Assessment of diet and physical activity of brazilian schoolchildren: usability testing of a web-based questionnaire

Temporal trend of food consumption markers, breakfast consumption and association with overweight/obesity in schoolchildren aged 7 to 10 years between 2007 and 2019

Obesity has a multifactorial origin. Among the behavioural risk factors, excessive consumption of unhealthy foods, skipping breakfast and reduced physical activity stand out. The main objective of this article was to identify trends in dietary habits and their association with overweight/obesity over a 12-year period in schoolchildren aged 7 to 10 years in Florianópolis, southern Brazil. A cross-sectional panel analysis study, using anthropometric, sociodemographic, physical activity and food consumption data of schoolchildren aged 7 to 10 years, collected in three waves of the Study of Prevalence of Obesity in Children and Adolescents (EPOCA), carried out during the years 2007, 2012/2013 and 2018/2019, was performed. To analyse the trend in dietary variables over the years, the 95% CIs were compared with the non-overlap of intervals indicating statistical significance. Multiple logistic regression analysis was performed to test the association of weight status with dietary markers. The prevalence of overweight/obesity was 34.4%, 37.2% and 34.2% in 2007, 2012/2013 and 2018/2019, respectively, and there were no statistically significant differences among waves. There was a progressive and significant reduction in the consumption of soft drinks and sweets and in eating breakfast by schoolchildren, from 2007 to 2019. Breakfast consumption was inversely associated with the chance of overweight/obesity (OR 0.74, 95% CI 0.59-0.93), and female students were less likely to have overweight/obesity when compared to boys (OR 0.70, 95% CI 0.61-0.81). The reduction in the consumption of soft drinks and sweets over the years might be caused by efforts in public policies that intended to reduce the consumption of unhealthy foods among schoolchildren. The progressive and significant reduction in having breakfast should be better elucidated in future studies, to minimise the potential impact of this practice on schoolchildren's bodyweight.

Development and application of the Meal and Snack Assessment (MESA) quality scale for children and adolescents using item response theory

BACKGROUND

Meals differ in terms of food items and nutritional quality. The aim of the present study was to propose a scale to measure the meals quality of schoolchildren according to food processing degree, perform a preliminary evaluation of the scale's validity and reliability and apply the scale to a representative sample of schoolchildren in a city in southern Brazil.

METHODS

A methodological study based on the generalized graded unfolding model (GGUM) of item response theory (IRT) with analysis of secondary data was carried out in 6,399 schoolchildren of 6-15y-old attending 2nd to 5th grades of public elementary schools in Florianópolis, Brazil, in 2013-2015 who answered the validated Food Intake and Physical Activities of Schoolchildren (WebCAAFE) questionnaire. Meal quality was the latent trait. The steps for the development of the scale included: latent trait definition; item generation; dimensionality analysis; estimation of item parameters; scale levels definition; assessment of validity and reliability; and assessment of the meal quality of a subsample of schoolchildren aged 7 to 12 years (n = 6,372).

RESULTS

Eleven out of eighteen items had adequate parameters, without differential item functioning for sex or age. Meal quality was categorized into three levels: healthy, mixed, and unhealthy. Higher scores indicate a greater prevalence of ultra-processed foods in daily meals. Most schoolchildren had mixed (40.6%) and unhealthy (41%) meal patterns.

CONCLUSIONS

IRT analysis allowed the development of the scale, which measures the quality of meals and snacks based on the degree of food processing. At all snack times, there was a higher frequency of ultra-processed foods consumption, therefore foods consumed as snacks are a potential focus for nutritional interventions.

Use of Digital Tools for the Assessment of Food Consumption in Brazil: A Scoping Review

This is a scoping review on mapping the use of digital tools to assess food consumption in Brazil. Searches were carried out in nine electronic databases (Medline, Lilacs, Scopus, Embase, Web of Science, Science Direct, Ovid, Free Medical Journal and Crossref) to select studies published from October 2020 to December 2023. This review identified forty-eight digital tools in the 94 publications analyzed, the most frequent being web-based technologies (60%) and mobile devices (40%). Among these studies, 55% (n = 52) adopted a population-based approach, while 45% (n = 42) focused on specific regions. The predominant study design observed was cross-sectional (n = 63). A notable trend observed was the increasing frequency of validation studies in recent years. Although the use of digital tools in the assessment of food consumption in Brazil has grown in recent years, studies did not describe the process of creating and validating the tools, which would contribute to the improvement of data quality. Investments that allow the expansion of the use of the internet and mobile devices; the improvement of digital literacy; and the development of open-access tools, especially in the North and Northeast regions, are challenges that require a concerted effort towards providing equal opportunities, fostering encouragement, and delving deeper into the potential of digital tools within studies pertaining to food consumption in Brazil.

Food patterns associated with overweight in 7-11-year old children: machine-learning approach

Longitudinal study, whose objective was to present a better strategy and statistical methods, and demonstrate its use with the data across the 2013-2015 period in schoolchildren aged 7 to 11 years, covered with the same food questionnaire (WebCAAFE) survey in Florianopolis, southern Brazil. Six meals/snacks and 32 foods/beverages yielded 192 possible combinations denominated meal/snack-Specific Food/beverage item (MSFIs). LASSO algorithm (LASSO-logistic regression) was used to determine the MSFIs predictive of overweight/obesity, and then binary (logistic) regression was used to further analyze a subset of these variables. Late breakfast, lunch and dinner were all associated with increased overweight/obesity risk, as was an anticipated lunch. Time-of-day or meal-tagged food/beverage intake result in large number of variables whose predictive patterns regarding weight status can be analyzed by machine learning such as LASSO, which in turn may identify the patterns not amenable to other popular statistical methods such as binary logistic regression.

