Valorization of kiwi waste through composting.

Kiwi waste from the calibration process is a major environmental problem of kiwi production due to landfill deposition. This work aims to contribute to the agronomic use of recycled kiwi waste through composting. With this objective, a composting experiment was carried out with kiwi fruit waste mixed with 5%, 10% and 20% (fresh weight) of wheat straw from bundles used to protect kiwifruit trunks from frost, as abulking agent to increase aeration, in the piles 5S, 10S and 20S, respectively. The highest temperatures for piles 5S and 10S were above 60°C, whereas the temperature did not reach 40°C in the pile with the highest straw content (20S) because the aeration increased heat loss in addition to increased C/N ratio of this pile. Also, the amount of organic matter mineralized decreased with increasing amount of straw because of the high C/N ratio of the straw. The highest total N (29.7 g kg-1) and the lowest C/N ratio (13) of the compost with 5% of straw is important from the agricultural point of view to promote N availability. In contrast, the high electrical conductivity (4.6 dS m-1) of this compost increases the risk of salt accumulation in the soil. Our results show that the compost with 10% straw, with high degree of maturation, absence of poor hygiene indicators as coliforms and pathogens as Salmonella sp., high organic matter content and rich in nutrients, together with the adequate compost pH and low electrical conductivity improves compost quality.

Prevalence of overweight and obesity in 3-to-10-year-old children: assessment of different cut-off criteria WHO-IOTF.

This study compares the prevalence of overweight and obesity between WHO/IOTF criteria. A total of 17,277 Portuguese children aged 3-10 years old were analysed. The prevalences of overweight-obesity were higher at WHO classification (19.8%-20.7%) than at IOTF classification (8.2%-16.1%), (p<0.001). Agreement between the criteria were substantial for overweight (Kappa= 0.67, p<0.001) and moderate for obesity (Kappa= 0.47, p<0.001). The prevalences ratio for inequality between criteria were greater for boys than for girls and lesser for children aged 6-7 than children aged 8-10 years old. The disparities between the two criteria and the higher overweight obesity prevalences highlight the needs to develop more studies.

The association of irregular sleep habits with the risk of being overweight/obese in a sample of Portuguese children aged 6-9 years.

OBJECTIVES: The consequences of irregular sleep duration at younger ages remains uncertain, especially when we consider shorter and longer than recommended sleep durations. Therefore, the present study aimed to analyze the association between healthy sleep duration and risk of obesity in Portuguese children. METHODS: The sample for this cross-sectional study comprised 8273 children (4183 females) aged 6-9 years. Height and weight were measured and body mass index (BMI) was calculated. Sleep habits and sedentary behaviors (i.e., TV viewing) were assessed by questionnaire. Logistic regressions were used. RESULTS: After adjustments for confounders, males who have irregular sleep duration were 1.28 times more likely to be classified as overweight or obese than their counterparts who had normal sleep duration on weekdays. No associations between sleep duration and overweight/obesity risk were found for girls, neither on weekdays nor on the weekend. For both boys and girls, the final model showed a significant inverse association between overweight/obesity risk and the educational level of fathers (males: 95% CI 0.51 to 0.79, P < .001; females: 95% CI 0.57 to 0.87, P < .01). CONCLUSION: Findings revealed that shorter and longer than recommended sleep duration was positively associated with risk of obesity in boys on weekdays. Furthermore, pediatric obesity risk could be highly influenced by the education level of fathers of both males and females. Future research should extend a similar design, using objective measures of sleep duration to confirm some of the afore-mentioned results.

Eating away from home: a risk factor for overweight in children.

The present study examined the association between childhood overweight, children's meals and eating out in three types of restaurants (traditional Portuguese food restaurant, fast-food restaurant and snack bar). A representative sample of Portuguese children (5706 boys; 5950 girls aged 6-11 years) was used for this analysis and an ethnographic study with 233 interviews of the owners of snack bars in Coimbra (Portugal). Weight and height were measured (body mass index was consequently calculated). A familial and nutritional questionnaire was filled out by parents. Logistic regressions were used. Findings revealed that eating out at snack bars may be a risk for children's health because those who eat out at these food establishments have a 21% higher risk of being overweight than those peers who do not eat out at snack bars. In conclusion, findings revealed a statistically significant association between overweight and eating out at snack bars in boys.

Waist-to-height ratio and its association with TV viewing in a sample of Portuguese children aged 7-9 years.

