Discordance of international adiposity classifications in Australian boys and girls - The LOOK study

Background: Various charts based on body mass index (BMI) and per cent body fat (%BF) are used to classify childhood body composition but outcomes may vary.

Aim: The study investigated variation in incidences of childhood obesity as depicted by four classification charts.

Subjects and methods: BMI and DXA-derived %BF were assessed in 741 children. Incidences of overweight and obesity were compared between two BMI charts and two bioelectrical impedance (BIA)-based %BF charts.

Results: The International Obesity Task Force (IOTF)-adopted BMI chart designated 21%, 6% (boys), and 26%, 9% (girls) as overweight and obese, respectively. Corresponding figures using the USA CDC BMI chart were 27%, 11% (boys) and 27%, 12% (girls). Using a USA-derived %BF chart incidences were 17%, 2% (boys) and 21%, 8% (girls) and using a UK-derived %BF chart 51%, 24% (boys) and 53%, 36% (girls). Sensitivity of BMI varied according to the %BF reference chart.

Conclusions: In contrast to the BMI-based charts, there were considerable variations in depicted incidences of obesity between the %BF-based charts. These discordances were considered to result from previously reported variation within and between BIA and DXA %BF assessments underlying the charts. The present study highlights the need for valid, reliable, unchanging BIA and DXA procedures.

Girls challenging patriarchy through multimodal design and participation in online communities of practice.

This paper examines adolescent girls' multimodal design that challenges/resists patriarchy. Acts of uploading and multimodal design are discussed in terms of Bulter's theorisation of discursive performativity. The author suggests the girls employ a form of 'linguistic agency' or 'discursive agency' that allows them to make use of a wide range of multimodal design practices often unavailable in print dominated middle years classrooms. The girls in the study were involved in a set of relationships over time, both inside and outside of school in virtual and real time communities of practice. As a result, they engaged with particular areas of curricular knowledge differently than boys. The findings suggest that within online communities of practice, new contexts emerge where adolescent girls can contest the discourses of patriarchal power.

Tennis playing initiated before puberty leads to greater skeletal benefits in peri-pubertal boys than girls when training is maintained

Introduction: The purpose of the study was to compare the exercise-induced changes in bone mass and geometry between boys and girls.

Methods: Eighty competitive tennis players (43 boys, 37 girls) aged 7–19 years participated. Pubertal status was self-assessed using Tanner stages (TS 1–5). The dominant and nondominant humeri were compared for DXA-derived bone mass (BMC) and MRI-derived bone geometry [total bone area (TA), medullary area (MA) and cortical bone area (CA)].

Results/Discussion: Exercise-induced side-to-side differences in BMC, TA and CA were significant from TS1 to 5 in boys and girls (p < 0.06). Pre-pubertal (TS1) girls and boys show similar side-to-side difference in BMC after adjustment for training volume (19% vs. 15%, ns). Similar findings were found forTA and CA. In contrast, during puberty (TS2-4) boys displayed greater side-to-side differences than girls for BMC (27% vs. 18%, p < 0.05), TA (13–15% vs. 8%, p < 0.05) and CA (32% vs. 20%, p < 0.01), even after adjustment for tennis history. Girls partly compensated for the lack of an exercise-induced increase in bone size by a reduction of the medullary cavity on the dominant side (−5.5 to −13%, p < 0.05). In post-puberty (TS 5 or postmenarche), the size of the medullary cavity remained smaller on the dominant side in girls (−5% to −9%, p = 0.1–0.05??) whereas no such reduction was observed in boys.

Conclusion: Regular exercise initiated before puberty and maintained throughout puberty leads to greater skeletal benefits in peri-pubertal boys than girls for bone mass and bone size, two of the major determinants of bone strength.

'Girls talking about girls' issues' : the importance of girls-only health and physical education in promoting well-being

Recognition of the important role schools play in the promotion of student well-being can be seen in the growing number of policies and programs being implemented in schools across Australia. This paper reports on some initial data from focus group interviews with Year 9 and 10 girls involved in the pilot of a health and physical activity intervention designed to connect them to their local community and reconnect them with their school and their peers. The aim of the program was to build connectedness and resilience by engaging young women in non-traditional physical activities whilst providing them with a sound understanding of health issues relevant to adolescent girls. Situated in a relatively isolated rural community 200 kilometres south-east of Melbourne the program was overwhelmingly delivered by regional and local agencies in conjunction with the local secondary school. The intervention was built on a partnerships model designed with the purpose of increasing participation and access for young women whilst building a sustainable program run in partnership between the school and local agencies and services. The initial data from this pilot indicates the program is having a positive impact on the young women's sense of self and their bodies, their relationships with their peers and in reducing bullying behaviour amongst the girls. However, the data raises some important questions around the adequacy of school-based health education, and the sustainability of approaches designed to be delivered by outside agencies rather than classroom teachers.