Association between Sleep Timing, Being Overweight and Meal and Snack Consumption in Children and Adolescents in Southern Brazil

Sleep timing is one of the dimensions of sleep that refers to the time of day when sleep occurs. It has been included in sleep-related research because of the potential associations between being overweight and the consumption of meals and snacks. This cross-sectional study aimed to investigate associations between sleep timing, meal and snack consumption and weight status in 1333 schoolchildren aged 7-14 years. The midpoint of sleep was used as a sleep timing measure obtained by the midpoint between bedtime and wake-up time, classified as Early, Intermediate, and Late. Schoolchildren in the Early group were less likely to be overweight (OR: 0.83, 95% CI 0.69; 0.99), and had higher odds of mid-morning snack consumption (OR: 1.95, 95% CI 1.56; 2.44) and lower probability to consume an evening snack (OR: 0.75, 95% CI 0.59; 0.94) compared with the Intermediate group. The Late group had lower odds of mid-morning snack consumption (OR: 0.67, 95% CI 0.55, 0.80) than the Intermediate group. The consumption of mid-morning and evening snacks was associated with the Early and Late midpoints of sleep. These results suggest that bedtime and wake-up time are relevant to consuming meals and snacks and may also be related to a greater probability of being overweight in children and adolescents.

Technological tools for assessing children's food intake: a scoping review

Technological innovations can standardise and minimise reporting errors in dietary assessment. This scoping review aimed to summarise the characteristics of technological tools used to assess children's food intake. The review followed the Joanna Briggs Institute's manual. The main inclusion criterion was studied that assessed the dietary intake of children 0-9 years of age using technology. We also considered articles on validation and calibration of technologies. We retrieved 15 119 studies and 279 articles were read in full, after which we selected 93 works that met the eligibility criteria. Forty-six technologies were identified, 37 % of which had been developed in Europe and 32⋅6 % in North America; 65⋅2 % were self-administered; 27 % were used exclusively at home; 37 % involved web-based software and more than 80 % were in children over 6 years of age. 24HR was the most widely used traditional method in the technologies (56⋅5 %), and 47⋅8 % of the tools were validated. The review summarised helpful information for studies on using existing tools or that intend to develop or validate tools with various innovations. It focused on places with a shortage of such technologies.

How Brazilian Schoolchildren Identify, Classify, and Label Foods and Beverages-A Card Sorting Methodology

This study examined how Brazilian schoolchildren identified, classified, and labeled foods and beverages. Semi-structured interviews were conducted with 133 schoolchildren aged 7 to 10 years old from a public school located in southern Brazil in 2015. A set of cards with pictures of 32 food and beverage items from the web-based Food Intake and Physical Activity of Schoolchildren tool (Web-CAAFE) were used. Participants identified each item, formed groups for them based on similarity, and assigned labels for those groups. Student's t-tests and analysis of variance (ANOVA) tests were used to verify the mean difference between the groups of items. K-means cluster analysis was applied to identify similar clusters. Schoolchildren made an average of 9.1 piles of foods and beverages that they thought were similar (±2.4) with 3.0 cards (±1.8) each. Five groups were identified: meats, snacks and pasta, sweets, milk and dairy products, and fruits and vegetables. The most frequently used nomenclature for labeling groups was taxonomic-professional (47.4%), followed by the specific food item name (16.4%), do not know/not sure (13.3%), and evaluative (health perception) (8.8%). The taxonomic-professional category could be applied to promote improvements in the identification process of food and beverage items by children in self-reported computerized dietary questionnaires.

Methodological aspects and characteristics of participants in the study on the prevalence of obesity in children and adolescents in Florianópolis, Southern Brazil, 2018-2019: EPOCA study

PURPOSE

To describe the methodological aspects and characteristics of the participants of the EPOCA survey.

METHODS

The study was conducted with schoolchildren aged between seven to 14 years old from 30 schools in Florianópolis, Southern Brazil. Body mass, height, girths, and skinfold thicknesses were measured. Food consumption and physical activity from the previous day were self-reported using the validated Web-CAAFE questionnaire. Adolescents completed a specific questionnaire about physical activity, meal consumption, and weight control behaviors. Parents/guardians responded to a sociodemographic and habits questionnaire.

RESULTS

A total of 1671 schoolchildren participated in the study (response rate: 27.2%). About 63% of schoolchildren were enrolled in public schools. Most studied in the morning shift (54.2%), were female (53.1%) and aged between seven and 10 years (58.1%). The prevalence of overweight was 33.7% and obesity was 11.3%.

CONCLUSIONS

The data obtained will allow us to assess the trend in the prevalence of overweight and obesity and associated factors when compared to other surveys performed. Descriptions of the logistics and protocols can help in the development and improvement of similar studies. It is hoped that the results of EPOCA 2018/2019 may help in the design of obesity prevention policies and programs for this population.

Validación de un cuestionario web sobre actividad física para niños y adolescentes

El objetivo del estudio fue llevar a cabo la validez concurrente del cuestionario WebCas para evaluar la actividad física (AF) en 140 estudiantes (10 a 16 años) divididos en cuatro grupos, instruidos para usar un acelerómetro y contestar el cuestionario WebCas diariamente, resultó en 213 días de monitoreo de AF. Los análisis estadísticos se realizaron utilizando la prueba U de Mann-Whitney, gráficos de dispersión (Bland y Altmann) y coeficientes de correlación. La correlación entre las mediciones de AF (WebCas) en comparación con las mediciones de acelerometria (un día) mostró correlación de baja intensidad (r = 0.22; p <0.001), moderado intensidad (r = 0,48; p <0,04), promedio de los tres días. Se observó mayor correlación para el promedio de AF de los 5 días (r = 0,67; p <0,01). El cuestionario WebCas presentó indicadores de validez satisfactorios.

