucity of studies about digital games for CVD SM behaviors precludes the need to undertake a full systematic review. Future studies examining digital games should include larger sample sizes, longer durations, game-design guided by behavioral change theoretical frameworks, and CVD SM behaviors in addition to physical activity behaviors.

Qualitative Analysis of Cognitive Interviews With School Children: A Web-Based Food Intake Questionnaire

Background

The use of computers to administer dietary assessment questionnaires has shown potential, particularly due to the variety of interactive features that can attract and sustain children’s attention. Cognitive interviews can help researchers to gain insights into how children understand and elaborate their response processes in this type of questionnaire.

Objective

To present the cognitive interview results of children who answered the WebCAAFE, a Web-based questionnaire, to obtain an in-depth understanding of children’s response processes.

Methods

Cognitive interviews were conducted with children (using a pretested interview script). Analyses were carried out using thematic analysis within a grounded theory framework of inductive coding.

Results

A total of 40 children participated in the study, and 4 themes were identified: (1) the meaning of words, (2) understanding instructions, (3) ways to resolve possible problems, and (4) suggestions for improving the questionnaire. Most children understood questions that assessed nutritional intake over the past 24 hours, although the structure of the questionnaire designed to facilitate recall of dietary intake was not always fully understood. Younger children (7 and 8 years old) had more difficulty relating the food images to mixed dishes and foods eaten with bread (eg, jam, cheese). Children were able to provide suggestions for improving future versions of the questionnaire.

Conclusions

More attention should be paid to children aged 8 years or below, as they had the greatest difficulty completing the WebCAAFE.

Obesity status transitions across the elementary years: use of Markov chain modelling

OBJECTIVE

The objective of this study was to assess overweight and obesity status transition probabilities using first-order Markov transition models applied to elementary school children.

METHOD

Complete longitudinal data across 11 assessments were available from 1494 elementary school children (from 7599 students in 41 out of 45 schools in a Southeast Texas school district) from kindergarten to the beginning of the fifth grade. Heights and weights were measured by trained school nurses using standard procedures at the beginning and end of each school year for the 11 consecutive assessments. To estimate the transition probabilities, first-order three-state (healthy weight, overweight and obese) Markov transition models were fit to the longitudinal weight status data of all assessment periods.

RESULTS

While there was a gradual shift to more children in the overweight or obese category over 5 years, children were most likely to stay in the same weight category as the previous assessment. A consistent seasonal difference in the probability of changing weight status category was seen, with a greater probability of becoming overweight and obese during the summer compared with the school year. The transition probabilities to obesity were higher among boys, Hispanic and non-Hispanic Black, and lower socioeconomic status children.

CONCLUSIONS

This study provides the first application of a Markov transition model to child weight status data. The transitions into the overweight and obese categories were small, but persistent, with smaller percentages transitioning out of overweight or obese. Early monitoring and summer intervention strategies are needed to prevent the slow, but relentless, transition into the overweight and obese categories.

Children's Cognitive and Affective Responses About a Narrative Versus a Non-Narrative Cartoon Designed for an Active Videogame

OBJECTIVE

This article presents the results of interviews conducted with children regarding their cognitive and affective responses toward a narrative and a non-narrative cartoon. The findings will be used to further explore the role of a narrative in motivating continued active videogame play.

MATERIALS AND METHODS

Twenty children (8-11 years old of mixed gender) watched two cartoons (narrative and non-narrative) and were subsequently interviewed. A thematic matrix was used to analyze the interviews.

RESULTS

The narrative cartoon (n = 11) was only slightly preferred compared with the non-narrative one (n = 9), with little difference among the participants. The theme categories identified during the analyses were plot, characters, and suggestions. The fight scenes were mentioned by the children as a likeable aspect of the narrative cartoon. In the non-narrative cartoon, the vast majority (n = 17) liked the information about physical activity that was provided. The children enjoyed the appearance and personalities of the characters in both cartoons. A discrepancy in the data about the fight scenes (narrative cartoon) and characters (both cartoons) was found among the female participants (i.e., some girls did not like the fight and thought the characters were too aggressive). However, most of the children wanted to see more action in the story, an increase in the number of fight scenes (narrative cartoon), or more information about exercise and examples of exercises they could do (non-narrative cartoon). They also suggested adding a game to the non-narrative cartoon, including more characters, and improving the animation in both cartoons.

CONCLUSIONS

The children preferred the narrative cartoon because of the story and the fight. Some gender differences were found, which further studies should investigate.

The IDEFICS intervention trial to prevent childhood obesity: design and study methods

INTRODUCTION

One of the major research dimensions of the Identification and prevention of Dietary- and lifestyle-induced health EFfects In Children and infantS (IDEFICS) study involved the development, implementation and evaluation of a setting-based community-oriented intervention programme for primary prevention of childhood obesity. In this supplement of Obesity Reviews, a compilation of key results of the IDEFICS intervention is packaged in a series of complementary papers.

