The impact of Curtin University's Activity, Food and Attitudes Program on physical activity, sedentary time and fruit, vegetable and junk food consumption among overweight and obese adolescents: A waitlist controlled trial

Background: To determine the effects of participation in Curtin University's Activity, Food and Attitudes Program (CAFAP), a community-based, family-centered behavioural intervention, on the physical activity, sedentary time, and healthy eating behaviours of overweight and obese adolescents. Methods: In this waitlist controlled clinical trial in Western Australia, adolescents (n = 69, 71% female, mean age 14.1 (SD 1.6) years) and parents completed an 8-week intervention followed by 12 months of telephone and text message support. Assessments were completed at baseline, before beginning the intervention, immediately following the intervention, and at 3-, 6-, and 12- months follow-up. The primary outcomes were physical activity and sedentary time assessed by accelerometers and servings of fruit, vegetables and junk food assessed by 3-day food records. Results: During the intensive 8-week intervention sedentary time decreased by −5.1 min/day/month (95% CI: −11.0, 0.8) which was significantly greater than the rate of change during the waitlist period (p = .014). Moderate physical activity increased by 1.8 min/day/month (95% CI: −0.04, 3.6) during the intervention period, which was significantly greater than the rate of change during the waitlist period (p = .041). Fruit consumption increased during the intervention period (monthly incidence rate ratio (IRR) 1.3, 95% CI: 1.10, 1.56) and junk food consumption decreased (monthly IRR 0.8, 95% CI: 0.74, 0.94) and these changes were different to those seen during the waitlist period (p = .004 and p = .020 respectively). Conclusions: Participating in CAFAP appeared to have a positive influence on the physical activity, sedentary and healthy eating behaviours of overweight and obese adolescents and many of these changes were maintained for one year following the intensive intervention. Trial Registration: Australia and New Zealand Clinical Trials Registry ACTRN12611001187932

Should public health interventions aimed at reducing childhood overweight and obesity be gender-focused?

<p>Abstract</p> <p>Background</p> <p>Overweight in childhood is a major public health concern that calls for immediate preventative action. An increasing number of reports suggest that gender specific approaches to prevention may be more effective. However, there is a paucity of information to guide gender-sensitive health promotion and population health interventions for the prevention of overweight in childhood. In the present study, we sought to determine gender-differentials in overweight and underlying behaviors, nutrition and physical activity, among pre-adolescents in Alberta, Canada, to inform the discussion on gender-focused interventions for chronic disease prevention.</p> <p>Methods</p> <p>In 2008, we surveyed 3421 grade five students and their parents of 148 randomly selected schools. Students completed the Harvard food frequency questionnaire, questions on physical activities, and had their height and weight measured. Parents completed questions on socio-economic background and child's lifestyle. We applied multilevel regression methods to assess gender differentials in overweight, nutrition and physical activity.</p> <p>Results</p> <p>Overall, the prevalence of overweight was slightly higher among boys (29.1%) than girls (27.9%) with more pronounced differences in towns and urban geographies. Boys reported to be much more physically active relative to girls (OR = 2.12, 95% CI: 1.73-2.60). Diets of boys, relative to those of girls, reportedly constituted more fat and were less likely to meet the recommendation of 6 daily servings of vegetables and fruits (OR = 0.81, 95% CI: 0.71-0.93).</p> <p>Conclusion</p> <p>Our findings confirm the existence of gender differences in physical activity and nutrition, and support gender-focused health promotion whereby priority is given to physical activity among girls and to healthy eating among boys.</p

The Formation of Collective Silk Balls in the Spider Mite Tetranychus urticae Koch

Tetranychus urticae is a phytophagous mite that forms colonies of several thousand individuals. These mites construct a common web to protect the colony. When plants become overcrowded and food resources become scarce, individuals gather at the plant apex to form a ball composed of mites and their silk threads. This ball is a structure facilitating group dispersal by wind or animal transport. Until now, no quantitative study had been done on this collective form of migration. This is the first attempt to understand the mechanisms that underlie the emergence and growth of the ball. We studied this collective behaviour under laboratory conditions on standardized infested plants. Our results show that the collective displacement and the formation of balls result from a recruitment process: by depositing silk threads on their way up to the plant apex, mites favour and amplify the recruitment toward the balls. A critical threshold (quorum response) in the cumulative flow of mites must be reached to observe the emergence of a ball. At the beginning of the balls formation, mites form an aggregate. After 24 hours, the aggregated mites are trapped inside the silk balls by the complex network of silk threads and finally die, except for recently arrived individuals. The balls are mainly composed of immature stages. Our study reconstructs the key events that lead to the formation of silk balls. They suggest that the interplay between mites' density, plant morphology and plant density lead to different modes of dispersions (individual or collective) and under what conditions populations might adopt a collective strategy rather than one that is individually oriented. Moreover, our results lead to discuss two aspects of the cooperation and altruism: the importance of Allee effects during colonization of new plants and the importance of the size of a founding group

Delivering in‐school interventions to improve dietary behaviours amongst 11‐ to 16‐year‐olds: A systematic review

Childhood obesity is a global health concern, which has both short‐and long‐term health consequences for the individual, and is a potential burden on health care services and the wider economy. The school environment is a setting where changes can be applied to dietary behaviours, as schools have direct and intensive contact with children. This systematic review evaluated school‐based interventions designed to improve dietary behaviours among adolescents (11‐to 16‐year‐olds). The aims were to review types of interventions delivered, dietary behaviours targeted, and interventions' effectiveness in improving dietary behaviour and associated intervention components. Twenty‐nine school‐based interventional studies with this population were identified for review. The data were synthesized by identifying and comparing individual studies' results, intervention components, and characteristics.Interventions appeared more effective when they involved peers, used educational media to deliver health messages, increased availability of healthy foods in school,and incorporated computer‐based individualized feedback with normative information on eating behaviours. A limitation of the review was the lack of description in cer-tain reviewed studies and the nonfeasibility of conducting a meta‐analysis owing to study heterogeneity. Future interventions with this population could consider including the aforementioned components, gender‐specific feedback, and both short‐and long‐term follow‐ups as change may not be apparent immediately and to determine if changes are sustained