Is breakfast consumption among Brazilian schoolchildren associated with an ultra-processed food dietary pattern?

Omission of breakfast starts at school age and can be explained as a reflection of the independent behaviour acquired in this phase of life. Breakfast has been investigated for its association with healthier diet quality, but few studies have investigated this relationship in schoolchildren aged 7 to 13 years. The objective of this study was to assess breakfast consumption in schoolchildren aged 7 to 13 years and to examine associations with dietary patterns (DPs). It was a cross-sectional study carried out in 2017 with 1069 students in Florianopolis, southern Brazil. Previous-day food consumption, physical activity and screen activities were self-reported. Factor analysis was used to identify DPs. Associations between breakfast consumption and overall DPs were evaluated using multivariate linear regression. Breakfast consumption was reported by 85% of the children, with the highest proportion observed among students on the afternoon school shift. Five DPs were identified explaining 41% of the total variance in daily food consumption: Ultra-processed, Mixed, Traditional Brazilian Lunch, Healthy + Sweets and Traditional Brazilian Breakfast. Breakfast consumption was directly associated with a Traditional Brazilian Breakfast DP (β = 0.335; 95% CI = 0.227, 0.442), a Mixed DP (β = 0.241; 95% CI = 0.160, 0.323), and a Healthy + Sweets DP (β = 0.160; 95% CI = 0.061, 0.260), and inversely associated with an Ultra-processed DP (β = -0.116; 95% CI = -0.207, -0.026). Breakfast consumption was associated with overall DPs, suggesting the importance of eating this meal by schoolchildren. We emphasise the relevance of offering a healthy breakfast at public schools for students who do not take this meal at home, contributing to health promotion.

Attendance in physical education classes, sedentary behavior, and different forms of physical activity among schoolchildren: a cross-sectional study

Background

Attendance in physical education classes (PE) helps young people to achieve the physical activity recommendations and to reduce their exposure to sedentary behavior. However, the association between PE attendance and the daily frequency of specific forms of physical activity is less known. The current study analyzed the association between weekly attendance in PE and daily frequencies of different forms of physical activity (active play, non-active play, structured physical activity), and overall daily frequencies of physical activity (PA) and sedentary behaviors (SB) among schoolchildren.

Methods

Cross-sectional study with schoolchildren from second to fifth grade of 11 public schools (n = 2,477; 9.1 ± 1.38-y-old; 53.2% girls; 17.5 ± 3.5 kg/m²) in Feira de Santana (Northeast Brazil). PA, SB, and attendance in PE were self-reported using a previously validated on-line questionnaire based on the previous day's recall (Web-CAAFE). Multiple Binomial Negative regression modeling was carried out to analyze the association (Prevalence Rate: PR) between weekly attendance in PE (0/week, 1/week, ≥ 2/week) and frequencies of active play, non-active play, and structured physical activity, with adjustments by age, school shift, and BMI z-scores. Regression models analyzing overall PA also included adjustments by household chores.

Results

Attendance in PE ≥ 2/week was associated with higher frequencies of active play (girls: PR = 1.40, 95%CI = 1.11–1.78; boys: PR = 1.49, 95%CI = 1.15–1.94) and structured physical activity (girls: PR = 2.11, 95%CI = 1.31–3.40; boys: PR = 4.33, 95%CI = 1.63–11.52). Higher attendance in PE (≥ 2/week) was associated with high overall PA (girls: PR = 1.31, 95%CI = 1.06–1.62; boys: PR = 1.42, 95%CI = 1.14–1.77) and low SB (girls: PR = 0.80, 95%CI = 0.71–0.90; boys: PR = 0.81, 95%CI = 0.68–0.97). Attendance in PE 1/week was also associated with a lower frequency of daily SB among girls (PR = 0.73, 95%IC = 0.64–0.84)

Conclusion

Higher weekly attendance in PE was associated with higher frequencies of active play, structured physical activity, higher overall PA, and lower SB among both girls and boys.

Time trend estimation of food consumption in repeated studies with different versions of food questionnaire among Brazilian schoolchildren aged 7 to 11 years

Abstract Longitudinal study, whose objective was to evaluate of the time trend in food consumption across the 2002-2015 period in schoolchildren aged 7 to 11 years, covered five food surveys in Florianopolis, southern Brazil. Methodological differences across the surveys (typical vs. previous day food consumption, pen-and-paper versus computer screen presentation) and some known risk factors, were adjusted for statistically. Offset by maximum food/beverage consumption per day allowed comparability of a varying number of food components in a food group over survey years. Significant reduction in some healthy (fruits and animal proteins) and unhealthy diet markers (sodas, sugary drinks, sweets) was observed over the 2013-2015 period compared with the 2002 and 2007 data. Computer screen presentation of the food questionnaire systematically reduced the reporting frequency compared to the pen-and-paper presentation. Converting frequency reports into rates and using contrast analysis allowed time trend estimation based on food questionnaires with different presentation modes, varying number of items within food group over survey years, and variations in probabilistic sampling procedures.

