Metabolism and Obesity

Associate Professor David Dunstan
Head, Physical Activity
david.dunstan@bakeridi.edu.au 

Laboratory Overview

There is substantial evidence that physical activity contributes to the primary and secondary prevention of several chronic diseases and is associated with a reduced risk of premature death. Through its substantial influence on energy expenditure, regular physical activity plays an important role in preventing obesity.

The Physical Activity laboratory seeks to undertake research that will facilitate the ongoing development and refinement of evidence-based physical activity programs for people in the wider community living with, or are at risk of chronic disease. This encompasses the following research disciplines:

Epidemiology

Examines the factors affecting the health and illness of populations, and serves as the foundation and logic for the development of interventions in the interest of public health and preventive medicine. It is considered a cornerstone methodology of public health research, and is highly regarded in evidence-based medicine for identifying risk factors for disease and determining optimal treatment approaches to clinical practice.   Previously we have examined the cross-sectional associations between both physical activity and sedentary behaviour (particularly TV viewing time) and the prevalence of abnormal glucose metabolism, the metabolic syndrome, cardio-metabolic risk and mortality in Australian adults. These studies have confirmed that physical activity and sedentary behaviour are independently associated with these health outcomes.

Biomedical/ Clinical

This encompasses both short-term (acute) and long-term (intervention) studies investigating the impact of physical activity and sedentary behaviour on metabolic and physiological outcomes in adults with and without chronic disease. Research undertaken in the laboratory has provided considerable knowledge on the efficacy of resistance training (strength training) in type 2 diabetes and the metabolic benefits of regularly breaking up sitting time.

Behavioural Research

This encompasses short-term and long-term intervention studies designed to provide new knowledge on behavioural strategies to influence people at risk for chronic disease to adopt healthy, self-care behaviours in the community setting through participation in physical activity and reducing sedentary behaviour. It also seeks to establish strategies where behavioural change can be maintained in the long-term.

Translational Research

This involves the systematic evaluation of the evidence-based programs developed within the Physical Activity that have been translated to various community settings (eg Lift for Life). This includes evaluation research covering the processes and impact on health outcomes. This research underpins the continued development of community-based programs for people with or at risk of chronic disease.

A significant development for the laboratory has been the establishment of a state-of-the art Healthy Lifestyle Research Centre. The centre is located within the new Alfred Centre facility and houses new equipment and laboratories to undertake clinical and behavioural intervention studies targeting physical activity and sedentary behaviour. It's envisaged the centre will serve as the hub for the translation of evidence-based programs to the wider community.

Research Focus

• Physical activity in the prevention and treatment of chronic disease
• Sedentary behaviours and health outcomes
• Evidence-based physical activity community interventions
• Workplace sedentary time interventions

Research Projects

IDLE (Intensity Defined Little Exercise) Breaks for Reducing Diabetes Risk

Group Leader: Associate Professor David Dunstan, Dr Robyn Larsen

There is emerging evidence that people who break up their sitting time with activity breaks (such as light walking) may have a better blood glucose and blood fat levels than people who sit for prolonged periods withougt activity breaks.

This study aims to test the effects of a single bout (seven hours) of prolonged sitting on blood glucose and blood fat levels, with and without intermittent bouts of light intensity or moderate intensity activity.

The proposed trial will provide information that will assist in the design, implementation and evaluation of strategies that target reducing sedentary behaviour in those at risk of type 2 diabetes.

ABLE (Accumulative Benefits of Light Exercise) Breaks for Reducing Diabetes Risk

Group Leader: Associate Professor David Dunstan, Dr Robyn Larsen

This study will build on the findings of the IDLE breaks study which examined the acute (single day) effects of prolonged sitting with and without intermittent activity breaks.

The proposed study will involve two treatment conditions consisting of three consecutive seven hour days in a laboratory setting, separated by a one-week wash out. Overweight/obese participants will receive both of the treatment conditions (prolonged sitting with or without intermittent bouts of light intensity activity) in a randomised manner.

Click here to find out if you are eligible to participate in this study 

Understanding the efficacy of reducing workplace sedentary time through increased standing on cardio-metabolic health: an experimental study using a simulated workplace environment

Group Leader: Associate Professor David Dunstan, Dr Alicia Thorp

This study will examine the short-term (10 days) effects of reducing workplace sedentary time through routine bouts of standing on cardio-metabolic biomarkers (fasting and postprandial plasma glucose, insulin, plasma lipids and free fatty acids) and energy expenditure in overweight/obese males in a simulated office environment.

Its envisaged findings from this study will inform occupational health and public health policy in relation to the development of workplace sitting/standing time guidelines (particularly workplaces where prolonged sitting may be non-discretionary) with the aim of improving the cardio-metabolic health of Australian employees.

