Browsing by Author "Onywera, Vincent"

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    Are Children Like Werewolves? Full Moon and Its Association with Sleep and Activity Behaviors in an International Sample of Children
    (Frontiers Media, 2016) Chaput, J-P.; Weippert, Madyson; LeBlanc, Allana G.; Hjorth, Mads F.; Michaelsen, Kim F.; Katzmarzyk, Peter T.; Tremblay, Mark S.; Barreira, Tiago V.; Broyles, Stephanie T.; Fogelholm, Mikael; Hu, Gang; Kuriyan, Rebecca; Kurpad, Anura; Lambert, Estelle V.; Maher, Carol; Maia, Jose; Matsudo, Victor; Olds, Timothy; Onywera, Vincent; Sarmiento, Olga L.; Standage, Martyn; Tudor-Locke, Catrine; Zhao, Pei; Sjödin, Anders M.
    In order to verify if the full moon is associated with sleep and activity behaviors, we used a 12-country study providing 33,710 24-h accelerometer recordings of sleep and activity. The present observational, cross-sectional study included 5812 children ages 9–11 years from study sites that represented all inhabited continents and wide ranges of human development (Australia, Brazil, Canada, China, Colombia, Finland, India, Kenya, Portugal, South Africa, United Kingdom, and United States). Three moon phases were used in this analysis: full moon (±4 days; reference), half moon (±5–9 days), and new moon (±10–14 days) from nearest full moon. Nocturnal sleep duration, moderate-tovigorous physical activity (MVPA), light-intensity physical activity (LPA), and total sedentary time (SED) were monitored over seven consecutive days using a waist-worn accelerometer worn 24 h a day. Only sleep duration was found to significantly differ between moon phases (~5 min/night shorter during full moon compared to new moon). Differences in MVPA, LPA, and SED between moon phases were negligible and non-significant (<2 min/day difference). There was no difference in the associations between study sites. In conclusion, sleep duration was 1% shorter at full moon compared to new moon, while activity behaviors were not significantly associated with the lunar cycle in this global sample of children. Whether this seemingly minimal difference is clinically meaningful is questionable
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    Association between dietary behaviours and weight status of school children: results from the International Study of Childhood Obesity, Lifestyle and the Environment (ISCOLE) -Kenya
    (Taylor & Francis, 2020) Wachira, Lucy-Joy; Muthuri, Stella; Ochola, Sophie; Onywera, Vincent; Tremblay, Mark
    Background: Sub-Saharan African countries are undergoing rapid urbanization resulting in vast changes in dietary habits. Dietary practices involving excess energy intake have been associated with overweight/obesity. We assessed the dietary behaviour of children and their relationships with weight status. Methods: Data was collected in Kenya, as part of the International Study of Childhood Obesity, Lifestyle and the Environment (ISCOLE). The study recruited 563 children aged 9–11 years from 29 schools in Nairobi. A seven-day food frequency questionnaire was used to assess dietary intake. Dietary behaviours such as consumption of breakfast, school lunch, meals prepared/eaten away from home, emotional eating and snacking while watching television were also assessed. Body mass index (BMI-for-age and sex) was used as the indicator of weight status. Results: Of the sample, 53.5% were girls; 20.8% were classified as overweight/ obese; 72.9% ate meals out of home regularly; 55.2% ate lunch provided by the school; and only 76% had breakfast on all weekdays. Eating more when happy, eating fried foods while watching television, and consumption of vegetables were positively associated with BMI. Majority of overweight children were female (56.6%) and the type of school attended predicted BMI, F(6, 536) = 18.371, p < 0.0001, R2 = 0.171. BMI was negatively associated with consumption of cakes/pastries (χ2 = 14.7, V = 0.165, p = 0.023), potato crisps (χ2 = 21.6, V = 0.197, p = 0.003), and fast foods (χ2 = 13.5, p = 0.036). ANOVA results revealed no significant differences in the consumption of foods with BMI except for vegetables (p = 0.003). Conclusions: Children have healthy diets rich in fruits and vegetables and low in energy-dense foods. Also, less healthy diets were observed in children with lower BMI. There is need for interventions targeting the overweight/obese children, particularly those of higher SES.
