Prevalence of overweight and associated factors in southern Brazilian adolescents

Prevalence of overweight and obesity among Brazilian adolescents over time: a systematic review and meta-analysis

OBJECTIVE

To estimate the burden of excess weight in Brazilian adolescents.

DESIGN

Systematic review with meta-analysis.

SETTING

We searched the literature in four databases (MEDLINE/PubMed, EMBASE, SciELO and LILACS). Studies were included if they had cross-sectional or cohort design and enrolled Brazilian adolescents. Studies based on self-reported measures were excluded. Random effect models were used to calculate prevalence estimates and their 95 % CI.

PARTICIPANTS

Brazilian adolescents (10 to 19 years old).

RESULTS

One hundred and fifty-one studies were included. Trend analyses showed a significant increase in the prevalence of excess weight in the last decades: 8·2 % (95 % CI 7·7, 8·7) until year 2000, 18·9 (95 % CI 14·7, 23·2) from 2000 to 2009, and 25·1 % (95 % CI 23·4, 26·8) in 2010 and after. A similar temporal pattern was observed in the prevalence of overweight and obesity separately. In sensitivity analyses, lower prevalence of excess weight was found in older adolescents and those defined using International Obesity Task Force cut-off points. The Southeast and South regions had the highest prevalence of excess weight, overweight and obesity. No significant difference in prevalence by sex was found, except for studies before the year 2000.

CONCLUSIONS

The prevalence of overweight and obesity in Brazilian adolescents is high and continues to rise. Public policies on an individual level and targeting modifications in the obesogenic environment are necessary.

Prevalence of excessive screen time and TV viewing among Brazilian adolescents: a systematic review and meta-analysis

PURPOSE

To evaluate the prevalence of excessive screen-based behaviors among Brazilian adolescents through a systematic review with meta-analysis.

DATA SOURCE

Systematic review and meta-analysis were recorded in the International Prospective Register of Ongoing Systematic Reviews (PROSPERO-CRD 2017 CRD42017074432). This review included observational studies (cohort or cross-sectional) that evaluated the prevalence of excessive screen time (i.e. combinations involving different screen-based behaviors) or TV viewing (≥2h/day or >2h/day in front of screen) through indirect or direct methods in adolescents aged between 10 and 19 years. The research strategy included the following databases: MEDLINE, LILACS, SciELO and ADOLEC. The search strategy included terms for "screen time", "Brazil", and "prevalence". Random effect models were used to estimate the prevalence of excessive screen time in different categories.

DATA SUMMARY

Twenty-eight out of 775 studies identified in the search met the inclusion criteria. The prevalence of excessive screen time and TV viewing was 70.9% (95% CI: 65.5-76.1) and 58.8% (95% CI: 49.4-68.0), respectively. There was no difference between sexes in both analyses. The majority of studies included showed a low risk of bias.

CONCLUSIONS

The prevalence of excessive screen time and TV viewing was high among Brazilian adolescents. Intervention are needed to reduce the excessive screen time among adolescents.

A systematic review of factors affecting energy intake of adolescent girls

BACKGROUND

Adolescence is considered a critical period marked by an increase in energy intake to meet the body's physiological needs especially during puberty. This study reviews existing literature and critically analyses factors associated with eating habits and energy intake of adolescent girls.

METHODS

A comprehensive search was conducted to identify at least 200 peer reviewed articles which dealt with the factors affecting energy intake (EI) and eating habits of adolescent girls. Studies were identified using a reference period between 1994 and 2016, based primarily on the PubMed/ CINL/ Science Direct/Google Scholar databases using keywords adolescent/ teenagers, factors/determinants and energy intake.

RESULTS

No studies investigated all factors affecting energy intake among adolescents. Some studies found mixed association among the determinants of EI in adolescent girls. However, a number of reviews confirm that many factors namely physical activity level, socio-economic status, diet, individual and social factors do contribute to either a higher or a lower EI of adolescents.