Measurement of Sitting Behaviour in the Workplace: The STAND UP AUSTRALIA Study

Group Leader: Associate Professor David Dunstan, Dr Alicia Thorp

This study will focus on gathering a better understanding of the research issues related to the measurement of sitting behaviour in working adults. Specifically it aims to determine the most feasible ways to measure sitting behaviour objectively and accurately, in a typical sample of working adults.

2-Year Follow-Up of a Behavioural Intervention for the Adoption and Maintenance of Physical Activity in Type 2 Diabetes (STRONG Study)

Group Leader: Associate Professor David Dunstan, Dr Carol Robinson

This study will comprise a follow-up of participants who have recently completed a 12 month NHMRC-funded randomised, controlled intervention trial; the Strength TRaining ONGoing (STRONG) study.

The aim of the STRONG study was to investigate the effectiveness of incorporating motivationally tailored adherence and maintenance strategies (i.e. phone calls, newsletters and incentives) into the existing Baker IDI-developed "Lift for Life" specialised strength training program.

STRONG study participants included:
• 318 males and females
• aged 40-75 years
• with or at risk of developing type 2 diabetes
• not undertaking regular strength training
• from metropolitan Melbourne and Geelong areas.

All participants received twice weekly group 1-hour strength training sessions with a personal trainer for 6 months and completed one of two 6 month interventions: Lift for Life program + physical activity-based behavioural intervention (Enhanced Lift For Life) versus the Standard Lift for Life program.

During the STRONG study behavioural, metabolic, physiological and functional measurements were undertaken (at baseline, 6 and 12 months).

The proposed 18 month duration follow up study seeks to evaluate the long-term maintenance of the behavioural, metabolic, physiological and functional changes through the reassessment of participants at the 12-month and 24-month time points after the completion of the initial 6 months of the STRONG study (the twice weekly group 1-hour strength training sessions with the personal trainer).

274 previous STRONG study participants have been invited to participate with 205 participants completing follow up assessments at the Healthy Lifestyle Research Centre and the remaining 66 in Geelong.

This project is funded by BUPA Health Foundation

Lab Head Profile

Associate Professor Dunstan is a VicHealth Public Health Research Fellow. His research focuses on the role of physical activity and sedentary behaviour in the prevention and management of chronic diseases. His research program has attracted considerable external funding from the NHMRC, VicHealth and the National Heart Foundation and he has been an invited speaker at international conferences, including the American Diabetes Association and the Danish Society of Public Health.
 
Associate Professor Dunstan leads a collaboration consisting of key researchers in the field of physical activity, sedentary behaviour and health to analyse the lifestyle risk factor data collected from the Australian Diabetes Obesity and Lifestyle (AusDiab) study. He is also the creator of the purposefully developed physical activity program titled ‘Lift for Life®', which has been designed to facilitate widespread uptake of strength training in community facilities such as gyms and community health centres.

Achievements/Awards

• One of the leading authorities and pioneer in sedentary behaviour research
• Has provided pioneering research into the health benefits of strength training in the treatment of individuals with type 2 diabetes and is considered to be one of the most prolific researchers on this topic
• Publications in high impact journals such as Circulation, Diabetes Care, Diabetologia, Obesity Reviews, Journal of the American Society of Nephrology, Journal of the American College of Cardiology
• Has been an invited speaker at numerous national and international conferences and institutions, including USA, Europe and New Zealand
• In 2007, he was awarded a prestigious young Tall Poppy Science award (Victoria) from the Australian Institute of Policy and Science which recognises the achievements of Australia's outstanding young scientific researchers.
  

Publication Highlights

• Dunstan DW, Daly RM, Owen N, Jolley D, de Courten M, Shaw JE, Zimmet PZ - High-intensity resistance training improves glycemic control in older patients with type 2 diabetes. Diabetes Care 25: 1729-1736 (2002)
• Dunstan DW, Salmon J, Owen N, Armstrong T, Zimmet PZ, Welborn TA, Cameron AJ, Dwyer T, Jolley D, Shaw JE: AusDiab Steering Committee. Physical activity and television viewing in relation to risk of undiagnosed abnormal glucose metabolism in adults. Diabetes Care 2004 27: 2603-2609
• Healy GN, Dunstan DW, Salmon J, Cerin E, Shaw JE, Zimmet PZ, Owen N. Breaks in sedentary time: beneficial associations with metabolic risk. Diabetes Care 2008 31: 661-666.
• Dunstan DW, Barr ELM, Healy GN, Salmon J, Shaw JE, Balkau B, Magliano DJ, Cameron AJ, Zimmet PZ and Owen N. Television Viewing Time and Mortality: The AusDiab Study. Circulation. 2010: 121: 384-391
• Owen, N., Healy, G.N., Mathews, C. E. and Dunstan, D. W. Too much sitting: the population-health science of sedentary behavior. Exercise and Sports Sciences Reviews 2010 38: 105-113
   

Key Staff

Contact

Direct +61 3 8532 1873
Email: david.dunstan@bakeridi.edu.au

Related Links

Article in the Sydney Morning Herald - Sitting Ducks