INTRODUCTION: During the past decades, increased TV viewing and reduced physical activity (PA) levels may have contributed to the increased prevalence of pediatric obesity. This study aimed to analyze the association between TV viewing and central adiposity risk in Portuguese children. METHODS: The sample comprised 3987 children (1997 girls and 1990 boys) aged 7-9 years. Height, weight, and waist circumference (WC) were measured. Waist-to-height ratio (WHtR) was calculated as the ratio of waist/height with a cut-off of 0.5 used to define risk of abdominal obesity. WHtR does not depend on sex- or age-specific reference criteria. TV viewing and PA were assessed by questionnaire. Logistic regressions were used, with adjustments for age, PA, and parental education. RESULTS: This study revealed a positive significant association between central adiposity risk and sedentary behaviors in Portuguese boys. In addition, the final model showed an important inverse association between PA and the risk of abdominal obesity in both boys and girls (males: ß = -0.01 95% CI, 0.99 to 1.00; females: ß = -0.01; 95% CI, 0.99-1.00). CONCLUSION: Findings revealed that associations between TV viewing and obesity risk could be highly influenced by socioeconomic factors. Future research should extend a similar design to children in other geographic contexts, and incorporate other behavioral variables in the statistical models, to confirm or not some of the aforementioned findings.

Co-composting of invasive Acacia longifolia with pine bark for horticultural use.

The feasibility of commercial-scale co-composting of waste biomass from the control of invasive Acacia species with pine bark waste from the lumber industry, in a blend ratio of 60:40 (v:v), was investigated and compared with previous research on the composting of Acacia without additional feedstock, to determine the potential process and end-product quality benefits of co-composting with bark. Pile temperatures rose rapidly to >70 °C and were maintained at >60 °C for several months. Acacia and bark biomass contained a large fraction of mineralizable organic matter (OM) equivalent to approximately 600 g kg(-1) of initial OM. Bark was more recalcitrant to biodegradation compared with Acacia, which degraded at twice the rate of bark. Therefore, incorporating the bark increased the final amount of compost produced compared with composting Acacia residues without bark. The relatively high C/N ratio of the composting matrix (C/N=56) and NH3 volatilization explained the limited increases in NH4+-N content, whereas concentrations of conservative nutrient elements (e.g. P, K, Ca, Mg, Fe) increased in proportion to OM mineralization, enriching the compost as a nutrient source for horticultural use. Nitrogen concentrations also increased to a small extent, but were much more dynamic and losses, probably associated with N volatilization mechanisms, were difficult to actively control. The physicochemical characteristics of the stabilized end-product, such as pH, electrical conductivity and OM content, were improved with the addition of bark to Acacia biomass, and the final compost characteristics were suitable for use for soil improvement and also as horticultural substrate components.

Active commuting and its associations with blood pressure and adiposity markers in children.

OBJECTIVE: The positive impacts of active travel on health markers still require further research, especially in youth populations with higher risk of obesity. The present study aimed to analyze the associations between blood pressure and adiposity risk (BPAR) and active travel to school in children. METHODS: The sample comprised 665 Portuguese children (345 boys) aged 7-9 years. Data on height, weight, and skinfold thickness were collected by a trained fieldworker as well as data on BPAR between March 2009 and January 2010 (data were analyzed in 2012-2013). Information on mode and duration of travel to school (i.e. exposure) was gathered by questionnaire. Outcome variables were statistically normalized and expressed as Z scores. A BPAR score was computed as the mean of the Z scores. Multiple linear regression, with adjustments for confounders, was used. RESULTS: Active commuting was inversely associated with BPAR after adjustment for several potential confounders. After adjusting for BMI, the strength of the relationship between BPAR and active commuting was significantly improved (p≤0.01). CONCLUSIONS: Findings showed an independent association between the clustered BPAR and active commuting in children aged 7-9 years.

Parental perceptions of neighborhood environments, BMI, and active behaviors in girls aged 7-9 years.

OBJECTIVES: Habitual physical activity (PA) may be influenced by a broad range of neighborhood, school, community, and family factors. Young people, particularly girls, tend to show lower habitual PA than boys and should be a target for prevention strategies aimed at healthy lifestyles. The purpose of this study was twofold: (1) to determine which perceived attributes about neighborhoods are related to active behaviors; (2) to analyze which perceived attributes about neighborhoods are related to body mass index (BMI) of children. METHODS: The sample was comprised of 1,886 girls aged 7-9 years. Height and weight were measured, and BMI was calculated subsequently. Participants were classified as normal weight or overweight/obese (Cole et al. [2000]: BMJ 320: 1240-1243). Environmental variables and physical activities were assessed by questionnaire filled out by their parents-the Environmental Module of the International Physical Activity Prevalence Study (IPS, 2002) was used. Multiple linear regressions, with adjustments for confounding variables, were used. RESULTS: Data revealed that neighborhoods with recreational facilities and infrastructure for walking and cycling were predictors of active behaviors; neighborhood safety was an additional related factor of habitual PA. On the other hand, neighbors with better access to destinations and with interesting things to look at while walking were significantly associated with lower BMI in Portuguese children. CONCLUSION: The study found some significant relationships between parental perceptions of the environment and BMI and habitual PA of Portuguese girls, especially related to security for walking and unpleasant neighborhoods, and access to destinations.