Development of a Food-Based Diet Quality Scale for Brazilian Schoolchildren Using Item Response Theory

Item response theory (IRT) is a psychometric method that provides probabilistic model-based measurements. Its use is relatively recent in the assessment of food consumption, especially through dietary assessment tools. This study aims (1) to develop a food-based diet quality scale for Brazilian schoolchildren using IRT, and (2) to apply the scale to a representative sample of schoolchildren from a Southern Brazilian city. The scale was developed with daily consumption frequency of foods from 835 students who completed the Food Intake and Physical Activity of Schoolchildren questionnaire. Questionnaire foods were grouped into 10 items according to their nutritional similarities and were evaluated by full-information factor analysis that indicated a dominant factor explaining 28% of the variance. Psychometric item analysis was performed using Samejima’s model. The scale covered all levels of diet quality, from “very poor” (scores < 95) to “very good” (scores ≥ 130). Children who had higher diet quality scores consumed beans, meat, fish, eggs, fruits, vegetables, dairy products, and water more frequently, while reducing the consumption of ultraprocessed sugary foods, ultraprocessed savoury snacks and sausages, and sugary drinks. Of 6323 children, an average of less than 10% consumed the highest diet quality scores (good or very good diet quality) and about 60% of children consumed low diet quality scores. The scale can be applied to other schoolchildren with the same measure precision.

A Web-Based Time-Use Application to Assess Diet and Movement Behavior in Asian Schoolchildren: Development and Usability Study of My E-Diary for Activities and Lifestyle (MEDAL)

Background

Web-based time-use diaries for schoolchildren are limited, and existing studies focus mostly on capturing physical activities and sedentary behaviors but less comprehensively on dietary behaviors.

Objective

This study aims to describe the development of My E-Diary for Activities and Lifestyle (MEDAL)—a self-administered, web-based time-use application to assess diet and movement behavior—and to evaluate its usability in schoolchildren in Singapore.

Methods

MEDAL was developed through formative research and an iterative user-centric design approach involving small groups of schoolchildren (ranging from n=5 to n=15, aged 7-13 years). To test the usability, children aged 10-11 years were recruited from 2 primary schools in Singapore to complete MEDAL for 2 weekdays and 2 weekend days and complete a 10-item usability questionnaire.

Results

The development process revealed that younger children (aged <9 years) were less able to complete MEDAL independently. Of the 204 participants (118/204, 57.8% boys, and 31/201, 15.4% overweight) in the usability study, 57.8% (118/204) completed 3 to 4 days of recording, whereas the rest recorded for 2 days or less. The median time taken to complete MEDAL was 14.2 minutes per day. The majority of participants agreed that instructions were clear (193/203, 95.1%), that MEDAL was easy to use (173/203, 85.2%), that they liked the application (172/202, 85.1%), and that they preferred recording their activities on the web than on paper (167/202, 82.7%). Among all the factors evaluated, recording for 4 days was the least satisfactory component reported. Compared with boys, girls reported better recall ability and agreed that the time spent on completing 1-day entry was appropriate.

Conclusions

MEDAL appears to be a feasible application to capture diet and movement behaviors in children aged 10-12 years, particularly in the Asian context. Some gender differences in usability performance were observed, but the majority of the participants had a positive experience using MEDAL. The validation of the data collected through the application is in progress.

Obesity and decrease of daily physical activity among children and adolescents: a follow-up study

ABSTRACT We analyzed the effect of obesity on daily physical activity (DPA), light-intensity physical activity (LPA), moderate-intensity physical activity (MPA) and vigorous- intensity physical activity (VPA) in children and adolescents. Overall, 462 students from a public school (53.6% boys; aged 7-12 years) were involved in this one-year longitudinal study. Physical activities and sedentary behaviors (SB) were reported in the questionnaire Food Intake and Physical Activity of Students (Web-CAAFE). Obesity was evaluated through Body Mass Index (BMI z score ≥ 2). Obesity was observed in 16.5% of participants, but it did not influence LPA, MPA or DPA. However, VPA were 20% less frequent among obese students (β2=0.80; CI 95%: 0.66-0.98). Obese girls showed less frequency of VPA than non-obese boys (Mean Difference = -0.97; CI 95%: -1.36 to -0.57). Non-obese girls showed less VPA than non-obese boys (Mean Difference = -1.18; CI 95%: -1.40 to -0.95) and obese ones (Mean Difference = -0.57; CI 95%: -0.90 to -0.24). Obese boys showed fewer VPA, if compared to non-obese ones (Mean Difference = -0.61; CI 95%: -0.96 to -0.26). The analysis of the obesity-sex-age interaction showed a greater reduction in VPA among obese girls aged 10 years or more when compared to obese girls aged 7-9 years, and among boys obese and non-obese regardless of age. Amounts of VPA and SB increased simultaneously among non-obese boys and non-obese children aged 7-9 years. Obesity reduced VPA in the sample during the follow up of one year, independently of age and SB.

Meal and snack patterns of 7-13-year-old schoolchildren in southern Brazil

OBJECTIVE

The aim of the current study was to identify and describe the meal and snack patterns (breakfast, mid-morning snack, lunch, mid-afternoon snack, dinner and evening snack) of public schoolchildren.

DESIGN

Cross-sectional study. Information on the previous day's food intake was obtained through the Web-CAAFE (Food Intake and Physical Activity of Schoolchildren), an interactive questionnaire, which divides daily food consumption into three meals (breakfast, lunch and dinner) and three snacks (mid-morning, mid-afternoon and evening). Each meal contains thirty-one food items and the schoolchildren clicked on the food items consumed in each meal. Factor analysis was used to identify meal and snack patterns. The descriptions of the dietary patterns (DP) were based on food items with factor loads ≥ 0·30 that were considered representative of each DP.

SETTING

Schoolchildren, Florianopolis, Brazil.