OBJECTIVE

This paper describes the overall design and methods of the IDEFICS intervention in order to facilitate a comprehensive reading of the supplement. In addition, some 'best practice' examples are described.

RESULTS

The IDEFICS intervention trial was conducted to assess whether the IDEFICS intervention prevented obesity in young children aged 2 to 9.9 years. The study was a non-randomized, quasi-experimental trial with one intervention matched to one control region in each of eight participating countries. The intervention was designed following the intervention mapping framework, using a socio-ecological theoretical approach. The intervention was designed to address several key obesity-related behaviours in children, parents, schools and community actors; the primary outcome was the prevalence of overweight/obesity according to the IOTF criteria based on body mass index. The aim was to achieve a reduction of overweight/obesity prevalence in the intervention regions. The intervention was delivered in school and community settings over a 2-year period. Data were collected in the intervention and control cohort regions at baseline and 2 years later.

CONCLUSION

This paper offers an introductory framework for a comprehensive reading of this supplement on IDEFICS intervention key results.

Should the IDEFICS outcomes have been expected?

The Identification and prevention of Dietary- and lifestyle-induced health EFfects In Children and infantS (IDEFICS) study evaluated with a large sample a comprehensive carefully planned obesity prevention intervention targeting multiple levels of influence that were culturally adapted to the situations in eight European countries. Despite the great effort and attention to detail, the IDEFICS study did not achieve its targeted adiposity or behaviour change objectives. Should we be surprised that the IDEFICS trial did not have its intended effects? We think not, and would have been surprised if it did. Recent research has revealed the lack of consistent meaningful relationships between several apparently obesogenic behaviours and adiposity, weak or no relationships among behavioural change procedures, mediating variables and targeted behaviours and inadequate attention to moderating effects. Future obesity prevention interventions would benefit from a more thorough understanding of the complex relationships that have been hypothesized and the interrelationships with biological factors. While systems modelling has been proposed as providing the solution, important less complex identification of new constructs, new relationships and community interventions are still needed, both to find innovative solutions and to provide input into the systems models. We should question results from cross-sectional studies and be satisfied only with longitudinal or experimental tests of relationships.

An adaptive Hidden Markov model for activity recognition based on a wearable multi-sensor device

Human activity recognition is important in the study of personal health, wellness and lifestyle. In order to acquire human activity information from the personal space, many wearable multi-sensor devices have been developed. In this paper, a novel technique for automatic activity recognition based on multi-sensor data is presented. In order to utilize these data efficiently and overcome the big data problem, an offline adaptive-Hidden Markov Model (HMM) is proposed. A sensor selection scheme is implemented based on an improved Viterbi algorithm. A new method is proposed that incorporates personal experience into the HMM model as a priori information. Experiments are conducted using a personal wearable computer eButton consisting of multiple sensors. Our comparative study with the standard HMM and other alternative methods in processing the eButton data have shown that our method is more robust and efficient, providing a useful tool to evaluate human activity and lifestyle.

An exploratory study on a chest-worn computer for evaluation of diet, physical activity and lifestyle

Recently, wearable computers have become new members in the family of mobile electronic devices, adding new functions to those provided by smart-phones and tablets. As "always-on" miniature computers in the personal space, they will play increasing roles in the field of healthcare. In this work, we present our development of eButton, a wearable computer designed as a personalized, attractive, and convenient chest pin in a circular shape. It contains a powerful microprocessor, numerous electronic sensors, and wireless communication links. We describe its design concepts, electronic hardware, data processing algorithms, and its applications to the evaluation of diet, physical activity and lifestyle in the study of obesity and other chronic diseases.

Saliency-aware food image segmentation for personal dietary assessment using a wearable computer

Image-based dietary assessment has recently received much attention in the community of obesity research. In this assessment, foods in digital pictures are specified, and their portion sizes (volumes) are estimated. Although manual processing is currently the most utilized method, image processing holds much promise since it may eventually lead to automatic dietary assessment. In this paper we study the problem of segmenting food objects from images. This segmentation is difficult because of various food types, shapes and colors, different decorating patterns on food containers, and occlusions of food and non-food objects. We propose a novel method based on a saliency-aware active contour model (ACM) for automatic food segmentation from images acquired by a wearable camera. An integrated saliency estimation approach based on food location priors and visual attention features is designed to produce a salient map of possible food regions in the input image. Next, a geometric contour primitive is generated and fitted to the salient map by means of multi-resolution optimization with respect to a set of affine and elastic transformation parameters. The food regions are then extracted after contour fitting. Our experiments using 60 food images showed that the proposed method achieved significantly higher accuracy in food segmentation when compared to conventional segmentation methods.

Validation of a web-based questionnaire to assess the dietary intake of Brazilian children aged 7-10 years

BACKGROUND

The Food Intake and Physical Activity of School Children (CAAFE) comprises an online questionnaire to self-report diet and physical activity of Brazilian schoolchildren.