CONCLUSION

There is a dire need to consider factors associated with EI when designing nutritional intervention programs to prevent health problems in adulthood. The goal is not to change behavior of all but to increase the percentage of people adopting healthier lifestyle.

Sedentary behavior in Brazilian children and adolescents: a systematic review

OBJECTIVE

To describe the methodological characteristics of the studies selected and assess variables associated with sedentary behavior in Brazilian children and adolescents.

METHODS

For this systematic review, we searched four electronic databases: PubMed, Web of Knowledge, LILACS, SciELO. Also, electronic searches were applied in Google Scholar. A supplementary search was conducted in the references lists of the included articles and in non-indexed journals. We included observational studies with children and adolescents aged from three to 19 years developed in Brazil, presenting analyses of associations based on regression methods and published until September 30, 2014.

RESULTS

Of the 255 potential references retrieved by the searches, 49 met the inclusion criteria and composed the descriptive synthesis. In this set, we identified a great number of cross-sectional studies (n = 43; 88.0%) and high methodological variability on the types of sedentary behavior assessed, measurement tools and cut-off points used. The variables most often associated with sedentary behavior were "high levels of body weight" (in 15 out of 27 studies; 55.0%) and "lower level of physical activity" (in eight out of 16 studies; 50.0%).

CONCLUSIONS

The findings of this review raise the following demands to the Brazilian agenda of sedentary behavior research geared to children and adolescents: development of longitudinal studies, validation of measuring tools, establishment of risk cut-offs, measurement of sedentary behavior beyond screen time and use of objective measures in addition to questionnaires. In the articles available, the associations between sedentary behavior with "high levels of body weight" and "low levels of physical activity" were observed in different regions of Brazil.

Trends in prevalence of overweight and obesity: are Portuguese adolescents still increasing weight?

OBJECTIVE

To report the prevalence and trends of the BMI of Portuguese adolescents in 2002, 2006 and 2010.

METHODS

4138 boys and 4472 girls self-reported weight, height, physical activity, perception of health and life satisfaction.

RESULTS

For adolescents aged 11-13 years, the prevalence of overweight/obesity decreased from 23.5 % in 2002 to 20.7 % in 2010, using IOTF cutoff points, and decreased from 32.4 to 28.4 % between 2002 and 2010 using WHO cutoff points. For adolescents aged 15-17 years, the prevalence increased from 13.9 to 16.8 % between 2002 and 2010 using IOTF cutoff, and increased from 14.8 % in 2002 to 18.2 % in 2010 when using WHO cutoff points. Although the prevalence decreased among younger adolescents and increased among older ones, the differences were not significant. Physical activity in the last 7 days (p < 0.05), better life satisfaction (p < 0.05) and perception of health (p < 0.001) predicted lower body mass index z score.

CONCLUSIONS

Overall, there have been no significant changes in overweight and obesity prevalence in Portuguese adolescents from 2002 to 2010. However, the prevalence remains high and therefore it is important to continue surveillance.

Childhood and adolescent overweight and obesity in Latin America: a systematic review

The number of children and adolescents who are overweight or obese worldwide is alarming. We did a systematic review to estimate the prevalence of overweight and obesity in children aged 0-19 years in Latin America. We searched specialised databases and seven books for relevant studies that were done in Spanish-speaking and Portuguese-speaking Latin American and Caribbean countries and published in peer-reviewed journals between January 2008, and April 2013. Indicators used were BMI (kg/m(2)) in all age groups and weight-for-height in children younger than 5 years. We identified 692 publications and included 42. Estimated prevalence of overweight in children younger than 5 years in Latin America was 7·1% with the weight-for-height WHO 2006 classification method. National combined prevalences of overweight and obesity with the WHO 2007 classification method ranged from 18·9% to 36·9% in school-age children (5-11 years) and from 16·6% to 35·8% in adolescents (12-19 years). We estimated that 3·8 million children younger than 5 years, 22·2-25·9 million school-age children, and 16·5-21·1 million adolescents were overweight or obese. Overall, between 42·5 and 51·8 million children aged 0-19 years were affected-ie, about 20-25% of the population. Although undernutrition and obesity coexist in the region, policies in most countries favour prevention of undernutrition, and only a few countries have implemented national policies to prevent obesity. In view of the number of children who are overweight or obese, the associated detrimental effects on health, and the cost to health-care systems, implementation of programmes to monitor and prevent unhealthy weight gain in children and adolescents are urgently needed throughout Latin America.

