Physical activity beliefs and behaviours among adults attempting weight control

Objective: To compare the frequency and duration of varying intensities of physical activity performed by adults trying to lose weight, avoid gaining weight and not actively trying to control their weight, and to compare these groups' beliefs about the physical activity they should perform.

Method: Random postal survey of 2500 Victorian adults selected from the Australian electoral roll (response rate=42%).

Measures: One-week physical activity recall (frequency and duration of walking, other moderate activity and vigorous activity), BMI (based on self-reported height and weight) and weight-control behaviour.

Results: At the time of the survey, 27% of respondents were actively trying to avoid gaining weight, 23.9% trying to lose weight and 49.1% undertaking no weight control. Respondents spent a mean time of 4.0 (±7.1) h walking, 5.5 (±7.9) h in moderate activity and 3.1(±5.9) h in vigorous activity during the week prior to the survey. Women trying to lose weight or avoid gaining weight engaged in vigorous activity more often than women not trying to control their weight. After adjusting for age, education and BMI, women trying to avoid gaining weight were 2.4 times more likely, and women trying to lose weight 2.5 times more likely, to have met current physical activity guidelines than women undertaking no weight control. On average, respondents believed they should spend 5.2 (±6.9) h walking, 6.5 (±8.2) h in moderate activity and 4.3 (±6.5) h in vigorous activity each week. Women trying to lose weight felt they should perform vigorous activity more often than other women. Weight-control behaviour was not associated with physical activity beliefs and behaviours of men.

Conclusion: Walking is a common activity among adults attempting weight control. However, many men and women do not fully recognize the value of moderate-intensity physical activity. Future efforts should be directed at promoting the role of moderate-intensity activity in weight control, particularly activity that can be performed outside of planned activity sessions.

Relationship of body condition score, live weight, stocking rate and grazing system to the mortality of Angora goats from hypothermia and their use in the assessment of welfare risks

Body condition scoring is widely used for sheep and cattle but the practice is included in only one Code of Practice for the welfare of goats in Australia. There is no published scientific evidence to support or defend its use in the assessment of welfare risks to farmed goats.

PROCEDURE: The significance of stocking rate, grazing system, body condition score (CS) and live weight were investigated in explaining the risk of mortality of individual and flocks of grazing Angora goats from hypothermia following a severe weather event in April. This event occurred 5 weeks after shearing the goats. Angora goats and Saxon Merino sheep were grazed alone, or mixed together in equal numbers at each of three stocking rates.

RESULTS: There was no mortality amongst Angora goats provided they grazed at the lowest stocking rate even when their CS was < or = 2.0. Mortality in flocks of Angora goats was most related to the CS reached during the preceding 2 months. For flocks of Angora goats there was no mortality at CS > or = 2.5 and mortality increased sharply at mean CS < 2.0. For individual Angora goats, mortality increased as CS declined and stocking rate and grazing combinations were additive in effect on mortality. Grazing with sheep increased mortality of Angora goats at higher stocking rates. The individual goat mortality rate was not dependent on individual plot effects suggesting that these results are applicable widely. Live weight loss was not related to mortality rates of goats once CS had been accounted for.
CONCLUSION: It was concluded that CS and stocking rate were highly significant determinants of welfare risk in Angora goats.

Inspection of drop-weight impact damage in woven CFRP laminates fabricated by different processes

The influence of manufacturing process on the drop-weight impact damage in woven carbon/epoxy laminates was inspected by visual observation, dyepenetrant X-ray technique, and optical microscopy observation. The MTM56/ CF0300 woven quasi-isotropic laminates were fabricated by two processes: the autoclave and the Quickstep processes. Quickstep^TM is a novel composite manufacturing process, which was designed for the out-of-autoclave production of high-quality composite parts at lower cost. It utilizes higher heat conduction of fluid other than gas to transfer heat to components, which results in much shorter cure cycles. The laminates cured by this fast heating process showed different impact failure modes from those cured by the conventional autoclave process. The residual indentation in the top side of the Quickstep-cured laminates had a bigger diameter, but a smaller depth at the same impact energy level. Dye-penetrant X-ray revealed more intense and connected impact damage regions in the autoclave-cured laminates. Optical micrography as a supplementary method showed less severe matrix damage in the quickstep-cured laminates indicating a more ductile property of the resin matrix cured at a faster heating rate.