Do boys do the atopic march while girls dawdle?

Background
The atopic march hypothesis suggests that infants with eczema are at increased risk of asthma. Others argue that eczema is not a risk factor for asthma unless there is also sensitization or early wheezing.
Objective
To examine the role of infantile eczema as a predictor of risk of childhood asthma, while allowing for the effects of early wheeze, sensitization, and sex, both as independent effects and possible effect modifiers.
Methods
A total of 620 infants with a family history of allergic disease was recruited. Eczema and wheeze was prospectively documented to 2 years of age. Sensitization was determined by skin prick tests at 6, 12, and 24 months to 6 common food and inhalant allergens. Interviews were conducted at 6 and 7 years to ascertain current asthma.
Results
Sufficiently complete data were available for 403 children. Eczema within the first 2 years of life was clearly associated with an increased risk of childhood asthma in boys (adjusted odds ratio, 2.45; 95% CI, 1.31-4.46) but not in girls (odds ratio, 0.88; 95% CI, 0.43-1.77; P for interaction = .031) even with adjustment for the effects of early allergic sensitization and wheeze. If these relationships are causal, an intervention to prevent eczema in boys might reduce the incidence of childhood asthma by as much as 28%.
Conclusion
Eczema in the first 2 years of life is associated with an increased risk of childhood asthma in boys, but there is no evidence of this in girls.

Adolescent girls in physical education and sport : an analysis of influences on participation

This study investigates the influences on participation in physical activity of thirty adolescent girls from a metropolitan secondary school in Victoria. It seeks to understand how they perceived, experienced and explained their involvement or non involvement in both competitive and non competitive physical activity during four years of their secondary schooling. Participants experienced physical education as both a single sex group in Years 7 and 9 and a coeducational group in Years 8 and 10. They were exposed to a predominantly competitive curriculum in Years 7 to 9 and a less structured, more social, recreational program in Year 10. These experiences enabled them to compare the differences between class structures and activity programs and identify the significant issues which impacted on their participation. Large Australian population studies have revealed that fewer girls participated in sport and regular physical activity than boys. An important consequence is that girls miss out on the health benefits associated with participating in physical activity. Other research has found adolescence is the time that girls drop out of competitive sport. However, an important issue is whether girls who drop out of competitive sport cease to be involved in any physical activity. There are some studies which have reported good participation rates by adolescent girls in non competitive, recreational forms of physical activity and the possibility exists that they may drop out of competitive and into non competitive physical activity. This study primarily utilises a qualitative approach in contrast to previous studies which have largely relied upon the use of surveys and questionnaires. Whilst quantitative research has provided useful information about the bigger picture, there are limitations caused by reliance on the researchers' own interpretations of the data. Additionally there is no opportunity for any clarification and explanation of findings and trends by the respondents themselves. The current study utilized qualitative individual and collective interviews in three stages. Questions were asked in the broad areas of coeducation and single sex classes, preferences for competitive or recreational activity and body image issues. Some quantitative information focusing on nature and extent of current activity patterns was also gathered in the first stage. Thirty Year 10 girls participated in individual first interviews. Nine selected girls then took part in the second (individual) and third (collective) interview stages. Results revealed three groups based on the nature of physical activity involvement: [1] competitive activity group, [2] social activity group and [3] transition group. The transition group represented those who were in the process of withdrawing from competitive sport to take up more non competitive, recreational activity. The most significant difference between groups was skill level. On the whole those entering adolescence with the highest skill levels, such as those in the competitive group, were the most confident and relished competing against others. The social group was low in skill and confidence and had predominantly negative experiences in physical education and sport because their deficiencies were plainly visible to all. Similarly, a lack of skill improvement relative to those of 'better performers' affected the interest and confidence levels of those in the transition group. Boys' domination in coeducational classes through verbal and physical intimidation of the less competent and confident girls and exclusion of very competent girls was a major issue. Social and transition group members demonstrated compliance with boys' power by hanging back and sitting out of competitive activities. Conversely, the competitive group resisted boy's attempts to dominate but had to work hard to demonstrate their athletic capabilities in order to do so. Body image issues such as the skimpy physical education and sport uniform along with body revealing activities such as swimming and gymnastics, heightened feelings of self-consciousness and embarrassment for most girls. When strategies were adopted by social and transition group members to avoid any body exposure or physical humiliation, participation levels were subsequently affected. However, where girls felt confident about their physical abilities and body image, they were able to ignore their unflattering uniforms and thus participation was unaffected. Specific teaching practices such as giving more attention to boys, for example by segregating the sexes in mixed classes to focus attention on boys, reinforced stereotypical notions of gender and contributed to the inequities for girls in physical education. The competitive group were frustrated with having to prove themselves as capable as boys in order to receive greater teacher attention. The transition group rejected teacher's attempts to coerce them into participating in the inter school sports program. The social group believed that teachers viewed and treated them less favourably than others because of their limited skills. Girls were not passive in the face of these obstacles. Rather than give up physical activity they disengaged from competitive sport and took up other forms of activity which they had the confidence to perform. These activity choices also reflected their expanding social interests such as spending time with male and female friends outside school and increased demands on their time by study and part time work commitments. This study not only highlighted the diversity and complexity of attitudes and behaviours of girls towards physical activity but also demonstrated that they display agency in making conscious, sensible decisions about their physical activity choices. Plain Language Summary of Thesis Adolescent girls in physical education and sport; An analysis of influences on participation by Julia Whitty Submitted for the degree of Master of Applied Science Deakin University Supervisor: Dr Judy Ann Jones This study investigates the influences on participation in physical activity of thirty adolescent girls from a metropolitan secondary school in Victoria in order to understand how girls' perceived, experienced and explained their involvement or non involvement in both competitive and non competitive physical activity. Qualitative individual and collective interviews were conducted. Questions focussed on attitudes about coeducation and single sex classes, preferences for competitive or recreational activity and feelings about body image. Some quantitative information about the nature and extent of current activity patterns was also gathered in the first stage. Thirty Year 10 girls participated in individual first interviews. Nine selected girls then took part in the second (individual) and third (collective) interview stages. Results revealed three clearly different groups based on the nature of physical activity involvement (1) Competitive, (2) Social and (3) Transition (those in the process of withdrawing from competitive sport to take up more non competitive, recreational activity). The major difference between groups was skill level. Those entering adolescence with the highest skill levels were more competent and confident in the coeducational and competitive sport setting. Other significant issues included boys' domination, body image and teaching behaviours and practices.