BACKGROUND

The present study aimed to assess the validity (matches, omissions and intrusions) and moderating factors of the CAAFE.

METHODS

Direct observation was made of foods consumed (five public schools) and child self-reporting on the CAAFE. Additional data included school grade, gender, body mass index, completion of food diary, socioeconomic status and access to computer. Data were analysed using regression.

RESULTS

In total, 602 children participated in the study [mean (SD) age 9.5 (1.24) years; 53.6% boys]. On average, there were 43% matches, 29% intrusions and 28% omissions. Matches doubled in third grade compared to the second grade (P = 0.004); matches almost tripled for afternoon snack compared to morning snack (P < 0.001); and matches were 69% higher for children with access to a computer at home (P < 0.01). Intrusions decreased by almost one-half in fifth compared to fourth grades (P = 0.004). Omissions declined significantly in the third and fourth grades but increased in the fifth grade. Omissions were 47% lower for children in the highest income and lower among children who completed the food diary. No differences were found for gender or body mass index.

CONCLUSIONS

Children older than 8 years old, who owned a computer and completed a food diary, performed better in the CAAFE. A high incidence of disagreement was found in relation to the schools and the type of meal. Overall matches (43%), intrusions (29%) and omissions (28%) indicate that further studies are required to improve the validity of the CAAFE.

Qualitative analysis of the contributions of nutritionists to the development of an online instrument for monitoring the food intake of schoolchildren

BACKGROUND

The Consumo Alimentar e Atividade Fisica de Escolares (CAAFE) questionnaire is an online research tool that has been developed to enable the self-report of physical activity and diet by Brazilian schoolchildren aged 7-10 years. Formative research was conducted with nutritionists during the development of the web-based questionnaire. The suggestions and insights obtained were used to design a tool to monitor schoolchildren's food consumption based on the concept of healthy and unhealthy food indicators. The present study aimed to report the focus group discussions conducted with nutritionists concerning the CAAFE questionnaire.

METHODS

Focus group discussions were conducted using a semi-structured questionnaire, and these were then analysed thematically.

RESULTS

Twenty-four nutritionists participated (four focus groups; average per group: six people); the majority (n = 22) had experience with 7-10-year-old children. Four themes emerged: (i) healthy and unhealthy food indicators; (ii) suggestions for the online instrument; (iii) potential applications; and (iv) challenges for its construction.

CONCLUSIONS

Comments made by nutritionists enabled the construction of an instrument that is able to answer questions related to food consumption in schools and at home.

Longitudinal associations between BMI, waist circumference, and cardiometabolic risk in US youth: monitoring implications

OBJECTIVE

This study examined whether change in body mass index (BMI) or waist circumference (WC) is associated with change in cardiometabolic risk factors and differences between cardiovascular disease specific and diabetes specific risk factors among adolescents. We also sought to examine any differences by gender or baseline body mass status.

DESIGN

The article is a longitudinal analysis of pre- and post-data collected in the HEALTHY trial. Participants were 4,603 ethnically diverse adolescents who provided complete data at 6th and 8th grade assessments.

METHODS

The main outcome measures were percent change in the following cardiometabolic risk factors: fasting triglycerides, systolic and diastolic blood pressure, high density lipoprotein cholesterol, and glucose as well as a clustered metabolic risk score. Main exposures were change in BMI or WC z-score. Models were run stratified by gender; secondary models were additionally stratified by baseline BMI group (normal, overweight, or obese).

RESULTS

Analysis showed that when cardiometabolic risk factors were treated as continuous variables, there was strong evidence (P < 0.001) that change in BMI z-score was associated with change in the majority of the cardiovascular risk factors, except fasting glucose and the combined risk factor score for both boys and girls. There was some evidence that change in WC z-score was associated with some cardiovascular risk factors, but change in WC z-score was consistently associated with changes in fasting glucose.

CONCLUSIONS

In conclusion, routine monitoring of BMI should be continued by health professionals, but additional information on disease risk may be provided by assessing WC.

Feasibility of an obesity intervention for paediatric primary care targeting parenting and children: Helping HAND

BACKGROUND

  The primary care setting offers the opportunity to reach children and parents to encourage healthy lifestyle behaviours, and improve weight status among children.

OBJECTIVE

  Test the feasibility of Helping HAND (Healthy Activity and Nutrition Directions), an obesity intervention for 5- to 8-year-old children in primary care clinics.

METHODS

  A randomized controlled pilot study of Helping HAND, a 6-month intervention, targeted children with body mass index 85-99%tile and their parents. Intervention group attended monthly sessions and self-selected child behaviours and parenting practices to change. Control group received regular paediatric care and was wait-listed for Helping HAND. Session completion, participant satisfaction, child anthropometrics, dietary intake, physical activity, TV viewing and behaviour-specific parenting practices were measured pre and post intervention.