Composting for management and resource recovery of invasive Acacia species.

The feasibility of commercial-scale composting of waste biomass from the control of invasive Acacia species was investigated. Pile temperatures exceeded 65ºC for several months, indicating that the composting process was effective at pathogen inactivation and seed destruction. Mineralisation of Acacia biomass was described by a two-component, first-order exponential model; the pool sizes for labile and recalcitrant organic matter (OM) were similar and in the approximate ranges: 360-410 g kg(-1) and 350-390 g kg(-1) of initial OM, respectively. Concentrations of conservative nutrients increased proportionally to OM mineralisation, enriching the compost as an agricultural nutrient source. Nitrogen concentrations also increased, but were more dynamic as nitrogen losses were difficult to control, although we suggest that they may be potentially minimised by restricting the turning frequency. The physicochemical characteristics of the stabilised end-product, and the high OM content and low electrical conductivity (<1.2 dS m(-1)), in particular, were suitable for soil improvement or as substrate components.

The associations of SES, obesity, sport activity, and perceived neighborhood environments: is there a model of environmental injustice penalizing Portuguese children?

OBJECTIVES: This study analyses the associations between children's obesity, sports activity (SA), and perceived environmental characteristics with the children's SES. METHODS: A sample of 1,885 Portuguese children, aged 3-10 years, living in Coimbra, Portugal, was observed. Weight and height were measured and obesity was defined by age-and sex-specific, BMI cut-off points. Questionnaires included variables on SA levels, SES and parental neighborhood perceptions were done. A CATPCA was performed and two neighborhood dimensions were achieved. The independent associations of SES with obesity, SA and perceived neighborhood dimensions was analyzed using ordered logistic regressions. RESULTS: Children of low [odds ratio (OR) = 1.76; confidence interval (CI) = 1.25-1.99] and medium SES (OR = 1.57; CI = 1.34-2.33) were more likely to be obese than their high-SES peers, less likely to participate in SA (low SES OR = 0.177; CI = 0.12-0.26; medium SES OR = 0.357; CI = 0.24-0.53), and their parents were less likely to have positive perceptions of their built environment (low SES OR = 0.516; CI = 0.38-0.70; medium SES OR = 0.565; CI = 0.37-0.86). CONCLUSIONS: Obesity increases and SA decreases among children with the lowest SES and these living in neighborhoods with higher perceived risk. This finding suggests a model of environmental injustice, whereby differential access to the neighborhood's resources overlaps with familial socioeconomic disadvantage.

Type-specific screen time associations with cardiovascular risk markers in children.

BACKGROUND: There is evidence that TV time may have stronger associations with cardiovascular risk markers than other types of screen time, but most studies focus on TV, or total screen time. PURPOSE: To examine associations between types of screen time and cardiovascular risk markers in school-age children. METHODS: Cross-sectional study of 2515 school children in Portugal (aged 2-12 years, data collected in 2009 and 2010). Three types of screen time (TV, electronic games, and PC time) were collected through a questionnaire, and data on three cardiovascular risk markers (resting heart rate; diastolic blood pressure [DBP]; and systolic blood pressure [SBP]) were collected by a trained fieldworker. Complex-samples generalized linear models were run for each combination of screen time predictor and cardiovascular risk outcome, and a clustered cardiovascular risk score, adjusting for potential confounders (including physical activity). Analyses were conducted in 2011 and 2012. RESULTS: TV viewing, but not PC or electronic games time, was associated positively with clustered cardiovascular risk score, DBP, and SBP after adjustment for all covariates. Watching TV for >2 hours/day (compared to <1 hour/day) was associated with higher DBP (coefficient, logged and back-transformed 0.02, 95% CI=0.00, 0.04, linear trend p=0.003); SBP (logged and back-transformed 0.02, 95% CI= -0.01, 0.05, p=0.009), and clustered cardiovascular risk score (0.13, 95% CI=0.02, 0.24, p<0.001). CONCLUSIONS: TV viewing, but no other type of screen time, was associated positively with cardiovascular risk markers independently of physical activity. Studies using a single marker of screen time or sedentary behavior may conceal screen time type-specific associations.