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    Breastfeeding and childhood obesity: A 12-country study
    (Wiley, 2020) Ma, Jian; Qiao, Yijuan; Zhao, Pei; Li, Wei; Katzmarzyk, Peter T.; Chaput, Jean-Philippe; Fogelholm, Mikael; Kuriyan, Rebecca; Lambert, Estelle V.; Maher, Carol; Maia, Jose; Matsudo, Victor; Olds, Timothy; Onywera, Vincent; Sarmiento, Olga L.; Standage, Martyn; Tremblay, Mark S.; Tudor-Locke, Catrine; Hu, Gang
    This study aimed to examine the association between breastfeeding and childhood obesity. A multinational cross-sectional study of 4,740 children aged 9–11 years was conducted from 12 countries. Infant breastfeeding was recalled by parents or legal guardians. Height, weight, waist circumference, and body fat were obtained using standardized methods. The overall prevalence of obesity, central obesity, and high body fat were 12.3%, 9.9%, and 8.1%, respectively. After adjustment for maternal age at delivery, body mass index (BMI), highest maternal education, history of gestational diabetes, gestational age, and child's age, sex, birth weight, unhealthy diet pattern scores, moderate-to-vigorous physical activity, sleeping, and sedentary time, exclusive breastfeeding was associated with lower odds of obesity (odds ratio [OR] 0.76, 95% confidence interval, CI [0.57, 1.00]) and high body fat (OR 0.60, 95% CI [0.43, 0.84]) compared with exclusive formula feeding. The multivariable-adjusted ORs based on different breastfeeding durations (none, 1–6, 6–12, and > 12 months) were 1.00, 0.74, 0.70, and 0.60 for obesity (Ptrend = .020) and 1.00, 0.64, 047, and 0.64 for high body fat (Ptrend = .012), respectively. These associations were no longer significant after adjustment for maternal BMI. Breastfeeding may be a protective factor for obesity and high body fat in 9- to 11-year-old children from 12 countries.
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    Differences Between Health- and Skill-Related Physical Fitness Profiles of Kenyan Children from Urban and Rural Areas: The Kenya-LINX Project
    (Int. J. Environ. Res. Public Health, 2025-04) Kinuthia, Stanley Kagunda; Stratton, Gareth; Wachira, Lucy Joy; Okoth, Victor; Owino, George Evans; Ochola, Sophie; Amie, Bethan Richards; Kiplamai, Festus; Onywera, Vincent; Swindell, Nils
    Physical fitness is a key indicator of children’s health, yet amidst rising inactivity and obesity, data on Kenyan children are scarce. This study assessed health- and skill-related fitness differences between rural and urban Kenyan children while examining demographic influences. Cardiorespiratory fitness (CRF), BMI, strength, flexibility, speed, agility, and coordination were assessed in 1131 children aged 11.07 ± 0.9 years (52.7% girls) recruited using stratified cluster random sampling. Significant rural–urban disparities were observed. In urban areas, 16.6% were overweight and 2.8% obese, compared to 4% and 0.6% in rural areas (p < 0.001). Conversely, 44.5% of the rural cohort were underweight versus 13.7% urban cohort (p < 0.001). Multivariable regression revealed that rural children demonstrated superior CRF (β = −4.68 laps, p < 0.001) and lower back flexibility (β = −2.77 cm, p < 0.001), while urban children excelled in speed and coordination (β = 3.68 bounces, p < 0.001) and grip strength (β = 2.16 kg, p < 0.001). Boys outperformed girls in explosive leg power (β = −6.75 cm, p < 0.001) and CRF (β = −6.92 laps, p < 0.001). These findings highlight fitness inequities among Kenyan children, emphasising the need for equitable, targeted, and inclusive physical activity opportunities.
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    Epidemiological Transition in Physical Activity and Sedentary Time in Children
    (Human Kinetics Publishers Inc., 2019) Barreira, Tiago V.; Broyles, Stephanie T.; Tudor-Locke, Catrine; Chaput, Jean-Philippe; Fogelholm, Mikael; Hu, Gang; Kuriyan, Rebecca; Lambert, Estelle V.; Maher, Carol A.; Maia, José A.; Olds, Timothy; Onywera, Vincent; Sarmiento, Olga L.; Standage, Martyn; Tremblay, Mark S.; Katzmarzyk, Peter T.