PARTICIPANTS

Children (n 1074) aged 7-13 years.

RESULTS

Lunch was the most consumed meal (96·0 %), followed by dinner (86·4 %), breakfast (85·3 %) and mid-afternoon snack (81·7 %). Four DP were identified for breakfast, mid-morning snack, lunch, dinner and evening snack, and three for mid-afternoon snack. Breakfast, lunch and dinner patterns included traditional Brazilian foods. DP consisting of fast foods and sugary beverages were also observed, mainly for the evening snack.

CONCLUSIONS

The results of the current study provide important information regarding the meal and snack patterns of schoolchildren to guide the development of nutrition interventions in public health.

The relationship between lifestyle components and dietary patterns

We conducted a narrative review on the interaction between dietary patterns with demographic and lifestyle variables in relation to health status assessment. The food pattern has the advantage of taking into account the correlations that may exist between foods or groups of foods, but also between nutrients. It is an alternative and complementary approach in analysing the relationship between nutrition and the risk of chronic diseases. For the determination of dietary patterns one can use indices/scores that evaluate the conformity of the diet with the nutrition guidelines or the established patterns (a priori approach). The methods more commonly used are based on exploratory data (a posteriori): cluster analysis and factor analysis. Dietary patterns may vary according to sex, socio-economic status, ethnicity, culture and other factors, but more, they may vary depending on different associations between these factors. The dietary pattern exerts its effects on health in a synergistic way or even in conjunction with other lifestyle factors, and we can therefore refer to a 'pattern of lifestyle'.

Multilevel analysis of factors that influence overweight in children: research in schools enrolled in northern Brazil School Health Program

BACKGROUND

The study evaluates children in schools that participate in the School Health Program in the Northern region of Brazil with the objective of assessing whether their schools interfered in the development of overweight/obesity and how individual and school environment variables behave according to contextual analysis.

METHODS

The analyses were carried out with 1036 children from 25 municipal public schools in Northern Brazil that participated in the School Health Program. We evaluated both individual characteristics and scholar environment through univariate and multivariate logistic regressions to identify which of these factors were related to overweight/obesity as well as the effect of varying such associations.

RESULTS

The considered individuals had an median age of 8 years, being 54.9% female and 27.8% presenting overweight/obesity. In multivariate logistic regression, the overweight/obesity variance in schools was 0.386 (individual variables) and 0.102 (individual and school variables), explaining 23.7% of the variation, reduction of ICC and MOR. The Akaike Information Criterion between the models was reduced and the likelihood ratio indicated better adequacy of the latter model. The investigated children had a greater chance of developing overweight/obesity when they performed 2+ sedentary activities/day, depending on school location as well as whether or not candies were sold in the school surroundings. On the other hand, a lower chance of developing overweight/obesity was identified in children that ate 5+ meals/day and practiced dance at school.

CONCLUSION

We observed that the variables inherent to both individuals and schools favored the development of overweight/obesity in children. It is relevant that scholar curriculums incorporate healthy eating interventions and encourage body practices associated with policies that restrain the sale of ultra-processed food in schools as well as the development of intersectoral actions between education and health to control childhood obesity.

Efeito do dia e do número de dias de aplicação na reprodutibilidade de um questionário de avaliação do consumo alimentar de escolares

RESUMO: Introdução: O questionário de Consumo Alimentar e Atividade Física de Escolares (Web-CAAFE) foi desenvolvido para o monitoramento da dieta e atividade física de escolares brasileiros. Este estudo buscou avaliar o efeito do dia da semana e do número de aplicações na reprodutibilidade do Web-CAAFE. Metodologia: Escolares do 2º ao 5º ano (n = 197) de Florianópolis preencheram o Web-CAAFE por duas vezes no mesmo dia, dos quais 113 o fizeram em três dias não consecutivos. Avaliou-se a reprodutibilidade por meio da correlação intraclasse (CCI) e da regressão logística, para avaliação dos fatores associados à pior reprodutibilidade. Resultados: Observaram-se piores resultados de reprodutibilidade para o preenchimento do consumo nos finais de semana em relação àqueles que responderam em dias da semana (odds ratio - OR = 2,93; p = 0,045) e melhores resultados em meninas em relação aos meninos (OR = 0,29; p < 0,001). O preenchimento do consumo realizado nos segundo e terceiro dias apresentou melhor reprodutibilidade que o realizado no primeiro. Esses resultados são relevantes para o planejamento de futuros estudos que utilizem instrumentos de consumo alimentar em crianças, em especial sobre avaliação de sua validade e reprodutibilidade. Conclusões: Os resultados sugerem que pelo menos dois dias de aplicação do Web-CAAFE fornecem resultados aceitáveis de reprodutibilidade, e que o preenchimento referente ao fim de semana pode reduzi-la.

