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Dive into the research topics where Rebecca L. Williams is active.

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Featured researches published by Rebecca L. Williams.


International Journal of Behavioral Nutrition and Physical Activity | 2015

Effectiveness of interventions targeting physical activity, nutrition and healthy weight for university and college students: A systematic review and meta-analysis

Ronald C. Plotnikoff; Sarah A. Costigan; Rebecca L. Williams; Melinda J. Hutchesson; Sarah G. Kennedy; Sara L. Robards; Jennifer Allen; Clare E. Collins; Robin Callister; John Germov

To examine the effectiveness of interventions aimed at improving physical activity, diet, and/or weight-related behaviors amongst university/college students. Five online databases were searched (January 1970 to April 2014). Experimental study designs were eligible for inclusion. Data extraction was performed by one reviewer using a standardized form developed by the researchers and checked by a second reviewer. Data were described in a narrative synthesis and meta-analyses were conducted when appropriate. Study quality was also established. Forty-one studies were included; of these, 34 reported significant improvements in one of the key outcomes. Of the studies examining physical activity 18/29 yielded significant results, with meta-analysis demonstrating significant increases in moderate physical activity in intervention groups compared to control. Of the studies examining nutrition, 12/24 reported significantly improved outcomes; only 4/12 assessing weight loss outcomes found significant weight reduction. This appears to be the first systematic review of physical activity, diet and weight loss interventions targeting university and college students. Tertiary institutions are appropriate settings for implementing and evaluating lifestyle interventions, however more research is needed to improve such strategies.


Current Nutrition Reports | 2016

What Are They Really Eating? A Review on New Approaches to Dietary Intake Assessment and Validation

Megan E. Rollo; Rebecca L. Williams; Tracy Burrows; Sharon I. Kirkpatrick; Tamara Bucher; Clare E. Collins

PurposeAssessing food and nutrient intakes is critical to evolving our understanding of diet-disease relationships and the refinement of nutrition guidelines to support healthy populations. The aims of this narrative review are to summarise recent advances in dietary assessment methodologies, with a particular focus on approaches using new technologies, as well as strategies to evaluate tools, and to provide directions for future research.Recent FindingsTechnology as a mode to assess dietary intake has gained momentum in recent years, with the development of image-based methods and wearable devices, as well as the emergence of online methods of administering traditional paper-based approaches to dietary assessment. At the same time, there have been advances in the development of dietary biomarkers to evaluate measures of self-reported dietary intake. Common biomarkers, such as plasma carotenoids and red blood cell fatty acids, are still being utilised with new markers including urinary markers of sugar or wholegrain intake, skin carotenoids as a measure of fruit and vegetable intake. As well, the field of metabolomics shows promise.SummaryChallenges remain in dietary intake assessment, and further efforts are required to refine and evaluate methods so that we can better understand diet-disease relationships and inform guidelines and interventions to promote health.


Diabetes, Metabolic Syndrome and Obesity: Targets and Therapy | 2016

eHealth technologies to support nutrition and physical activity behaviors in diabetes self-management

Megan E. Rollo; Elroy J. Aguiar; Rebecca L. Williams; Katie Wynne; Michelle Kriss; Robin Callister; Clare E. Collins

Diabetes is a chronic, complex condition requiring sound knowledge and self-management skills to optimize glycemic control and health outcomes. Dietary intake and physical activity are key diabetes self-management (DSM) behaviors that require tailored education and support. Electronic health (eHealth) technologies have a demonstrated potential for assisting individuals with DSM behaviors. This review provides examples of technologies used to support nutrition and physical activity behaviors in the context of DSM. Technologies covered include those widely used for DSM, such as web-based programs and mobile phone and smartphone applications. In addition, examples of novel tools such as virtual and augmented reality, video games, computer vision for dietary carbohydrate monitoring, and wearable devices are provided. The challenges to, and facilitators for, the use of eHealth technologies in DSM are discussed. Strategies to support the implementation of eHealth technologies within practice and suggestions for future research to enhance nutrition and physical activity behaviors as a part of broader DSM are provided.