    To determine if children’s moderate to vigorous physical activity (MVPA) and sedentary time varied across levels of household income in countries at different levels of Human Development Index (HDI), consistent with the theory of epidemiological transition. Methods: Data from 6548 children (55% girls) aged 9–11 years from 12 countries at different HDI levels are used in this analysis to assess MVPA and sedentary time (measured using ActiGraph accelerometers) across levels of household income. Least-square means are estimated separately for boys and girls at the estimated 10th, 50th, and 90th percentiles of HDI for the sample. Results: For boys, time in MVPA is negatively associated with income at the 10th and 50th percentiles of HDI (both P < .002). For girls, time in MVPA is negatively associated with income at the 10th and 50th percentiles of HDI (all P < .01) and positively related with income at the 90th percentile (P = .04). Sedentary time is positively associated with income at the 10th percentile of HDI for boys (P = .03), but not for girls. Conclusions: Results support the possibility of an epidemiological transition in physical activity, with lower levels of MVPA observed at opposite levels of income depending on the HDI percentile. This phenomenon was not observed for sedentary time.
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    Joint Association of Birth Weight and Physical Activity/ Sedentary Behavior with Obesity in Children Ages 9-11 Years from 12 Countries
    (Wiley, 2017) Qiao, Yijuan; Zhang, Tao; Liu, Hongyan; Katzmarzyk, Peter T.; Chaput, J-P.; Fogelholm, Mikael; Johnson, William D.; Kuriyan, Rebecca; Kurpad, Anura; Lambert, Estelle V.; Maher, Carol; Maia, Jose A.R.; Matsudo, Victor; Olds, Timothy; Onywera, Vincent; Sarmiento, Olga L.; Standage, Martyn; Tremblay, Mark S.; Tudor-Locke, Catrine; Zhao, Pei; Hu, Gang
    Objective: To examine the joint association of birth weight and physical activity/sedentary time with childhood obesity in 12 countries. Methods: A cross-sectional study of 5,088 children aged 9 to 11 years was conducted. Birth weight was recalled by parents or guardians. Moderate-to-vigorous physical activity (MVPA) and sedentary behavior were objectively measured using accelerometry. Results: The association of birth weight with the odds of obesity, central obesity, and high body fat was significant among children with either low MVPA or high sedentary time but not among children with either high MVPA or low sedentary time. In comparison with children with normal birth weight and high MVPA, children with high birth weight and low MVPA showed 4.48- to 5.18-fold higher odds of obesity, central obesity, and high body fat; children with normal birth weight and low MVPA showed 3.00- to 3.30-fold higher odds of obesity, central obesity, and high body fat, and children with high birth weight and high MVPA showed 1.16- to 1.68-fold higher odds of obesity, central obesity, and high body fat. Conclusions: High MVPA is more important than high birth weight as a correlate of obesity in children
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    Proportion of children meeting recommendations for 24-hour movement guidelines and associations with adiposity in a 12-country study
    (2016) Blanca, Roman-Viñas; Chaput, J-P.; Katzmarzyk, Peter T.; Fogelholm, Mikael; Lambert, Estelle V.; Maher, Carol; Maia, Jose; Olds, Timothy; Onywera, Vincent; Sarmiento, Olga L.; Standage, Martyn; Catrine, Tudor-Locke; Tremblay, Mark S.