Trends in food consumption of schoolchildren from 2nd to 5th grade: a panel data analysis

ABSTRACT Objective To identify trends in food consumption among schoolchildren (2nd-5th grades) from public schools in the city of Florianópolis, Brazil, in a period of three years. Methods Three cross-sectional surveys were carried out in 2013 (n=1,942), 2014 (n=1,989) and 2015 (n=2,418). Dietary intake data were obtained using the Web-Based Food Intake and Physical Activity of Schoolchildren questionnaire. Food items were aggregated to eight food groups. Kruskal-Wallis heterogeneity and trend tests were used to analyze the differences and trends among the mean intake frequency of food groups. Results There were trends to decrease the mean intake frequency of sweets in the total sample (2013: 0.72±0.91; 2014: 0.68±0.87; 2015: 0.67±0.89, p=0.03) which was determined by children between 7-9 years old (2013: 0.69±0.88; 2014: 0.64±0.85; 2015: 0.62±0.87, p=0.02), and boys (2013: 0.75±0.90; 2014: 0.70±0.86; 2015: 0.68±0.88, p=0.03). Younger children also tended to increase the mean intake frequency of fruits and vegetables (2013: 1.03±1.35; 2014: 1.16±1.45; 2015: 1.17±1.41, p=0.03) and those aged ten-12 years decreased their intake of dairy products (2013: 1.32±1.25; 2014: 1.23±1.18; 2015: 1.20±1.20, p=0.05). Conclusion The results suggest positive trends for younger children, with an increased consumption of fruits and vegetables in both sexes and decreased consumption of sweets for boys. Older children reduced their consumption of dairy products over the three-year period of this study.

Empirically derived dietary patterns through latent profile analysis among Brazilian children and adolescents from Southern Brazil, 2013-2015

The aims of this study were to identify dietary patterns (DPs) of children and adolescents participating in three cross-sectional surveys (2013-2015) and to test their associations with sociodemographic variables, physical activity (PAS), screen-based sedentary activity (SA), and weight status. One-day data were obtained from 5,364 schoolchildren (7-12 years) from public schools of Florianopolis (South of Brazil), using the validated questionnaire Web-CAAFE (Food Intake and Physical Activity of Schoolchildren). DPs were derived from the frequency of daily consumption of 32 foods/beverages by latent profile analysis. Multinomial logistic regression analysis was used to estimate the association of the DPs with sociodemographic variables, physical activity, screen activity and weight status. 'Traditional', 'Monotonous', and 'Mixed' DPs were identified. The percentages of children and adolescents within these profiles were 41.3, 36.3, and 22.4%, respectively. Children and adolescents in the highest tertiles of both PAS and daily frequency of SA had a higher probability to present a 'Mixed' DP compared to peers with less PAS and SA. Children and adolescents who reported having a school meal were significantly more likely to present the 'Traditional'DP, while boys who did not report having a school meal had a higher probability to present the 'Monotonous' DP. The DPs were not associated with the year of survey, age, family income, or weight status.

A Web-Based Interactive Tool to Reduce Childhood Obesity Risk in Urban Minority Youth: Usability Testing Study

Background

Childhood obesity is a serious public health issue among minority youth in the United States. Technology-enhanced approaches can be effective for promoting healthy behavior change.

Objective

The purpose of this study was to test the usability of prototypes of a Web-based interactive tool promoting healthy dietary behaviors to reduce childhood obesity risk in urban minority youth. The Web-based tool comprised a manga-style comic with interactive features (eg, sound effects, clickable pop-ups), tailored messaging, and goal setting, and was optimized for use on tablet devices.

Methods

Latino and black/African American children ages 9 to 13 years were recruited to participate in two rounds of usability testing. A modified think-aloud method was utilized. Self-reported surveys and field notes were collected. Audio recordings and field notes from usability testing sessions were systematically reviewed by extracting and coding user feedback as either positive comments or usability or negative issues. The quantitative data from self-reported questionnaires were analyzed using descriptive statistics.

Results

Twelve children (four female; eight black/African American) with a mean age of 10.92 (SD 1.16) years participated. Testing highlighted overall positive experiences with the Web-based interactive tool, especially related to storyline, sound effects, and color schemes. Specific usability issues were classified into six themes: appearance, content, special effects, storyline, terminology, and navigation. Changes to the Web-based tool after round 1 included adding a navigation guide, making clickable icons more visible, improving graphic designs, and fixing programming errors. In round 2 of testing (after modifications to the Web-based tool were incorporated), many of the usability issues that were identified in round 1 did not emerge.

Conclusions

Results of testing will inform further development and finalization of the tool, which will be tested using a two-group pilot randomized study, with the goal of reducing childhood obesity risk in minority, low-income youth.

Consistency evaluation of values of weight, height, and body mass index in Food Intake and Physical Activity of School Children: the quality control of data entry in the computerized system

INTRODUCTION

The quality control of data entry in computerized questionnaires is an important step in the validation of new instruments. The study assessed the consistency of recorded weight and height on the Food Intake and Physical Activity of School Children (Web-CAAFE) between repeated measures and against directly measured data.

METHODS

Students from the 2nd to the 5th grade (n = 390) had their weight and height directly measured and then filled out the Web-CAAFE. A subsample (n = 92) filled out the Web-CAAFE twice, three hours apart. The analysis included hierarchical linear regression, mixed linear regression model, to evaluate the bias, and intraclass correlation coefficient (ICC), to assess consistency. Univariate linear regression assessed the effect of gender, reading/writing performance, and computer/internet use and possession on residuals of fixed and random effects.

RESULTS

The Web-CAAFE showed high values of ICC between repeated measures (body weight = 0.996, height = 0.937, body mass index - BMI = 0.972), and regarding the checked measures (body weight = 0.962, height = 0.882, BMI = 0.828). The difference between means of body weight, height, and BMI directly measured and recorded was 208 g, -2 mm, and 0.238 kg/m², respectively, indicating slight BMI underestimation due to underestimation of weight and overestimation of height. This trend was related to body weight and age.

CONCLUSION

Height and weight data entered in the Web-CAAFE by children were highly correlated with direct measurements and with the repeated entry. The bias found was similar to validation studies of self-reported weight and height in comparison to direct measurements.