RESULTS

  Forty parent-child dyads enrolled: 82.5% were Hispanic, 80% had a girl and 65% reported income ≤ $30, 000/year. There was 20% attrition from Helping HAND (attended <4/6 sessions). Families self-selected 4.35 (SD 1.75) behaviours to target during the 6-month programme and each of the seven behaviours was selected by 45-80% of the families. There were no between group differences in the child's body mass index z-score, dietary intake or physical activity post intervention. Intervention group viewed 14.9 (SE 2.3) h/week of TV post intervention versus control group 23.3 (SE 2.4) h/week (P < 0.05).

CONCLUSION

  Helping HAND is feasible, due to low attrition, good programme attendance, and clinically relevant improvements in some child and parenting behaviours.

Food Intake Recording Software System, version 4 (FIRSSt4): a self-completed 24-h dietary recall for children

The Food Intake Recording Software System, version 4 (firsst4), is a web-based 24-h dietary recall (24 hdr) self-administered by children based on the Automated Self-Administered 24-h recall (ASA24) (a self-administered 24 hdr for adults). The food choices in firsst4 are abbreviated to include only those reported by children in US national surveys; and detailed food probe questions are simplified to exclude those that children could not be expected to answer (e.g. questions regarding food preparation and added fats). ASA24 and firsst4 incorporate 10 000+ food images, with up to eight images per food, to assist in portion size estimation. We review the formative research conducted during the development of firsst4. When completed, firsst4 will be hosted and maintained for investigator use on the National Cancer Institute's ASA24 website.

How to engage children in self-administered dietary assessment programmes

Effectively assessing children's dietary intake is essential for understanding the complex relationships among dietary behaviours and obesity. Dietary assessment accuracy decreases when children are unable or unmotivated to complete accurate self-reports. Technology-based assessment instruments for children's self-report of diet can be enhanced in light of developments in media psychology and communication science. To motivate children to complete a dietary assessment, researchers could use animated, customisable agents; embed the assessment process into a video game; or add narratives to encourage self-reporting behaviour. To improve accuracy, the intake environment could be recreated virtually; training sessions could be interspersed to improve portion estimation; and implicit attitudinal measures could be incorporated as a control or to increase validity. Research is needed to evaluate possible methods of enhancing children's self-reporting motivation and accuracy. The main challenge remains how to engage children without biasing their reporting.

Relationship of fruit and vegetable intake with adiposity: a systematic review

Fruit and vegetable (FV) intake has been proposed to protect against obesity. The purpose of this paper was to assess the FV consumption to adiposity relationship. Twenty-three publications were included.

INCLUSION CRITERIA

longitudinal or experimental designs; FV intake tested in relation to adiposity; child, adolescent or adult participants; published in English-language peer-reviewed journals.

EXCLUSION CRITERIA

dietary pattern and cross-sectional designs; participants with health concerns. Experimental studies found increased FV consumption (in conjunction with other behaviours) contributed to reduced adiposity among overweight or obese adults, but no association was shown among children. Longitudinal studies among overweight adults found greater F and/or V consumption was associated with slower weight gain, but only half of child longitudinal studies found a significant inverse association. Limitations in methods prevented a thorough examination of the role of increased FV intake alone or mechanisms of effect. An inverse relationship between FV intake and adiposity among overweight adults appears weak; this relationship among children is unclear. Research needs to clarify the nature of, and mechanisms for, the effects of FV consumption on adiposity. Whether increases in FV intake in isolation from lower caloric intake or increased physical activity will result in declines or slower growth in adiposity remains unclear.

Serum levels of the adipokine fasting-induced adipose factor/angiopoietin-like protein 4 depend on renal function

Fasting-induced adipose factor/angiopoietin-like protein 4 (FIAF/Angptl4) was recently introduced as a novel adipokine influencing glucose and lipid homeostasis. In the current study, we quantified circulating FIAF/Angtl4 levels in patients on chronic hemodialysis (CD) as compared to controls with a glomerular filtration rate above 50 ml/min. FIAF/Angptl4 was determined by ELISA in control (n=60) and CD (n=60) patients and correlated to clinical and biochemical measures of renal function, glucose and lipid metabolism, as well as inflammation, in both groups. Median serum FIAF/Angptl4 levels were more than 5-fold higher in CD patients (48.3 μg/l) as compared to control subjects (8.4 μg/l) (p<0.001). Furthermore, serum creatinine independently predicted FIAF/Angptl4 concentrations in multiple regression analyses in control subjects (p<0.01). In CD patients, C-reactive protein was independently and positively associated with circulating FIAF/Angptl4 (p<0.01). Taken together, we show that serum FIAF/Angptl4 levels are significantly increased in end-stage renal disease and independently associated with markers of renal function in control subjects.

Presence of diabetes risk factors in a large U.S. eighth-grade cohort

OBJECTIVE

The study was conducted in 12 middle schools to determine the prevalence of diabetes, pre-diabetes, and diabetes risk factors in eighth-grade students who were predominantly minority and evaluate the feasibility of collecting physical and laboratory data in schools.