International Journal of Molecular Sciences | 2016

Diet Quality and Cancer Outcomes in Adults: A Systematic Review of Epidemiological Studies

Jennifer Potter; Leanne Brown; Rebecca L. Williams; Julie Byles; Clare E. Collins

Dietary patterns influence cancer risk. However, systematic reviews have not evaluated relationships between a priori defined diet quality scores and adult cancer risk and mortality. The aims of this systematic review are to (1) describe diet quality scores used in cohort or cross-sectional research examining cancer outcomes; and (2) describe associations between diet quality scores and cancer risk and mortality. The protocol was registered in Prospero, and a systematic search using six electronic databases was conducted through to December 2014. Records were assessed for inclusion by two independent reviewers, and quality was evaluated using a validated tool. Sixty-four studies met inclusion criteria from which 55 different diet quality scores were identified. Of the 35 studies investigating diet quality and cancer risk, 60% (n = 21) found a positive relationship. Results suggest no relationship between diet quality scores and overall cancer risk. Inverse associations were found for diet quality scores and risk of postmenopausal breast, colorectal, head, and neck cancer. No consistent relationships between diet quality scores and cancer mortality were found. Diet quality appears to be related to site-specific adult cancer risk. The relationship with cancer mortality is less conclusive, suggesting additional factors impact overall cancer survival. Development of a cancer-specific diet quality score for application in prospective epidemiology and in public health is warranted.


Appetite | 2016

Energy homeostasis and appetite regulating hormones as predictors of weight loss in men and women

Rebecca L. Williams; Lisa Wood; Clare E. Collins; Philip J. Morgan; Robin Callister

Sex differences in weight loss are often seen despite using the same weight loss program. There has been relatively little investigation of physiological influences on weight loss success in males and females, such as energy homeostasis and appetite regulating hormones. The aims were to 1) characterise baseline plasma leptin, ghrelin and adiponectin concentrations in overweight and obese males and females, and 2) determine whether baseline concentrations of these hormones predict weight loss in males and females. Subjects were overweight or obese (BMI 25-40 kg/m(2)) adults aged 18-60 years. Weight was measured at baseline, and after three and six months participation in a weight loss program. Baseline concentrations of leptin, adiponectin and ghrelin were determined by enzyme-linked immunosorbent assay (ELISA). An independent t-test or non-parametric equivalent was used to determine any differences between sex. Linear regression determined whether baseline hormone concentrations were predictors of six-month weight change. Females had significantly higher baseline concentrations of leptin, adiponectin and unacylated ghrelin as well as ratios of leptin:adiponectin and leptin:ghrelin. The ratio of acylated:unacylated ghrelin was significantly higher in males. In males and females, a higher baseline concentration of unacylated ghrelin predicted greater weight loss at six months. Additionally in females, higher baseline total ghrelin predicted greater weight loss and a higher ratio of leptin:ghrelin predicted weight gain at six months. A higher pre-weight-loss plasma concentration of unacylated ghrelin is a modest predictor of weight loss success in males and females, while a higher leptin:ghrelin ratio is a predictor of weight loss failure in females. Further investigation is required into what combinations and concentrations of these hormones are optimal for weight loss success.


Nutrients | 2016

The Diet Quality of Competitive Adolescent Male Rugby Union Players with Energy Balance Estimated Using Different Physical Activity Coefficients

Tracy Burrows; Simon K. Harries; Rebecca L. Williams; Cheryl Lum; Robin Callister

Objectives: The aims of the current study were to comprehensively assess the dietary intakes and diet quality of a sample of Australian competitive adolescent rugby union players and compare these intakes with National and Sports Dietitians Association (SDA) Recommendations for adolescent athletes. A secondary aim investigated applying different physical activity level (PAL) coefficients to determine total energy expenditure (TEE) in order to more effectively evaluate the adequacy of energy intakes. Design: Cross-sectional. Methods: Anthropometrics and dietary intakes were assessed in 25 competitive adolescent male rugby union players (14 to 18 years old). Diet was assessed using the validated Australian Eating Survey (AES) food frequency questionnaire and diet quality was assessed through the Australian Recommended Food Score. Results: The median dietary intakes of participants met national recommendations for percent energy (% E) from carbohydrate, protein and total fat, but not carbohydrate intake when evaluated as g/day as proposed in SDA guidelines. Median intakes of fibre and micronutrients including calcium and iron also met national recommendations. Overall diet quality was classified as ‘good’ with a median diet quality score of 34 (out of a possible 73); however, there was a lack of variety within key food groups including carbohydrates and proteins. Non-core food consumption exceeded recommended levels at 38% of the daily total energy intake, with substantial contributions from takeaway foods and sweetened beverages. A PAL coefficient of 1.2–1.4 was found to best balance the energy intakes of these players in their pre-season. Conclusions: Adolescent rugby players met the percent energy recommendations for macronutrients and attained an overall ‘good’ diet quality score. However, it was identified that when compared to specific recommendations for athletes, carbohydrate intakes were below recommendations and these players in their pre-season reported high consumption of non-core foods, particularly sugar sweetened drinks and low intakes of vegetables.