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

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

[Validity and reproducibility of an Internet-based questionnaire (Web-CAAFE) to evaluate the food consumption of students aged 7 to 15 years]

The study evaluated the validity and reproducibility of the food consumption section of the questionnaire Food Intake and Physical Activity of School Children (Web-CAAFE), an Internet-based software for the qualitative measurement of food consumption by recalling the previous day. A total of 390 students in grades 2 to 5 (7 to 15 years) of a semi-integral public school participated in the study. The validity was tested by comparing the report in the Web-CAAFE and the direct observation of food consumed in the school in the previous day. The reproducibility was evaluated in a sub-sample of 92 schoolchildren, by comparing repeated reports in the Web-CAAFE on the same day. Probabilities of accuracy in the Web-CAAFE report in relation to the observation (matches, omissions and intrusions and respective 95% confidence intervals) among seven food groups were estimated through multinomial logistic regression. The average for the match rate was 81.4% (variation: 62% sweets and 98% beans); for the omission rate was 16.2% (variation between 2.1% dairy products and 28.5% sweets); for the intrusion rate was 7.1% (variation between 1.3% beans and 13.8% cereals). Sweets, cereals and processed foods, snack foods and fried foods simultaneously exhibited higher rates of omission and intrusion. Students 10 years of age or older had lower probabilities of intruding food items. There were no significant variations in the accuracy of the report between repeated measures. The Web-CAAFE was a valid and reliable instrument for the evaluation of food consumption, when applied to students in grades 2 to 5 of public schools.

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.

AVALIAÇÃO DA ATIVIDADE FÍSICA DE ESCOLARES COM UM QUESTIONÁRIO VIA INTERNET

RESUMO Introdução: A atividade física é um comportamento que se estabelece na infância, tende a se manter na vida adulta e influencia a regulação do balanço energético, do peso e da adiposidade corporal, prevenindo a obesidade. Por isso, criar e validar métodos de avaliação e monitoramento da atividade física de crianças e adolescentes no nível populacional é necessário para formular políticas públicas. Objetivo: Avaliar validade e reprodutibilidade de comportamentos sedentários e atividades físicas autorrelatadas no questionário Consumo Alimentar e Atividade Física de Escolares (Web-CAAFE), um instrumento computacional baseado na internet. Métodos: Escolares do 2º ao 5º ano (n = 390) foram observados durante o horário do recreio e preencheram o questionário no dia seguinte. Uma subamostra (n = 94) preencheu o Web-CAAFE duas vezes com três horas de intervalo. O custo energético, como equivalentes metabólicos (MET), foi calculado para cada atividade física e somado ao nível do indivíduo. O MET individual de atividades físicas e o total de comportamentos sedentários autorrelatados foram os principais desfechos analisados separadamente, utilizando regressão de Poisson e regressão de Poisson hierárquica (aluno no primeiro nível e a repetição dos métodos no segundo nível). Os resultados foram apresentados como razões de incidências (RI). Os resíduos foram analisados graficamente por sexo e idade. Resultados: O Web-CAAFE superestimou o total de comportamentos sedentários (RI = 2,90, IC 95%: 2,05-4,10), principalmente entre as garotas mais jovens (7-10 anos), enquanto as mais velhas (11-15 anos) tenderam à subestimação. A superestimação nos MET de atividades físicas foi menor e não estatisticamente significante. Não houve diferença estatisticamente significante no total de comportamentos sedentários ou MET de atividades físicas entre o primeiro e o segundo autorrelato. Conclusão: O Web-CAAFE mostrou boa confiabilidade e maior precisão quando aplicado à avaliação de MET de atividades físicas dos estudantes mais velhos.

The use of multiple imputation method for the validation of 24-h food recalls by part-time observation of dietary intake in school

External validation of food recall over 24 h in schoolchildren is often restricted to eating events in schools and is based on direct observation as the reference method. The aim of this study was to estimate the dietary intake out of school, and consequently the bias in such research design based on only part-time validated food recall, using multiple imputation (MI) conditioned on the information on child age, sex, BMI, family income, parental education and the school attended. The previous-day, web-based questionnaire WebCAAFE, structured as six meals/snacks and thirty-two foods/beverage, was answered by a sample of 7-11-year-old Brazilian schoolchildren (n 602) from five public schools. Food/beverage intake recalled by children was compared with the records provided by trained observers during school meals. Sensitivity analysis was performed with artificial data emulating those recalled by children on WebCAAFE in order to evaluate the impact of both differential and non-differential bias. Estimated bias was within ±30 % interval for 84·4 % of the thirty-two foods/beverages evaluated in WebCAAFE, and half of the latter reached statistical significance (P<0·05). Rarely (<3 %) consumed dietary items were often under-reported (fish/seafood, vegetable soup, cheese bread, French fries), whereas some of those most frequently reported (meat, bread/biscuits, fruits) showed large overestimation. Compared with the analysis restricted to fully validated data, MI reduced differential bias in sensitivity analysis but the bias still remained large in most cases. MI provided a suitable statistical framework for part-time validation design of dietary intake over six daily eating events.

Sedentary behavior during school-time: Sociodemographic, weight status, physical education class, and school performance correlates in Brazilian schoolchildren

OBJECTIVES

To investigate whether sedentary behavior during school-time is associated with gender, age, mother's education, having physical education classes, weight status, and academic performance.

DESIGN

Cross-sectional study.

METHODS

A sample of 571 children (7-12 years old) from five elementary schools in Florianopolis, South Brazil had their height and weight measured, and wore accelerometers during class time. Teachers completed a form to evaluate children's reading and writing skills. Parents provided sociodemographic and educational information. Data was analyzed using multilevel linear regression analyses.