    Background: The Canadian 24-h movement guidelines were developed with the hope of improving health and future health outcomes in children and youth. The purpose of this study was to evaluate adherence to the 3 recommendations most strongly associated with health outcomes in new 24-h movement guidelines and their relationship with adiposity (obesity and body mass index z-score) across countries participating in the International Study of Childhood Obesity, Lifestyle and the Environment (ISCOLE). Methods: Cross-sectional results were based on 6128 children aged 9–11 years from the 12 countries of ISCOLE. Sleep duration and moderate-to-vigorous physical activity (MVPA) were assessed using accelerometry. Screen time was measured through self-report. Body weight and height were measured. Body mass index (BMI, kg ·m−2) was calculated, and BMI z-scores were computed using age- and sex-specific reference data from the World Health Organization. Obesity was defined as a BMI z-score > +2 SD. Meeting the overall 24-h movement guidelines was defined as: 9 to 11 h/night of sleep, ≤2 h/day of screen time, and at least 60 min/day of MVPA. Age, sex, highest parental education and unhealthy diet pattern score were included as covariates in statistical models. Associations between meeting vs. not meeting each single recommendation (and combinations) with obesity were assessed with odds ratios calculated using generalized linear mixed models. A linear mixed model was used to examine the differences in BMI z-scores between children meeting vs. not meeting the different combinations of recommendations. Results: The global prevalence of children meeting the overall recommendations (all three behaviors) was 7%, with children from Australia and Canada showing the highest adherence (15%). Children meeting the three recommendations had lower odds ratios for obesity compared to those meeting none of the recommendations (OR = 0.28, 95% CI 0.18–0.45). Compared to not meeting the 24-h movement recommendations either independently or combined, meeting them was significantly associated with a lower BMI z-score. Whenever the MVPA recommendation was included in the analysis the odds ratios for obesity were lower.
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    Relationship between soft drink consumption and obesity in 9–11 years old children in a multi-national study
    (MDPI, 2016) Katzmarzyk, Peter T.; Broyles, Stephanie T.; Champagne, C.M.; Chaput, J-P.; Fogelholm, Mikael; Gang, Hu; Kuriyan, Rebecca; Kurpad, Anura; Lambert, Estelle V.; Jose, maia; Matsudo, Victor; Timothy, Olds; Onywera, Vincent; Sarmiento, Olga L.; Standage, Martyn; Tremblay, Mark S.; Catrine, Tudor-Locke; Zhao, Pei
    The purpose of this study was to determine the association between regular (sugar containing) and diet (artificially sweetened) soft drink consumption and obesity in children from 12 countries ranging in levels of economic and human development. The sample included 6162 children aged 9–11 years. Information on soft drink consumption was obtained using a food frequency questionnaire. Percentage body fat (%BF) was estimated by bio-electrical impedance analysis, body mass index (BMI) z-scores were computed using World Health Organization reference data, and obesity was defined as a BMI > +2 standard deviations (SD). Multi-level models were used to investigate trends in BMI z-scores, %BF and obesity across categories of soft drink consumption. Age, sex, study site, parental education and physical activity were included as covariates. There was a significant linear trend in BMI z-scores across categories of consumption of regular soft drinks in boys (p = 0.049), but not in girls; there were no significant trends in %BF or obesity observed in either boys or girls. There was no significant linear trend across categories of diet soft drink consumption in boys, but there was a graded, positive association in girls for BMI z-score (p = 0.0002) and %BF (p = 0.0001). Further research is required to explore these associations using longitudinal research designs
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    Sport s as means of preventing conflicts in institutions of higher learning
    (Kenyatta University, 2001) Onywera, Vincent; Mwisukha, A.; Njororai, W.W.S.
    Conflicts in Institutions of Higher Learning have been a disturbing phenomenon for many years. Colleges and Universities in many parts of East Africa have experienced problems associated with student riots and demonstration. Conflicts are known not only to be expensive to institutions of learning in terms of time, money and inconvenience, but also to the learners, sponsors and other stakeholders in education. A lot of effort has been put in place to eradicate this menace in the education sector, yet student unrest continues to be on the rise. More concerted effort needs to be put in place to eradicate this problem. Sport has certain unique values that can help learners enjoy their leisure time. Sport is a human activity that involves specific administrative organisation and a historical background of rules, which define the objective and limit the pattern of human behaviour. It involves competition or challenge and a definite outcome primarily determined by physical skill. Through participation in sports; students release emotions, experience success, socialize, control behaviour and affirm identity. Therefore if institutions of learning took sport seriously, putting rules and regulations to ensure that all students engaged in sport as an agent for change and development, cases of student riots and demonstrations might be controlled.