RESEARCH DESIGN AND METHODS

Anthropometric measurements and fasting and 2-h post-glucose load blood draws were obtained from approximately 1,740 eighth-grade students.

RESULTS

Mean recruitment rate was 50% per school, 49% had BMI > or = 85th percentile, 40.5% had fasting glucose > or = 100 mg/dl, 0.4% had fasting glucose > or = 126 mg/dl, and 2.0% had 2-h glucose > or = 140 mg/dl and 0.1% > or = 200 mg/dl. Mean fasting insulin value was 30.1 microU/ml, 36.2% had fasting insulin > or = 30 microU/ml, and 2-h mean insulin was 102.1 microU/ml. Fasting and 2-h glucose and insulin values increased across BMI percentiles, and fasting glucose was highest in Hispanic and Native American students.

CONCLUSIONS

There was a high prevalence of risk factors for diabetes, including impaired fasting glucose (> or =100 mg/dl), hyperinsulinism suggestive of insulin resistance (fasting insulin > or = 30 microU/ml), and BMI > or = 85th percentile. These data suggest that middle schools are appropriate targets for population-based efforts to decrease overweight and diabetes risk.

BMI from 3–6 y of age is predicted by TV viewing and physical activity, not diet

OBJECTIVE

To investigate whether, diet, physical activity, sedentary behavior or television (TV) viewing predicted body mass index (BMI) among 3-7-y-old children.

DESIGN

A triethnic cohort of 3-4-y-old children was followed for 3 y from 1986 to 1989.

MEASUREMENTS

BMI was assessed at the beginning and end of each measurement year. Heart rate monitoring and observation were used to assess physical activity. Diet (calories, % calories from fat and carbohydrate), sedentary behavior and TV viewing were assessed by direct observation in each year. A repeated measures regression analysis with year as a factor and BMI at the end of each year as dependent variables was run. Nonsignificant variables were removed in a stepwise backward deletion process and significant interactions graphed.

RESULTS

The interactions between minutes of TV viewing per hour and study year and minutes of physical activity per hour and study year were significant (P<0.05). There were also significant main effects for TV viewing, physical activity and BMI from the beginning of the study. The model accounted for 65% of the variance in BMI across the three study years. Plotting the significant interactions demonstrated that physical activity was positively associated with BMI in year 1, and negatively associated in years 2 and 3 with a stronger negative relationship in year 3 than 2. TV viewing became positively associated with BMI during the third study year.

CONCLUSION

Physical activity and TV viewing were the only significant predictors (other than baseline BMI) of BMI among a triethnic cohort of 3-4-y-old children followed for 3 y with both physical activity (negatively associated) and TV viewing (positively associated) becoming stronger predictors as the children aged. It appears that 6 or 7 y is a critical age when TV viewing and physical activity may affect BMI. Therefore, focusing on reducing time spent watching television and increasing time spent in physical activity may be successful means of preventing obesity among this age group.

Eating patterns, dietary quality and obesity

Obesity among children has reached epidemic proportions. Today, an estimated one in four children in the United States is overweight. while 11% arc obese. Children who are overweight tend to remain so up to 20 years of age; in general, they have a 1.5- to twofold higher risk for becoming overweight as adults. The prevalence of overweight has increased approximately twofold in the 20-year period from 1974 to 1994, with the largest increases observed among 19- to 24-year-olds. The annual increases in weight and obesity that occurred from 1983 to 1994 were 50% higher than those from 1973 to 1982. Overweight youth are 2.4 times as likely to have a high serum total cholesterol level, and 43.5 times as likely to have three cardiovascular risk factors. Although the total energy intake of children has remained the same, and the macronutrient density of the diet has changed, the percentage of energy from fat has decreased, while that from carbohydrates and protein has increased. Children have been consuming lower amounts of fats/oils, vegetables/soups, breads/grains, mixed meats, desserts, candy, and eggs. and increasing amounts of fruits/fruit juices, beverages. poultry, snacks, condiments, and cheese. Changes in specific eating patterns may explain the increase in adiposity among children; e.g., increases have occurred in the number of meals eaten at restaurants, food availability, portion sizes, snacking and meal-skipping. Successful prevention and treatment of obesity in childhood could reduce the adult incidence of cardiovascular disease. Because substantial weight loss is difficult to maintain, the prevention of obesity by promoting healthier lifestyles should be one of our highest priorities in the new millennium.

A motivational interviewing intervention to increase fruit and vegetable intake through Black churches: results of the Eat for Life trial

OBJECTIVES

This study reports on Eat for Life, a multicomponent intervention to increase fruit and vegetable consumption among African Americans that was delivered through Black churches.