RESULTS

Children spent an average of 132min in sedentary behavior during school-time (64% of total school-time). Girls (137.5min), obese children (138.1min), older children (144.2min), and those who did not have physical education classes (140.2min) spent more time engaged in sedentary activities than their peers. Academic performance and mother's education were not associated with sedentary behaviors.

CONCLUSIONS

Children spent most of their school-time in sedentary activities, with girls, older students, and obese students being even more sedentary than their peers. Physical education classes were a protective factor against excessive sedentary behavior in school. Interventions for reducing sedentary behavior during school-time could employ additional strategies to benefit the at risk groups. In addition, encouraging student's participation in physical education classes could minimize the time spent in sedentary behavior during school hours.

Validity of WebCAAFE questionnaire for assessment of schoolchildren's dietary compliance with Brazilian Food Guidelines

OBJECTIVE

To estimate reporting bias of WebCAAFE, a web-based questionnaire for the assessment of food intake (recall of frequency of intake of thirty-two food items the day before) and physical activity in schoolchildren.

DESIGN

Cross-sectional study. Self-reported food intake on WebCAAFE was compared with direct observation of school meals in five public schools. Additional data included school grade, sex, BMI, socio-economic status and access to Internet at home. Poisson regression was used to calculate the reporting bias (WebCAAFE v. direct observation) and the sample size necessary to detect a statistically significant difference between WebCAAFE reports and at least 75 % compliance with the recommendations for a healthy diet.

SETTING

Intentional sample of five elementary public schools in Florianopolis, Brazil.

SUBJECTS

Schoolchildren (n 629) from 2nd to 5th grades.

RESULTS

Moderate bias magnitude was found for most food groups of interest. Frequency of consumption was not related to the bias. Sample sizes necessary to detect the compliance with dietary recommendations varied between four and seventy-four individuals for the different groups investigated.

CONCLUSIONS

After adjusting for moderate bias, WebCAAFE may be used as a food questionnaire for evaluation of schoolchildren's food compliance on a group level, even with a relatively small sample size.

Recruitment via the Internet and social networking sites: the 1989-1995 cohort of the Australian Longitudinal Study on Women's Health

Background

Faced with the challenge of recruiting young adults for health studies, researchers have increasingly turned to the Internet and social networking sites, such as Facebook, as part of their recruitment strategy. As yet, few large-scale studies are available that report on the characteristics and representativeness of the sample obtained from such recruitment methods.

Objective

The intent of the study was to describe the sociodemographic and health characteristics of a national sample of young Australian women recruited mainly through the Internet and social networking sites and to discuss the representativeness of their sociodemographic, health, and lifestyle characteristics relative to the population.

Methods

A cohort of 17,069 women (born between 1989 and 1995) was recruited in 2012-13 for the Australian Longitudinal Study on Women’s Health. Sociodemographic characteristics (percentages, means, and 95% confidence intervals) from the online survey data were compared with women aged 18-23 years from the 2011 Australian Census. Sample data were compared by age and education level with data from the 2011-13 Australian Health Survey (AHS).

Results

Compared to the Australian Census data, study participants were broadly representative in terms of geographical distribution across Australia, marital status (95.62%, 16,321/17,069) were never married), and age distribution. A higher percentage had attained university (22.52%, 3844/17,069) and trade/certificate/diploma qualifications (25.94%, 4428/17,069) compared with this age group of women in the national population (9.4% and 21.7% respectively). Among study participants, 22.05% (3721/16,877) were not in paid employment with 35.18% (5931/16,857) studying 16 or more hours a week. A higher percentage of study participants rated their health in the online survey as fair or poor (rather than good, very good, or excellent) compared with those participating in face-to-face interviews in the AHS (18.77%, 3203/17,069 vs 10.1%). A higher percentage of study participants were current smokers (21.78%, 3718/17,069 vs 16.4%) and physically active (59.30%, 10,089/17,014 were classified as sufficiently active vs 48.3%) but alcohol consumption was lower (59.58%, 9865/16,558 reported drinking alcohol at least once per month vs 65.9% in the AHS). Using self-reported height and weight to determine body mass index (BMI, kg/m²), 34.80% (5901/16,956) of the cohort were classified as overweight or obese (BMI of 25 or more), compared with 33.6% respectively using measured height and weight in the AHS.

Conclusions

Findings indicated that using the Internet and social networking sites for an online survey represent a feasible recruitment strategy for a national cohort of young women and result in a broadly representative sample of the Australian population.

Web-based assessments of physical activity in youth: considerations for design and scale calibration

This paper describes the design and methods involved in calibrating a Web-based self-report instrument to estimate physical activity behavior. The limitations of self-report measures are well known, but calibration methods enable the reported information to be equated to estimates obtained from objective data. This paper summarizes design considerations for effective development and calibration of physical activity self-report measures. Each of the design considerations is put into context and followed by a practical application based on our ongoing calibration research with a promising online self-report tool called the Youth Activity Profile (YAP).

We first describe the overall concept of calibration and how this influences the selection of appropriate self-report tools for this population. We point out the advantages and disadvantages of different monitoring devices since the choice of the criterion measure and the strategies used to minimize error in the measure can dramatically improve the quality of the data. We summarize strategies to ensure quality control in data collection and discuss analytical considerations involved in group- vs individual-level inference. For cross-validation procedures, we describe the advantages of equivalence testing procedures that directly test and quantify agreement. Lastly, we introduce the unique challenges encountered when transitioning from paper to a Web-based tool. The Web offers considerable potential for broad adoption but an iterative calibration approach focused on continued refinement is needed to ensure that estimates are generalizable across individuals, regions, seasons and countries.

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.