Epidemiology of physical inactivity, sedentary behaviors, and unhealthy eating habits among brazilian adolescents

This systematic review analyzed the prevalence of physical inactivity, sedentary behaviors and unhealthy eating habits among Brazilian adolescents. Searches were conducted in five databases (Lilacs, SciELO, Medline, Web of Science, and Google Scholar) and in the references cited in the articles retrieved. The literature search yielded 5,872 potentially relevant titles and a total of 69 studies met all the inclusion criteria. The risk behavior most often evaluated was physical inactivity (48/69; 69.6%), and its prevalence rate ranged from 2.3% to 93.5%. Twenty-eight studies estimated the prevalence of physical inactivity at over 50%. Most studies observed the prevalence of greater physical inactivity among girls. The prevalence of sedentary behaviors (lengthy screen time or TV use) was also frequently over 50%. Several variables were used to identify unhealthy eating habits, and some criteria/studies have indicated unhealthy eating habit estimates at close to 100% among adolescents. In conclusion, the estimates of these risk behaviors among Brazilians adolescents were very close to or even greater than those found in developed countries in several studies analyzed in this review.

The health benefits of dietary fiber: beyond the usual suspects of type 2 diabetes mellitus, cardiovascular disease and colon cancer

Dietary fiber (DF) is deemed to be a key component in healthy eating. DF is not a static collection of undigestible plant materials that pass untouched or unencumbered through the gastrointestinal (GI) tract; instead, DFs are a vast array of complex saccharide-based molecules that can bind potential nutrients and nutrient precursors to prevent their absorption. Some DFs are fermentable, and the GI tract catabolism leads to the generation of various bioactive materials, such as short-chain fatty acids (SCFAs), that can markedly augment the GI tract biomass and change the composition of the GI tract flora. The health benefits of DFs include the prevention and mitigation of type 2 diabetes mellitus, cardiovascular disease and colon cancer. By modulating food ingestion, digestion, absorption and metabolism, DFs reduce the risk of hyperlipidemia, hypercholesterolemia and hyperglycemia. Emerging research has begun to investigate the role of DFs in immunomodulation. If substantiated, DFs could facilitate many biologic processes, including infection prevention and the improvement of mood and memory. This review describes the accepted physiologic functions of DFs and explores their new potential immune-based actions.

Prevalência de excesso de peso e seus fatores associados em adolescentes da rede de ensino público de Piracicaba, São Paulo

OBJETIVO: Estimar a prevalência de excesso de peso e os fatores associados à sua ocorrência em adolescentes da rede de ensino público da cidade de Piracicaba, São Paulo. MÉTODOS: Estudo transversal de 269 adolescentes de ambos os sexos, com idades entre dez a 14 anos. Foram aplicados questionários para obtenção do consumo alimentar, maturação sexual, nível de atividade física e características demográficas. Para a análise estatística utilizou-se a regressão logística univariada e múltipla. RESULTADOS: A prevalência de excesso de peso foi de 35,7% entre os meninos e 26,2%, entre as meninas. Os fatores associados foram observados somente entre as meninas, mostrando-se protetor ao excesso de peso o 2º tercil de consumo de carboidrato (OR ajustada 0,28) e a fase de aceleração/pico do crescimento (OR ajustada 0,37). CONCLUSÕES: A prevalência de excesso de peso nos adolescentes é preocupante. A fase de aceleração/pico do crescimento e o alto consumo de carboidrato foram relacionados como fatores protetores para o excesso de peso entre as meninas. Sugere-se ainda que este último fator seja analisado com cautela, dado que tal associação não foi observada em outros estudos.

