The dietary, physical activity and sedentary behaviours of Victorian regional secondary school students

The aim of this study was to investigate the dietary, physical activity and sedentary behaviours of adolescents from four secondary schools in Warrnambool, regional Victoria. In 2004, a random sample of students (n=712), stratified by school year level, was generated from school enrolment databases and 443 students completed a lifestyle questionnaire. Twenty per cent of students were physically active for 60 minutes or more per day; 28 per cent used electronic media in free time for a maximum of two hours per day. Only seven per cent of students met these two Australian physical activity recommendations. Fruit, vegetables and dairy products were consumed every day by 39 per cent, 40 per cent and 71 per cent of students respectively; three serves per day of each of these foods are recommended for Australian adolescents. Compared with boys, girls were less physically active (p<0.001), consumed more fruit (p=0.011) and vegetables (p<0.001), but fewer dairy products (p<0.024). Seventeen per cent of students were overweight or obese; these students were less physically active than normal weight peers (p<0.018). The dietary, physical and sedentary behaviours of regional Victorian secondary school students in this study were inadequate when compared with Australian recommendations. Dietary and physical activity habits are still evolving in adolescence and unhealthy habits can still be changed.

Overweight and obesity in Australia: the 1999-2000 Australian Diabetes, Obesity and Lifestyle Study (AusDiab)

Objective:
To measure the prevalence of obesity in Australian adults and to examine the associations of obesity with socioeconomic and lifestyle factors.

Design:
AusDiab, a cross-sectional study conducted between May 1999 and December 2000, involved participants from 42 randomly selected districts throughout Australia.

Participants:
Of 20 347 eligible people aged > 25 years who completed a household interview, 11 247 attended the physical examination at local survey sites (response rate, 55%).

Main outcome measures:
Overweight and obesity defined by body mass index (BMI; kg/m2) and waist circumference (cm); sociodemographic factors (including smoking, physical activity and television viewing time).

Results:
The prevalence of overweight and obesity (BMI > 25.0 kg/m2; waist circumference > 80.0 cm [women] or > 94.0 cm [men]) in both sexes was almost 60%, defined by either BMI or waist circumference. The prevalence of obesity was 2.5 times higher than in 1980. Using waist circumference, the prevalence of obesity was higher in women than men (34.1% v 26.8%; P < 0.01). Lower educational status, higher television viewing time and lower physical activity time were each strongly associated with obesity, with television viewing time showing a stronger relationship than physical activity time.

Conclusions:
The prevalence of obesity in Australia has more than doubled in the past 20 years. Strong positive associations between obesity and each of television viewing time and lower physical activity time confirm the influence of sedentary lifestyles on obesity, and underline the potential benefits of reducing sedentary behaviour, as well as increasing physical activity, to curb the obesity epidemic.

A culturally appropriate diet and lifestyle intervention can successfully treat the components of metabolic syndrome in female Pakistani immigrants residing in Melbourne, Australia

This study was designed to test the effectiveness of a culturally appropriate diet and lifestyle intervention to treat metabolic syndrome in female Pakistani immigrants residing in Melbourne, Australia. Forty Pakistani women with metabolic syndrome (aged 20-50 years) completed a 12-week culturally appropriate diet and exercise program. Results indicate that, before intervention, participants were sedentary, taking 4000 ± 22.6 steps per day, and had an obese-classified body mass index (BMI) of 29.2 ± 0.46 kg/m2 (BMI was categorized in accordance with guidelines specifically designed for Asians) and high waist circumference of 132 ± 25.95 cm. Participants were hypertensive (systolic, 135 ± 1.3 mm Hg; diastolic, 86 ± 0.68 mm Hg), were dyslipidemic (total cholesterol, 6.8 ± 0.15 mmol/L; triglycerides, 2.9 ± 0.09 mmol/L), and had elevated blood glucose (6.4 ± 0.33 mmol/L) and fasting blood insulin (45 ± 6.3 μU/mL) levels. After the 12-week culturally appropriate intervention, activity increased (8600 ± 596.7 steps per day, P < .05); and BMI (27.8 ± 0.45 kg/m2), blood pressure (systolic, 125 ± 1.4 mm Hg; diastolic, 80 ± 0.6 mm Hg), cholesterol (5.5 ± 0.1 mmol/L), blood glucose (5.9 ± 0.33 mmol/L), and blood insulin (24.14 ± 1.8 μU/mL) levels were all significantly reduced (P < .05). This study revealed that the Pakistani female migrants who had metabolic syndrome and its components can successfully be treated via a culturally appropriate diet and lifestyle intervention. The success of the current program raises the possibility that other high-risk ethnic groups can also be treated with a culturally appropriate program.