METHODS

Fourteen churches were randomly assigned to 3 treatment conditions: (1) comparison, (2) self-help intervention with 1 telephone cue call, and (3) self-help with 1 cue call and 3 counseling calls. The telephone counseling in group 3 was based on motivational interviewing. The primary outcome, assessed at baseline and 1-year follow-up, was fruit and vegetable intake as assessed by 3 food frequency questionnaires.

RESULTS

Change in fruit and vegetable intake was significantly greater in the motivational interviewing group than in the comparison and self-help groups. The net difference between the motivational interviewing and comparison groups was 1.38, 1.03, and 1.21 servings of fruits and vegetables per day for the 2-item, 7-item, and 36-item food frequency questionnaires, respectively. The net difference between the motivational interviewing and self-help groups was 1.14, 1.10, and 0.97 servings for the 2-item, 7-item, and 36-item food frequency questionnaires, respectively.

CONCLUSIONS

Motivational interviewing appears to be a promising strategy for modifying dietary behavior, and Black churches are an excellent setting to implement and evaluate health promotion programs.

Family and child-care provider influences on preschool children's fruit, juice, and vegetable consumption

Children's intakes of fruit, juice, and vegetables (FJV) do not meet the recommended minimum of five daily servings, placing them at increased risk for development of cancer and other diseases. Because children's food preferences and practices are initiated early in life (e.g., 2-5 years of age), early dietary intervention programs may have immediate nutritional benefit, as well as reduce chronic disease risk when learned healthful habits and preferences are carried into adulthood. Families and child-care settings are important social environments within which food-related behaviors among young children are developed. FJV preferences, the primary predictor of FJV consumption in children, are influenced by availability, variety, and repeated exposure. Caregivers (parents and child-care providers) can influence children's eating practices by controlling availability and accessibility of foods, meal structure, food modeling, food socialization practices, and food-related parenting style. Much remains to be learned about how these influences and practices affect the development of FJV preferences and consumption early in life.

A 7-item versus 31-item food frequency questionnaire for measuring fruit, juice, and vegetable intake among a predominantly African-American population

OBJECTIVE

This study sought to determine which of 2 fruit and vegetable food frequency questionnaires (FFQs) most closely approximated intake measured by the average of four 24-hour dietary recalls.

DESIGN

Participants completed either a 31-item FFQ (n = 70) or 7-item FFQ (n = 76) on 2 occasions approximately 2 weeks apart. During the interval between FFQs1 participants provided four 24-hour dietary recalls via telephone interview.

SUBJECTS/SETTING

Participants were 146 persons with food preparation responsibilities in families of students in grades 3 through 5. Respondents were predominantly African-American women in Atlanta, Ga.

STATISTICAL ANALYSIS

Pearson correlation coefficients of log-transformed values estimated the reliability of each FFQ and compared FFQ estimates to reference values. The intraclass correlation coefficient evaluated consistency across 24-hour recalls.

RESULTS

The first FFQs overestimated intake approximately twofold. The 31-item FFQ estimates exceeded 7-item FFQ estimates by approximately 30% . Correlations with recall estimates were high for the 7-item FFQ and moderate to low for the 31-item FFQ. The second FFQ estimates were more highly correlated to reference values. From the first to the second administration, 7-item FFQ estimates dropped from 5.2 to 2.7 servings, and 31-item FFQ estimates dropped from 6.7 to 3.5 servings. Neither FFQ produced highly reliable estimates.

CONCLUSIONS

Mean total fruit and vegetable consumption was closer to reference estimates for the first 7-item FFQ and the second 31-item FFQ. The 7-item FFQ correlated more highly with reference estimates than did the 31-item FFQ. Therefore, we conclude that for African-American adults, a 1-time-administered FFQ using 7 broad food categories correlates more highly with reference values than a FFQ using 31 individual fruit and vegetable items.

Ecological and socioeconomic correlates of fruit, juice, and vegetable consumption among African-American boys

BACKGROUND

Investigators have reported that the availability of foods in local grocery stores correlated with consumption when using large geopolitical units of analysis, e.g., zip codes. Associations across smaller geopolitical units, e.g., census tracts, have not been tested, nor has this work focused on restaurant availability, child consumption, or specific ethnic groups.

METHODS

This study examined whether median family income and fruit, juice, and vegetable (FJV) availability in grocery stores, restaurants, and homes in 11 census tracts correlated with FJV consumption among 11- to 14-year-old African-American Boy Scouts. FJV consumption was measured in 90 scouts using two 24-h food recalls. Instruments were developed to measure the availability of FJV at area grocery stores, restaurants, and homes where troop members resided.

RESULTS

Median household income (from 1990 census) was significantly correlated with restaurant fruit availability. Significant correlations were found between restaurant juice and vegetable availability and Boy Scout reported consumption of juice and vegetables.

CONCLUSION

Census tract may be a useful unit when studying restaurant, but not grocery store, FJV availability. Within a census tract, restaurant FJV availability may be a significant target for community intervention and process evaluation.