European Journal of Clinical Nutrition | 2016

Comparison of fruit and vegetable intakes during weight loss in males and females

Rebecca L. Williams; Lisa Wood; Clare E. Collins; Robin Callister

Background/Objectives:Globally, fruit and vegetable intakes are well below recommendations despite ample evidence to link insufficient intake with increased risk of overweight and obesity. Intakes of fruits and vegetables in the general population differ between males and females, and although there is growing evidence of intakes in men and women during weight loss, evidence that directly compares intakes in men and women during weight loss is lacking. This study aimed to identify any differences between males and females in fruit and vegetable intakes and plasma carotenoid concentrations during weight loss, and determine whether there is a relationship between any changes in fruit and vegetable intakes and weight change in both males and females.Subjects/Methods:Men and women (n=100; body mass index 25–40 kg/m2) aged 18–60 years were selected for the study. Dietary intake of fruits and vegetables was assessed using the Australian Eating Survey and fasting blood was collected to assess plasma carotenoids, which were determined by high-performance liquid chromatography.Results:There was little change in fruit or vegetable intakes during weight loss, although men tended to increase fruit intakes. Changes in intakes were influenced by baseline intakes, with males and females with the highest intakes at baseline reducing intakes. Males had better correlations between fruit and vegetable intakes and plasma carotenoid concentrations than females, and fruit and vegetable intakes during weight loss appear to predict weight loss for males but not females.Conclusions:Fruit and vegetable intake during weight loss does not appear to differ largely between males and females.


Nutrients | 2017

Diet Quality Scores of Australian Adults Who Have Completed the Healthy Eating Quiz

Rebecca L. Williams; Megan E. Rollo; Tracy L. Schumacher; Clare E. Collins

Higher scores obtained using diet quality and variety indices are indicators of more optimal food and nutrient intakes and lower chronic disease risk. The aim of this paper is to describe the overall diet quality and variety in a sample of Australian adults who completed an online diet quality self-assessment tool, the Healthy Eating Quiz. The Healthy Eating Quiz takes approximately five minutes to complete online and computes user responses into a total diet quality score (out of a maximum of 73 points) and then categorizes them into the following groups: ‘needs work’ (<33), ‘getting there’ (33–38), ‘excellent’ (39–46), or ’outstanding’ (47+). There was a total of 93,252 first-time respondents, of which 76% were female. Over 80% of respondents were between 16–44 years of age. The mean total score was 34.1 ± 9.7 points. Females had a higher total score than males (p < 0.001) and vegetarians had higher total scores than non-vegetarians (p < 0.001). Healthy eating quiz scores were higher in those aged 45–75 years compared to 16–44 years (p < 0.001). When comparing Socioeconomic Indices for Areas deciles, those most disadvantaged had a lower total score than those least disadvantaged (p < 0.001). Repeat measures showed that those who scored lowest (needs work) in their first completion increased their total score by 3.2 ± 7.4 at their second completion (p < 0.001). While the Healthy Eating Quiz data indicates that individuals receiving feedback on how to improve their score can improve their diet quality, there is a need for further nutrition promotion interventions in Australian adults.


Obesity Reviews | 2015

Effectiveness of weight loss interventions--is there a difference between men and women: a systematic review.

Rebecca L. Williams; Lisa Wood; Clare E. Collins; Robin Callister


Journal of Nutrition and Intermediary Metabolism | 2014

Plasma carotenoid levels as biomarkers of dietary carotenoid consumption: A systematic review of the validation studies

Tracy Burrows; Rebecca L. Williams; Megan E. Rollo; Lisa Wood; Manohar L. Garg; Megan E. Jensen; Clare E. Collins

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Lisa Wood

University of Newcastle

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Cheryl Lum

University of Newcastle

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