Breaks in sedentary time

OBJECTIVE--Total sedentary (absence of whole-body movement) time is associated with obesity, abnormal glucose metabolism, and the metabolic syndrome. In addition to the effects of total sedentary time, the manner in which it is accumulated may also be important. We examined the association of breaks in objectively measured sedentary time with biological markers of metabolic risk.

RESEARCH DESIGN AND METHODS--Participants (n = 168, mean age 53.4 years) for this cross-sectional study were recruited from the 2004-2005 Australian Diabetes, Obesity and Lifestyle study. Sedentary time was measured by an accelerometer (counts/[minute^-1] < 100) worn during waking hours for seven consecutive days. Each interruption in sedentary time (counts/min [greater than or equal to] 100) was considered a break. Fasting plasma glucose, 2-h plasma glucose, serum triglycerides, HDL cholesterol, weight, height, waist circumference, and resting blood pressure were measured. MatLab was used to derive the breaks variable; SPSS was used for the statistical analysis.

RESULTS--Independent of total sedentary time and moderate-to-vigorous intensity activity time, increased breaks in sedentary time were beneficially associated with waist circumference (standardized ß = -0.16, 95% CI -0.31 to -0.02, P = 0.026), BMI (ß = -0.19, -0.35 to -0.02, P = 0.026), triglycerides (ß = -0.18, -0.34 to -0.02, P = 0.029), and 2-h plasma glucose (ß = -0.18, -0.34 to -0.02, P = 0.025).

CONCLUSIONS--This study provides evidence of the importance of avoiding prolonged uninterrupted periods of sedentary (primarily sitting) time. These findings suggest new public health recommendations regarding breaking up sedentary time that are complementary to those for physical activity.

Glucose indices, health behaviors, and incidence of diabetes in Australia: the Australian diabetes, obesity and lifestyle study (AusDiab)

OBJECTIVE--We examined the associations of objectively measured sedentary time and physical activity with continuous indexes of metabolic risk in Australian adults without known diabetes.

RESEARCH DESIGN AND METHODS--An accelerometer was used to derive the percentage of monitoring time spent sedentary and in light-intensity and moderate-to-vigorous-intensity activity, as well as mean activity intensity, in 169 Australian Diabetes, Obesity and Lifestyle Study (AusDiab) participants (mean age 53.4 years). Associations with waist circumference, triglycerides, HDL cholesterol, resting blood pressure, fasting plasma glucose, and a clustered metabolic risk score were examined.

RESULTS--Independent of time spent in moderate-to-vigorous-intensity activity, there were significant associations of sedentary time, light-intensity time, and mean activity intensity with waist circumference and clustered metabolic risk. Independent of waist circumference, moderate-to-vigorous-intensity activity time was significantly beneficially associated with triglycerides.

CONCLUSIONS--These findings highlight the importance of decreasing sedentary time, as well as increasing time spent in physical activity, for metabolic health.

Maternal self-efficacy regarding children's eating and sedentary behaviours in the early years : Associations with children's food intake and sedentary behaviours

Introduction. This cross-sectional study aimed to describe parents' views regarding self-efficacy to influence children's eating and sedentary behaviours at two time points in early childhood, and to examine associations between these views and children's eating and sedentary behaviours.

Methods. Mothers of 1-year (n=60) and 5-year-old children (n=80) were recruited through Maternal and Child Health Centres and kindergartens in Victoria, Australia. Mothers reported children's dietary intake, television viewing and perceptions of their self-efficacy regarding children's eating and sedentary behaviours.

Results. Overall, 5-year-old children consumed significantly more energy-dense food and drink and spent significantly more time viewing TV/DVD and video. Mothers of 1-year-olds were significantly more likely to report they felt confident to limit child's consumption of non-core foods/drinks, and to limit screen access (p<0.001). Measures of maternal self-efficacy were directly associated with 5-year-old children's water (p<0.05), and fruit and vegetable consumption (p<0.005), and with 1-year-old children's vegetable consumption (p<0.05), and were inversely associated with cordial and cake consumption (p<0.05). Maternal self-efficacy to limit viewing time was inversely associated with screen-time exposure in both age groups (p<0.01).