Associations between indicators of screen time and adiposity indices in Portuguese children.

OBJECTIVES: To examine associations between three types of screen time (TV, electronic games (EG), and personal computer (PC)) and two proxies of adiposity (body mass index (BMI) and sum of skinfolds) in children. DESIGN: The sample comprised 17,509 children aged 2-13 years who participated in the 2009/10 Portuguese Prevalence Study of Obesity in Childhood. METHODS: Complex samples generalised linear models, using school as a cluster variable were ran separately for each combination of ST predictor and adiposity-related outcome, adjusting for covariates including age, sex, physical activity, diet, and parental factors. Missing values in predictors and covariates were imputed. RESULTS: Watching TV for >2h/day compared to <1h/day was associated with higher age- and sex-specific BMI standard deviation score (coefficient: 0.06, 95% CI: 0.01 to 0.12, linear trend p=0.008) and sum of skinfolds (logged and back transformed 0.04, 0.02 to 0.07, p=<0.001). We also found weak evidence for an inverse association between PC and BMI. CONCLUSIONS: Associations between ST and adiposity differ by both type of ST and type of adiposity marker. Only TV viewing was consistently associated with adiposity. Studies using a single adiposity marker looking at total screen time or total sedentary behaviour time may miss or confound type-specific associations.

Association between parental perceptions of residential neighbourhood environments and childhood obesity in Porto, Portugal.

BACKGROUND: Portugal has one of the highest rates of childhood obesity in Europe. Few studies have explored the relationship between parents' perceptions of their residential neighbourhood (safety concerns and amenities of the built environment) and their children's weight status. This study aims to examine the associations between parents' perceptions of their residential neighbourhood and overweight/obesity among their children. METHODS: Anthropometric measures of height and weight were taken for 2690 children in preschools and elementary schools in Porto. Body mass index (kg/m(2)) was calculated, and the International Obesity Taskforce (IOTF) cut-offs were used. Parents completed the 'Environmental Module' standard questionnaire of the International Physical Activity Prevalence Study. Chi-square tests and the logistic regression model adjusted for age, gender, maternal education and school cluster were used to examine the associations between parents' perceptions of their residential neighbourhood and overweight/obesity among their children. RESULTS: In this sample, 31.8% of the children were overweight (including obese). Significant associations were found between child obesity and the following residential environmental characteristics: the odds of children being obese were lower if their parents believed that it was safe (low/no crime rate) to walk/cycle at night (OR = 0.65, 95% CI = 0.54-0.79) and during the day (OR = 0.70, 95% CI = 0.55-0.86) and that it was easy and pleasant (pedestrian safety) to walk in their neighbourhoods (OR = 0.73, 95% CI = 0.58-0.90) and when local sidewalks were well maintained and unobstructed (OR = 1.18, 95% CI = 1.01-1.40). CONCLUSION: Parental perceptions of neighbourhood safety and the quality of local sidewalks are significantly associated with obesity values.

Perceptions of neighborhood environments and childhood obesity: evidence of harmful gender inequities among Portuguese children.

This study investigates the links between parents' perceptions of their social and built residential environment and obesity among Portuguese school boys and girls. A total of 1885 children, 952 girls and 933 boys, aged 3.0-10.0 years, were observed. The children's weight and height were measured, and their parents filled out the "Environmental Module" questionnaire of the International Physical Activity Prevalence Study. Age and sex-speci`fic BMI cut-off points were used to define being overweight/obese. Environmental characteristics were combined into 2 composite neighborhood indices that were used as predictors in logistic regression models. Girls living in neighborhoods perceived as having poorly built environmental conditions had increased odds of being obese (OR=1.47; p<0.005), and girls living in neighborhoods perceived as being unsafe and dangerous had also increased odds of being obese (OR=1.339; p<0.005). These relationships were not evident for boys. Improvements in the neighborhood environment could be a strategy for tackling the growing epidemic of childhood obesity and can simultaneously contribute to reduce health inequities across population subgroups.

[Prevalence of nutritional inadequacy among Portuguese children]. / Prevalência de inadequação nutricional em crianças portuguesas.