Using goal setting as a strategy for dietary behavior change

Recent reviews have noted that behavioral theory-based nutrition education programs are more successful at achieving food behavior change than knowledge-based programs and that a clear understanding of the mechanisms of behavior change procedures enable dietetics professionals to more effectively promote change. Successful dietary behavior change programs target 1 or more of the personal, behavioral, or environmental factors that influence the behavior of interest and apply theory-based strategies to influence or change those factors. Goal setting is a strategy that is frequently used to help people change. A 4-step goal-setting process has been identified: recognizing a need for change; establishing a goal; adopting a goal-directed activity and self-monitoring it; and self-rewarding goal attainment. The applications of goal setting in dietary interventions for adults and children are reviewed here. Because interventions using goal setting appear to promote dietary change, dietitians should consider incorporating the goal-setting strategies to enhance the behavior change process in nutrition education programs.

Child-reported family and peer influences on fruit, juice and vegetable consumption: reliability and validity of measures

Family, peers and other environmental factors are likely to influence children's dietary behavior but few measures of these phenomena exist. Questionnaires to measure family and peer influences on children's fruit, juice and vegetable (FJV) consumption were developed and pilot tested with an ethnically diverse group of Grade 4-6 children. Principal components analyses revealed subscales with acceptable internal consistencies that measured parent and peer FJV modeling, normative beliefs, normative expectations, perceived peer FJV norms, supportive and permissive parenting practices, food rules, permissive eating, and child food preparation. Internal consistencies were adequate to high, but test-re-test correlations often were low. Children also completed questionnaires on FJV availability and accessibility in the home, and food records for 2 days in the classroom. Parental modeling, peer normative beliefs and FV availability were significantly correlated with FJV consumption. Further research with these scales is warranted.

Risk factor distribution among sociodemographically diverse African American adults

Because African Americans tend to have lower socioeconomic status (SES) than whites and numerous health indicators are related to SES variables, it is important when examining between-group differences in health indices to account for SES differences. This study examined the effects of income and education on several biologic and behavioral risk factors in a sample of sociodemographically diverse African American adults. Approximately 1,000 African American adults (aged 18-87) were recruited from 14 churches with predominantly black membership to participate in a nutrition education intervention. Demographics, height, weight, blood pressure, self-reported cigarette and alcohol use, self-reported diet by food frequency questionnaire, serum carotenoids, serum total cholesterol, and nutrition knowledge were assessed. The association of these risk factors were examined by four levels of education and income. For men, body mass index, blood pressure, total cholesterol, daily intake of fruits and vegetables, serum carotenoids, heavy alcohol use, or exercise were not associated significantly with income or education using analysis of variance (ANOVA). Past month alcohol use and nutrition knowledge were associated positively with education, but not income. For women, body mass index and smoking were associated inversely with income, but not with education. Blood pressure, total cholesterol, intake of fruits and vegetables, heavy alcohol use, and exercise were not associated with either income or education using ANOVA. Serum carotenoids, any 30-day alcohol use, and nutrition knowledge were associated positively with both income and education. Results using linear regression generally were similar for men and women, although a few more variables were associated significantly with SES compared to ANOVA analyses. Several health indicators that have been associated with socioeconomic variables in whites were not associated or only weakly associated in this diverse sample of African Americans. One interpretation of these findings is that SES factors may function differently among blacks and whites.

Effect of a la carte and snack bar foods at school on children's lunchtime intake of fruits and vegetables

OBJECTIVES

To compare lunch fruit, juice, and vegetable (FJV) intake of fourth-grade students who receive only National School Lunch Program meals and fifth-grade students who also have access to a school snack bar and to compare FJV intake by meal source among fifth-grade students.

DESIGN

Cross-sectional study: students completed FJV preference questionnaires and 5 days of lunch food records in classrooms.

SUBJECTS/SETTING

312 fourth- and 282 fifth-grade students in south Texas.

MAIN OUTCOME MEASURES

Mean FJV consumption.

STATISTICAL ANALYSES PERFORMED

Descriptive statistics, correlation analyses, analysis of variance, analysis of covariance.

RESULTS

Fourth-grade students (n = 312) consumed significantly more fruits, juices, and vegetables (0.80 serving) than fifth-grade students (n = 282) (0.60 serving). Students whose parents reported a high school education or less consumed more regular and total vegetables than students whose parents reported some college or higher education. There were no interaction effects among gender, grade, ethnic, or family education groups. Fifth-grade students who ate only snack bar meals consumed significantly less total fruits, juices, and vegetables (0.40 serving) than fifth-grade students who ate school lunch meals (0.82 serving). Controlling for FJV preferences did not change the main effect for grade level in the FJV consumption models.

APPLICATIONS/CONCLUSIONS

FJV consumption during school lunch is low. School foodservice staff should identify FJV items that middle school students prefer and increase availability of those items in middle school cafeterias and snack bars.