Conclusion. This study suggests that mother's self-efficacy regarding limiting non-core foods/drinks and limiting screen-time exposures may decline during the first few years of a child's life. Higher maternal self-efficacy was associated with children having more obesity protective eating and sedentary behaviours at both ages. Interventions to support the development of healthy lifestyle behaviours may be most effective if they target mothers' self-efficacy in these domains early in their child's life.

Emerging nutritional and lifestyle risk factors for bone health in young women: a mixed longitudinal twin study

Late adolescence and early adulthood are times of major behavioral transition in young women as they become more independent and make choices about lifestyle that will affect their long-term health. We prospectively evaluated nutritional and lifestyle factors in 566 15 30-year-old female twins participating in a mixed longitudinal study of diet and lifestyle.Twins completed 790 visits including questionnaires and measures of anthropometry. Nonparametric tests (chi-square, Mann-Whitney U, and Kruskal-Wallis; SPSS) were used to examine age-related differences in selected variables. Dietary calcium intake by short food frequency questionnaire was relatively low [511 (321,747)] mg/day (median, IQR; 60 % of estimated daily total) and did not vary significantly with age. The number of young women who reported ever consuming alcohol (12+ standard drinks ever) increased from 50 % under 18 years to 93 99 % for the 18+ age groups. Of those who consumed alcohol in the preceding year, monthly intake doubled from under 18 years (5.7, 3.9, 19.0 standard drinks; median, IQR) to 18+ years (12.0, 4.7, 26.0; P < 0.001) with the highest consumers being 21 23 and 27 29 years. At age 15 17 years, 14 % reported ever smoking and by age 27–29, 51 % had smoked (P = 0.002). Under the age of 20 years, average cigarette consumption in smokers was six cigarettes per day, increasing to ten above age 20 (P < 0.001). Participation in sporting activity decreased with age (P < 0.001): 47.5 % of 15–17-year-olds undertook 4 or more hour/week of sport, compared with 23.5 % at age 27–29 years. Conversely, sedentary behavior increased with age: 25.0 % of 15–17-year-olds reported 1 or less hour/week of exercise compared with 50.0 % at age 27–29 years. BMI increased with age (P = 0.011), from 21.3 (19.5, 23.6; median, IQR) in the youngest to 23.1 (21.5, 25.9) in the oldest. These highly significant changes in behavior in young women as they transitioned into independent adult living are predicted to impact adversely on bone and other health outcomes in later life. It is crucial to improve understanding of the determinants of these changes and to develop effective interventions to improve long-term health outcomes in young women.

Adherence to a lifestyle physical activity program: Trends over time and associations with processes of change and physical activity

Research on lifestyle physical activity interventions suggests that they help individuals meet the new recommendations for physical activity made by the Centers for Disease Control and Prevention (CDC) and the American College of Sports Medicine (ACSM). The purpose of this research was to describe the rates of adherence to two lifestyle physical activity intervention arms and to examine the association between adherence and outcome variables, using data from Project PRIME, a lifestyle physical activity intervention based on the transtheoretical model and conducted by the Cooper Institute of Aerobics Research, Dallas, Texas. Participants were 250 sedentary healthy adults, aged 35 to 70 years, primarily non-Hispanic White, and in the contemplation and preparation stages of readiness to change. They were randomized to a group (PRIME G) or a mail- and telephone-delivered condition (PRIME C). Adherence measures included attending class (PRIME G), completing a monthly telephone call with a health educator (PRIME C), and completing homework assignments and self-monitoring minutes of moderate- to vigorous physical activity (both groups). In the first results paper, adherence over time and between conditions was examined: Attendance in group, completing the monthly telephone call, and homework completion decreased over time, and participants in PRIME G were more likely to complete homework than those in PRIME C. Paper 2 aimed to determine whether the adherence measures predicted achievement of the CDC/ACSM physical activity guideline. In separate models for the two conditions, a latent variable measuring adherence was found to predict achievement of the guideline. Paper 3 examined the association between adherence measures and the transtheoretical model's processes of change within each condition. For both, participants who completed at least two thirds of the homework assignments improved their use of the processes of change more than those who completed less than that amount. These results suggest that encouraging adherence to a lifestyle physical activity intervention, at least among already motivated volunteers, may increase the likelihood of beneficial changes in the outcomes. ^