Socio-demographic and lifestyle factors associated with overweight in a representative sample of 11-15 year olds in France: results from the WHO-Collaborative Health Behaviour in School-aged Children (HBSC) cross-sectional study

Background

The prevalence of overweight in children and adolescents is high and overweight is associated with poor health outcomes over short- and long-term. Lifestyle factors can interact to influence overweight. Comprehensive studies linking overweight concomitantly with several demographic and potentially-modifiable lifestyle factors and health-risk behaviours are limited in adolescents - an age-group characterized by changes in lifestyle behaviours and high prevalence of overweight. Thus, the objective of the current study was to examine the association of overweight with several socio-demographic and lifestyle variables simultaneously in a representative sample of adolescents.

Methods

A nationally representative sample of 11-15 year-olds (n = 7154) in France participated as part of the WHO-Collaborative Health Behaviour in School-aged Children (HBSC) study. Students reported data on their age, height, weight, socio-demographic variables, lifestyle factors including nutrition practices, physical activity at two levels of intensity (moderate and vigorous), sedentary behaviours, as well as smoking and alcohol consumption patterns using standardized HBSC protocols. Overweight (including obesity) was defined using the IOTF reference. The multivariate association of overweight with several socio-demographic and lifestyle factors was examined with logistic regression models.

Results

The adjusted odds ratios for the association with overweight were: 1.80 (95% CI: 1.37-2.36) for low family affluence; 0.73 (0.60-0.88) for eating breakfast daily; 0.69 (0.56-0.84) for moderate to vigorous physical activity (MVPA); and 0.71 (0.59-0.86) for vigorous physical activity (VPA). Significant interactions between age and gender as well as television (TV) viewing and gender were noted: for boys, overweight was not associated with age or TV viewing; in contrast, for girls overweight correlated negatively with age and positively with TV viewing. Fruit and vegetable intake, computer and video-games use, smoking and alcohol consumption were not associated with overweight.

Conclusions

In multivariate model, family affluence, breakfast consumption and moderate to vigorous as well as vigorous physical activity were negatively associated with overweight. These findings extend previous research to a setting where multiple risk and protective factors were simultaneously examined and highlight the importance of multi-faceted approaches promoting physical activity and healthy food choices such as breakfast consumption for overweight prevention in adolescents.

Health-promoting effects of a dietary fiber concentrate from the soybean byproduct okara in rats

Okara (a byproduct of the soy milk industry) is rich in proteins (24.5-37.5 g/100 g of dry matter (dm)), lipids (9.3-22.3 g/100 g of dm), and dietary fiber (DF) (14.5-55.4 g/100 g of dm). It also contains isoflavones (0.14 g/100 g of dm). In the present study we fed female healthy Wistar rats either a standard rat diet or a supplemented 10% DF-rich okara (DFRO) diet for 4 weeks, and then we assessed several health parameters in the serum and the cecum compartments. In comparison to the control group, rats fed DFRO showed a significant decrease in weight gain (5.00 +/- 1.22 g vs 2.00 +/- 1.46 g, P < 0.03, during week 4) and in total cholesterol (65 +/- 8 mg/dL vs 51 +/- 5 mg/dL, P < 0.05) and a significantly increased antioxidant status (36.71 +/- 15.31 micromol of Trolox equivalents (TEs)/g vs 69.75 +/- 16.11 micromol of TEs/g, P < 0.0003) and butyrogenic effect (39.37%, P < 0.003) in the cecum. In addition, a significant enhancement in the apparent absorption (41.89 +/- 1.64% vs 47.02 +/- 2.51%, P < 0.004) and in the true retention (41.62 +/- 1.60% vs 46.68 +/- 2.55%, P < 0.005) of calcium was appreciated. In summary, these findings show for the first time that a concentrate DF from a soybean byproduct protects the gut environment in terms of antioxidant status and prebiotic effect. These results may highlight the development of an innovative soybean byproduct rich in DF which could be useful as a functional ingredient with health-promoting attributes.