The development of young adolescent boys' weight and shape concerns

This thesis' longitudinal study found that young adolescent boys' reported significant concerns with their weight and shape, particularly with respect to having a more muscular but lean physique. The strongest predictors of high body dissatisfaction, among boys, were poor perceptions of their sporting ability and low self-esteem. The portfolio examines the use of Single Session Therapy (SST) suggesting that SST can effectively reduce waiting lists and provide a single and complete intervention that is effective in approximately 50% of cases.

Physical activity, dietary change and weight control : a public health perspective

This study examined weight-control behaviour among Victorian adults, focusing specifically on physical activity and dietary fat-related behaviour and beliefs. It also explored barriers to changing diet and physical activity, and used common theories of behaviour change to identify factors that influence weight-control behaviour, weight change and perceived weight-control success.

Body image, muscularity and weight loss among people who attend gymnasiums

Biosocial models of weight loss and increased muscles were empirically tested among adult exercisers. Although women experienced greater body dissatisfaction, both genders engaged in potentially risky strategies to reach their body goals, ranging from the use of food supplements and steroids to bulimic behaviours and excessive exercise.

Novel hypothalamic genes involved in body weight regulation in Psammomys obesus

Focuses on the discovery, characterisation and validation of a gene in the brain, named FIT, that regulates body weight. When suppressed in rats, food intake is inhibited and body weight is reduced. FIT regulates both appetite and metabolic rate, and is therefore a new and exciting target for obesity therapy.

Body weight and weight loss : are health messages reaching their target?

Objective: To investigate lay peoples’ knowledge of health risks of overweight, accuracy of self-perception of body weight and perceived benefits of weight loss. Method: A nine item questionnaire was administered to a cross sectional survey of adults in metropolitan shopping centres, height and weight were measured. Results: Two hundred and nine (57% female) adults completed the survey. Thirty eight percent had a healthy BMI (18.5-24.9), 38% were overweight (BMI 25-29.9) and a further 22% were obese (BMI>30). However only 46% perceived themselves ‘overweight’, 50% considered themselves ‘just about right’ and 4% considered themselves ‘underweight’. Of those with a BMI of 25 or greater 28% considered their weight ‘just about right’. Over 80% thought ‘being overweight’ was ‘likely’ or ‘very likely’ to be a risk factor for cardiovascular disease, hypertension, diabetes and stroke; however 20% of overweight or obese individuals did not think their health would improve if they lost weight. Conclusion: A significant proportion of overweight or obese individuals do not accurately perceive their body weight and do not recognise the health advantages of weight loss despite recognising excess body weight as a risk factor for chronic diseases. Implications: Increasing the awareness of an individual’s BMI and promoting the benefits of modest weight loss maybe two underutilized strategies for population level weight control.

Personal, social and environmental correlates of healthy weight status amongst mothers from socioeconomically disadvantaged neighborhoods : findings from the READI study

Background

Socioeconomically disadvantaged mothers are at high risk of obesity, yet the aetiology of obesity in this group remains poorly understood. The aim of this study was to examine the perceived personal, social and physical environmental factors associated with resilience to obesity among mothers from socioeconomically disadvantaged neighbourhoods.
Methods

Survey data were provided by a cohort of 1840 women aged 18-46 years with dependent children (aged 0-18 years) from 40 urban and 40 rural socioeconomically disadvantaged neighbourhoods across Victoria, Australia. Mothers responded to a number of questions relating to personal, social and environmental influences on their physical activity and eating habits. Mothers' weight status was classified as healthy weight (BMI: 18.5-24.99), overweight (BMI: 25-29.99) or obese (BMI: 30+).
Results

Mothers' weight status was bivariably associated with factors from all three domains (personal, social and physical environmental). In a multivariable model, mothers' perceived ability to make time for healthy eating (OR = 1.34) and physical activity (OR = 1.11) despite family commitments, and the frequency with which families ate healthy low-fat foods with mothers (OR = 1.28) remained significantly positively associated with healthy weight status. The frequency with which families encouraged eating healthy low-fat foods remained negatively associated (OR = 0.81) with weight status; ie greater encouragement was associated with less healthy weight status.
Conclusions

Drawing on the characteristics of mothers resilient to obesity might assist in developing intervention strategies to help other mothers in socioeconomically disadvantaged neighbourhoods to manage their weight. Such strategies might focus on planning for and prioritising time for healthy eating and physical activity behaviours, and including family members in and encouraging family mealtimes.