Effect of a lifestyle physical activity intervention on transtheoretical model variables

Purpose. To determine the effect a stage-based, lifestyle physical activity intervention has on Transtheoretical Model variables in a population of breast cancer survivors. ^ Methods. Sedentary breast cancer survivors (N=60) were randomized to either a standard care study condition or to a 6-month, 21-session intervention. The Transtheoretical Model variables stage of change, self-efficacy, decisional balance (pros and cons to exercise), and processes of change were measured at baseline, 3 months, and 6 months. ^ Results. Women in the lifestyle group had significantly higher self-efficacy than women in the standard care group (F=9.55, p=0.003). Although there was not a significant difference between the two groups for perceived pros of exercise, there was a significant difference between the groups for perceived cons of exercise. Women in the lifestyle group perceived significantly fewer cons of exercise at both 3 and 6 months compared with women in the standard care condition (F=5.416, p=0.025). Between baseline and the 6 month assessment, the intervention also had an effect on three of the processes of change, while seven of the processes were not significantly affected by the intervention. ^ Conclusions. Data from the pilot study suggest that a stage-based, lifestyle physical activity intervention has an effect on Transtheoretical Model variables, which have been shown to facilitate exercise adoption, and should be tested in a larger trial. ^

The association between number of homework assignments completed during a lifestyle physical activity intervention and scores on transtheoretical measures

An assumption of theory-based physical activity interventions is that active participation positively affects the theoretical constructs upon which the intervention is based. This assumption is rarely tested. This study assessed whether participation, defined as completion of homework, in a lifestyle physical activity intervention was associated with changes over 6 months in constructs the homework addressed: the behavioral and cognitive processes of change, self-efficacy, and decisional balance (the pros and cons). Participants were 244 sedentary adults aged 25 to 75 years. They completed an average of 12 of 20 homework assignments. Those completing at least two-thirds of the homework (n = 113) had greater changes in the theoretical constructs from pretest to posttest than those completing less (n = 90). Post-hoc analyses suggest that completing theory-based homework may impact the processes of change and self-efficacy in lifestyle physical activity interventions and, therefore, are warranted in future interventions.

Study protocol of European Fans in Training (EuroFIT) : a four-country randomised controlled trial of a lifestyle program for men delivered in elite football clubs

Funding The EuroFIT study is funded by the European Union’s Seventh Framework Program for research technological development and demonstration under Grant Agreement no: 602170. The Health Services Research Unit, University of Aberdeen, is core funded by the Chief Scientist Office of the Scottish Government Health Directorates.

The Influence of Age, Cardiorespiratory Fitness, Exercise and Sedentary Behaviours on Circulating Angiogenic Cells and Cell Surface Receptor Expression.

Cardiovascular disease (CVD) is the biggest killer of people in western civilisation. Age is a significant risk factor for the development for CVD, and treatments and therapies to address this increased risk are crucial to quality of life and longevity. Exercise is one such intervention which has been shown to reduce CVD risk. Age is also associated with endothelial dysfunction, reduced angiogenic capabilities, and reduced ability to repair the vessel wall. Circulating angiogenic cells (CACs) are a subset of circulating cells which assist in the repair and growth of the vasculature and in the maintenance of endothelial function. Reductions in these cells are observed in those with vascular disease compared to age-matched healthy controls. Exercise may reduce CVD risk by improvements in number and/or function of these CACs. Data was collected from human volunteers of various ages, cardiorespiratory fitness (CRF) levels and latent viral infection history status to investigate the effects of chronological age, CRF, viral serology and other lifestyle factors, such as sedentary behaviours and exercise on CACs. The levels of CACs in these volunteers were measured using four colour flow cytometry using various monoclonal antibodies specific to cell surface markers that are used to identify specific subsets of these CACs. In addition, the response to acute exercise of a specific subset of these CACs, termed ‘angiogenic T-cells’ (TANG) were investigated, in a group of well-trained males aged 20-40 years, using a strenuous submaximal exercise bout. Advancing age was associated with a decline in various subsets of CACs, including bone marrow-derived CD34+ progenitors, putative endothelial progenitor cells (EPCs) and also TANG cells. Individuals with a higher CRF were more likely to have higher circulating numbers of TANG cells, particularly in the CD4+ subset. CRF did not appear to modulate CD34+ progenitors or EPC subsets. Increasing sitting time was associated with reduction in TANG cells, but after correcting for the effects of fitness, sitting time no longer negatively affected the circulating number of these cells. Acute exercise was a powerful stimulus for increasing the number of TANG cells (140% increase), potentially through an SDF-1:CXCR4-dependent mechanism, but more studies are required to investigate this. Latent CMV infection was associated with higher number of TANG cells (CD8+), but only in 18-40 year old individuals, and not in an older age group (41-65 year old). The significance of this has yet to be understood. In conclusion, advancing age may contribute to increased CVD risk partly due to the observed reductions in angiogenic cells circulating in the peripheral compartment. Maintaining a high CRF may attenuate this CVD reduction by modulating TANG cell number, but potentially not CD34+ progenitor or EPC subsets. Acute exercise may offer a short window for vascular adaptation through the mobilisation of TANG cells into the circulation.