Validation of three food frequency questionnaires and 24-hour recalls with serum carotenoid levels in a sample of African-American adults

The validity of self-reported fruit and vegetable intake in minority populations has not been adequately established. In this study, the authors examined the association of three food frequency questionnaires (FFQs) and 24-hour dietary recalls with serum carotenoid levels. Approximately 1,000 African-American adults recruited from 15 churches in Atlanta, Georgia (1997-1998) completed three fruit and vegetable FFQs: a seven-item instrument assessing intake during the past month; a two-item measure assessing usual intake; and a 36-item measure adapted from the Health Habits and History Questionnaire. A total of 414 participants received a 24-hour recall by telephone, and 105 of them received two additional recalls. Serum levels of lycopene, lutein, cryptoxanthin, alpha-carotene, and beta-carotene were assessed in 813 participants and used as the validity criterion. The correlations of fruit and vegetable servings with specific and total serum carotenoid levels were generally higher for the 36-item FFQ than for the two-item and seven-item instruments. The strongest correlation of fruit and vegetable servings with total carotenoid levels was observed for the three recalls (r = 0.42), with the 36-item FFQ and the single 24-hour recall yielding comparable correlations (r = 0.35 and r = 0.37, respectively). The validity of the 36-item fruit and vegetable FFQ was generally as strong as the validity of both 1 and 3 days of recalls. Given the lower cost and time needed for administration relative to recalls, it appears that the 36-item FFQ has merit for evaluating fruit and vegetable health interventions.

Social-environmental influences on children's diets: results from focus groups with African-, Euro- and Mexican-American children and their parents

Children's fruit, juice and vegetable (FJV) and fat intakes do not meet recommended guidelines. Since personal factors account for only a small percentage of the variability in children's FJV consumption, social and environmental influences were explored via focus group discussions with Grade 4-6 African-, Euro- and Mexican-American students and parents. Questions included the effects of social influences, availability and accessibility on children's FJV and low-fat food choices. Few ethnic differences were noted. A variety of low-fat items and fresh FJV (not cut-up) were available at home; older children were expected to prepare their own. Eating out occurred at least twice a week; FJV were not usual restaurant choices. Students reported some modeling by parents (more mothers) and friends (usually at lunch). Negative peer responses for eating vegetables were reported. Parents were concerned with children eating too much junk food and not enough FJV, recognized the outside influences their children received about food, and reported several methods to encourage children to eat FJV. Recommendations for future interventions are proposed.

GO GIRLS!: results from a nutrition and physical activity program for low-income, overweight African American adolescent females

This article describes the development, implementation, and results of an intervention designed for inner-city, overweight African American adolescent women. Fifty-seven participants were recruited from four public housing developments. Participants were administered physiologic, dietary, and cognitive assessments at baseline and immediately postintervention. Each session comprised three elements: (1) an educational/behavioral activity, (2) 30 to 60 minutes of physical activity, and (3) preparation and tasting of low-fat meals. In the absence of a control group, results were compared for high and low attenders, the former defined as attending at least 50% of the sessions. High attenders (n = 26) showed more favorable 6-month posttest values for most outcomes compared with low attenders (n = 31). These effects achieved statistical significance for nutrition knowledge, low-fat practices, perceived changes in low-fat practices, and social support.

Socioenvironmental influences on children's fruit, juice and vegetable consumption as reported by parents: reliability and validity of measures

OBJECTIVE

To pilot test theory-based questionnaires to measure socioenvironmental influences on children's fruit, juice and vegetable (FJV) consumption as reported by parents.

DESIGN

Cross-sectional.

SETTING

Parents of fourth to sixth grade students completed socioenvironmental questionnaires. The students completed food records (FRs) for 2 days in the classroom.

SUBJECTS

Interviews were completed by 109 parents (17% African-American, 32% Hispanic-American and 51 Euro-American).

RESULTS

Student mean daily FJV intake was 2.1 servings. Principal components analyses revealed subscales measuring positive and negative parenting practices; self-efficacy for modelling and planning/encouraging FJV consumption, and making FJV available; encouraging, consequences and discouraging food socialization practices; negative home, cost and canned/frozen food barriers; meal planning; child shopping; mother food preparation; and child lunch and dinner FJV preparation practices. Internal consistencies were adequate to high. Negative parent practices and negative home FJV barriers were significantly negatively correlated with child FJV consumption variables. Planning/encouraging self-efficacy was positively associated with fruit consumption, and child dinner FJV preparation was significantly negatively correlated with child juice consumption.

CONCLUSIONS

These questionnaires may provide important insights about the relationship between parent-reported socioenvironmental influences and children's FJV consumption. Future work should test these questionnaires with larger groups of parents and youths, with more reliable estimates of usual FJV intake, e.g. 7-day food records, to obtain a detailed understanding of how parents influence what children eat. Tests of models of relationships among these variables are warranted, but should control for possible confounding variables, e.g. socioeconomic status, gender of the child, etc.