Sociodemographic and behavioural correlates of weight status among women with children living in socioeconomically disadvantaged neighbourhoods

Objective: To investigate sociodemographic and behavioural characteristics associated with weight status among women with children living in socioeconomically disadvantaged neighbourhoods.
Methods and procedures: A total of 1680 women aged 18–46 years, living in socioeconomically disadvantaged neighbourhoods with dependent children (aged 0–18 years), provided self-report data on height and weight and a range of sociodemographic and behavioural (for example, dietary intake, physical activity and time spent sitting) characteristics.
Results: Half of the women were classified as having a healthy weight (body mass index=18.5–25). Bivariable ordinal logistic regression analyses indicated that a healthy weight status was associated with a range of sociodemographic and behavioural characteristics. In a multivariable model, a healthy weight status among women was associated with being younger and unmarried, speaking a language other than English at home, having a medium or high level of education, and a partner with a high level of education, having a high household income, spending more time engaged in leisure-time physical activity and less time spent sitting, and having a lower consumption of soft drink.
Discussion: The present findings highlight that a considerable proportion of women with children living in disadvantaged neighbourhoods manage to maintain a healthy weight. Acknowledging the cross-sectional nature of this study, strategies aimed at helping women with children in socioeconomically disadvantaged areas to maintain their weight should focus on increasing physical activity, and reducing sitting time and soft drink consumption.

Physical activity levels of normal-weight and overweight girls and boys during primary school recess

Objective: This study aimed to compare moderate-to-vigorous physical activity (MVPA) and vigorous physical activity (VPA) in normal-weight and overweight boys and girls during school recess.

Research Methods and Procedures: Four hundred twenty children, age 6 to 10 years, were randomly selected from 25 schools in England. Three hundred seventy-seven children completed the study. BMI was calculated from height and weight measurements, and heart rate reserve thresholds of 50% and 75% reflected children's engagement in MVPA and VPA, respectively.

Results: There was a significant main effect for sex and a significant interaction between BMI category and sex for the percent of recess time spent in MVPA and VPA. Normal-weight girls were the least active group, compared with overweight boys and girls who were equally active. Fifty-one boys and 24 girls of normal weight achieved the 40% threshold; of these, 30 boys and 10 girls exceeded 50% of recess time in MVPA. Eighteen overweight boys and 22 overweight girls exceeded the 40% threshold, whereas 8 boys and 8 girls exceeded the 50% threshold.

Discussion: Overweight boys were significantly less active than their normal-weight male counterparts; this difference did not hold true for girls. Even though nearly double the number of normal-weight children achieved the 40% of MVPA during recess compared with overweight children, physical activity promotion in school playgrounds needs to be targeted not only at overweight but at other health parameters, as 40 overweight children met the 40% MVPA target proposed for recess

Arterial compliance, blood pressure, plasma leptin, and plasma lipids in women are improved with weight reduction equally with a meat-based diet and a plant-based diet

Obesity, strongly associated with the risk for coronary heart disease (CHD), is becoming increasingly prevalent. This study was designed to establish first whether systemic arterial compliance (SAC), an index of arterial function, is improved with weight loss and second, whether cardiovascular risk factors that improve with weight loss are reduced equally with lean meat or with an equivalent amount of plant protein in the diet. Thirty-six women, mostly overweight or obess, aged 40 ± 9 years, were allocated nonrandomly to a 16-week parallel-design trial of two equienergetic diets designed to lead to weight loss, with one arm of the study emphasizing red meat and the other soybeans as the major protein source. Body weight, waist and hip circumference, and plasma lipids, glucose, insulin, and leptin levels were measured, and SAC was calculated from ultrasound measurement of aortic flow velocity and aortic root driving pressure. Subjects lost weight (9% of body weight in 16 weeks) and showed decreased plasma total and low-density lipoprotein (LDL) cholesterol (12% and 14%, P < .0001, respectively), triacylglycerol (17%, P < .05), and leptin (24%, P < .01) concentrations. However, lipoprotein(a) [Lp(a)] levels did not change significantly. Mean arterial pressure (MAP) decreased 7% and SAC increased 28% (P < .001 for both). However, only the decrease in arterial pressure correlated significantly with the reduction in the waist to hip ratio (WHR), and the improvement in SAC correlated inversely with the blood pressure reduction (P < .001 for both). Further, weight loss and the metabolic benefits of weight loss occurred equally with the meat-based and plant-based diets. We conclude that moderate weight loss in women leads to a substantial reduction in the cardiovascular risk, including SAC.