Television viewing time and 13-year mortality in adults with cardiovascular disease: data from the Australian Diabetes, Obesity and Lifestyle Study (AusDiab)

BACKGROUND: In the general population, excessive sedentary behaviour is associated with increased all-cause mortality. Few studies have examined this relationship in people with cardiovascular disease (CVD). Using a sample of people with CVD who were excluded from an analysis of the Australian Diabetes, Obesity and Lifestyle (AusDiab) study, we examined the relationship between sedentary behaviour and 13-year all-cause mortality.

METHODS: In the original AusDiab study, television viewing time was used as a marker of sedentary behaviour in 609 adults (≥45 years of age) with CVD. During 6,291 person-years of follow-up (median follow-up 13 years), there were 294 deaths (48% of sample). Using the time scale of attained age, the Cox proportional hazards model predicting all-cause mortality adjusted for sex, self-rated general health, leisure-time physical activity, smoking status, education, household income, body mass index, lipid levels, blood pressure, and diabetes mellitus was used.

RESULTS: Compared with a TV viewing time of <2hours per day, the fully adjusted hazard ratios for all-cause mortality were 1.18 (95% CI, 0.88 to 1.57) for ≥2 to <4hours per day and 1.52 (95% CI, 1.09 to 2.13) for >4hours per day.

CONCLUSIONS: Sedentary behaviour was associated with increased risk of all-cause mortality in people with CVD, independent of physical activity and other confounders. In addition to the promotion of regular physical activity, cardiac rehabilitation efforts which also focus on reducing sedentary behaviour may be beneficial.

A 30-month worksite-based lifestyle program to promote cardiovascular health in middle-aged bank employees: Design of the TANSNIP-PESA randomized controlled trial

Cardiovascular disease (CVD) is the leading cause of death worldwide. With atherosclerosis as the underlying cause for many CVD events, prevention or reduction of subclinical atherosclerotic plaque burden (SAPB) through a healthier lifestyle may have substantial public health benefits. The objective was to describe the protocol of a randomized controlled trial investigating the effectiveness of a 30-month worksite-based lifestyle program aimed to promote cardiovascular health in participants having a high or a low degree of SAPB compared with standard care. We will conduct a randomized controlled trial including middle-aged bank employees from the Progression of Early Subclinical Atherosclerosis cohort, stratified by SAPB (high SAPB n = 260, low SAPB n = 590). Within each stratum, participants will be randomized 1:1 to receive a lifestyle program or standard care. The program consists of 3 elements: (a) 12 personalized lifestyle counseling sessions using Motivational Interviewing over a 30-month period, (b) a wrist-worn physical activity tracker, and (c) a sit-stand workstation. Primary outcome measure is a composite score of blood pressure, physical activity, sedentary time, body weight, diet, and smoking (ie, adapted Fuster-BEWAT score) measured at baseline and at 1-, 2-, and 3-year follow-up. The study will provide insights into the effectiveness of a 30-month worksite-based lifestyle program to promote cardiovascular health compared with standard care in participants with a high or low degree of SAPB.