Patterns of physical activity for adolescent girls in Fiji and Tonga

Behavioural patterns are determined in part by sociocultural factors such as values, expected behaviours and sociopolitical organisation. This paper presents the patterns of physical activity reported by Tongan and Fijian females aged 12-18 years and possible explanations for these patterns. The paper draws on interviews conducted in a wider study of adolescents patterns of eating, physical activity and body size in Tonga, Fiji, New Zealand and Australia. The study examined sociocultural factors that could promote or protect against obesity from the perspective of adolescents in order to develop culturally-appropriate strategies for healthy lifestyles. Twenty four indigenous Fijian and 24 Tongan females aged 12-18 years were interviewed by females who were fluent in participants first languages. Researchers from Australia, Tonga and Fiji analysed the data separately and then together in order to capture cultural nuances and enhance cultural validity. This analysis revealed similarities and differences in both cultural groups. Limitations to physical activity identified by Tongan and Fijian girls included the time spent in household chores and parental restrictions.Fijian girls also identified concern about personal safety as a constraint. These findings are examined in relation to sociocultural factors that appear to limit opportunities for young females to be physically active.

A comparison of the socio-cultural influences on body size perceptions and values among European Australian and Indigenous Fijian adolescent girls

Western women are experiencing increases in the prevalence of overweight and obesity despite valuing slimness as ideal and equating thinness with attractiveness and beauty. Pacific populations are also experiencing high prevalence rates of overweight and obesity. A lage body size, however, has many positive connotations among pacific populations that stem from rich cultural practices such as feasts and deliberate fattening of women. There appears to be many sociocultural factors however, such as images of the slim ideal portrayed in Western media, influencing body image concerns that are shared between the two groups. A qualitative study involving semi-structured interviews was conducted to examine and compare the sociocultural influences on body size perceptionsand values. Participants include 16 European Australian and 16 Indigenous Fijian adolescent girls aged between 15 and 17 years. Inductive thematic analysis and analytical induction were qualitativemethods employed to facilitate interpretation of the findings. Preliminary findings suggest that Fijian adolescent girls experience greater conflict than European Australian girls about the desired body size endorsed in their community. Results also suggest that Indigenous Fijian girls place less importance than Australian girls on manipulating their body to achieve a specific ideal. Specific results of this study are reviewed and recommendations for future research are discussed.