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

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.

Trends in the prevalence of obesity, overweight, and thinness among schoolchildren aged 7-14 years from southern Brazil (2002-2019)

OBJECTIVE

To analyze the obesity, overweight, and thinness trends among Brazilian schoolchildren by sex, age group, and type of school according to World Health Organization (WHO) and International Obesity Task Force (IOTF) criteria.

METHODS

We conducted four surveys between 2002 and 2018/19 involving schoolchildren aged 7-14 years from a state capital in southern Brazil. Weight status was classified using both WHO and IOTF criteria.

RESULTS

In the total sample, obesity prevalence based on the IOTF and the WHO criteria were 72% and 44% higher in 2018/19 compared with 2002, respectively. Over the whole period, the obesity prevalence increased among children (WHO: 10.1% vs. 14.1%; IOTF: 5.0% vs. 8.3%), and those from public schools (WHO: 10.5% vs. 16.4%; IOTF: 5.6% vs. 10.1%). There was no significant reduction in thinness prevalence over the analyzed period.

CONCLUSION

Obesity prevalence remains on an upward trend in a state capital in southern Brazil, especially among children from public schools. A higher prevalence of overweight and obesity was observed using the WHO criteria compared with IOTF criteria.

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.

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.