Obesity is one of the most serious health problems in children, and it's frequently related to low activity levels and inadequate nutrition. To evaluate the prevalence of nutritional inadequacy a total of 4845 children (2445 girls and 2400 boys) aged 7-9 years old, were observed. Height and weight were measured according to international standards, and body mass index (BMI) was calculated. Overweight and obesity, using age- and sex-specific BMI cut-off points as defined by the International Obesity Taskforce, were used. Children's dietary intake was measured using a 24-h dietary recall by trained researchers. To evaluate nutritional inadequacy, Food and Nutrition Board Dietary Reference Intakes and World Health Organization (WHO) recommended intake goals were used. The prevalence of overweight/obesity in this sample was 30.8% and the proportion of children with an intake below the Estimated Average Intake/Adequate Intake was very low (= 10%) for the following nutrients: vitamins A, B1, B2, B6, B12, and PP; and for magnesium, zinc, iodine, phosphorous, selenium, and iron. High prevalences of inadequacy were found for folate (60.5% in girls and 54.6% in boys), vitamin E (63.9% in girls and 59.5% in boys), calcium (45% in girls and 40.7% in boys), molybdenum (89.7% in girls and 87.4% in boys, and fibre (87.8% in girls and 86.7% in boys). Regarding the macronutrients, 65.9% and 78.8% of the individuals were above WHO recommended intake values for protein and total fats, respectively; 22% didn't ingest lower than WHO carbohydrates intake recommendation. We've also found that 81.4% and 97.3% of the individuals were above WHO recommendations for saturated fatty acids and total sugars, respectively. Regarding cholesterol intake, 53% of the individuals ingested more than the recommended by WHO. In conclusion, the prevalence of inadequate intakes of calcium, vitamin E, folate, molybdenum and fibre was unacceptably high, while and the contribution of total fat, saturated fat and sugars were far above the recommended by WHO. This could be associated to major chronic diseases, such as coronary heart diseases, in later life.

Long sleep duration and childhood overweight/obesity and body fat.

To assess the association between short sleep duration and overweight/obesity and body fat (BF) and to identify correlates of short sleep duration in a sample of Portuguese children. A cross-sectional study of children 7-9 years (n = 4511) was performed between October 2002 and June 2003. Weight, height, and skinfolds were measured, and parents filled out a questionnaire about family characteristics as well as sleep duration. The prevalence of overweight/obesity and BF (%) both decreased by long sleep duration. After adjusted for confounders, the odds ratio (OR) for overweight/obesity and sleep duration were as follows: reference >11 h/d; 10-11 h/d, OR: 1.3; confidence interval (CI):1.26, 1.33; 9-10 h/d, OR: 1.16; CI: 1.13, 1.19; and <9 h, OR: 3.22; CI: 3.11, 3.32. Children whose parents had a low educational level slept less time during each night than children whose parents had a higher educational level; children who spent more time watching television slept less time than those who watched less television, and those children engaged in physical activity slept more time each night than sedentary children. Our results showed an inverse relationship between long sleep duration and overweight/obesity prevalence as well as with body fat, and these findings are important because sleep duration is a potentially modifiable risk factor that could be important to consider in the prevention and treatment of childhood obesity.

Prevalence and risk factors for overweight and obesity in Portuguese children.

AIM: To identify risk factors for overweight and obesity in Portuguese children. METHODS: A cross-sectional study of children 7 to 9.5 y old was performed between October 2002 and June 2003. A total of 2,274 girls and 2,237 boys were observed. Weight and height were measured, and parents filled out a questionnaire about family characteristics. Overweight and obesity, using age- and sex-specific body mass index (BMI) cut-off points as defined by the International Obesity Taskforce, were used. RESULTS: After adjustment for age and sex, the odds ratio for childhood obesity increased by television viewing (reference 0-2 h; 2-3 h: 1.51; 3-4 h: 1.72; 4 h: 1.63), paternal obesity (reference <18.5 kg/m(2); 25.0-29.9: 3.06; 30.0: 7.09), maternal obesity (reference <18.5 kg/m(2); 25.0-29.9: 9.06; 30.0: 18.13) and birthweight (reference <2,500 g; 2,500-3,000 g: 1.55; 3,000-3,500 g: 1.87; 3,500-4,000 g: 2.13; 4,000 g: 2.74), and decreased by sleeping duration (reference 8 h/d; 9-10 h/d: 0.44; 11 h/d: 0.39), paternal education (reference primary school; secondary: 0.91; university: 0.42), maternal education (reference primary school; secondary: 1.13; university: 0.56), being a single child (reference yes; no: 0.56) and family size (reference one child; two children: 0.59; three children: 0.44; more than four children: 0.37). CONCLUSION: Our data support the perspective that education about energy intake and energy expenditure should be used much earlier in those families with high-risk children, namely those with high parental BMI or high birthweight. Protective factors were parental education and family size.