Centre for Physical Activity and Nutrition

Obesity prevention – implications for physical activity

promotionProfessor Boyd Swinburn

Centre for Physical Activity and Nutrition School of Health Sciences

Deakin UniversityMelbourne

Centre for Physical Activity and Nutrition

Increasing obesity in all countries

0

5

10

15

20

25

30

35

1980 1983 1989 1995 2000

%O

bese (

BM

I>3

0)

AustraliaNZUSANetherlandsFinland

Centre for Physical Activity and Nutrition

Increasing childhood overweight and obesity

• Overweight + obesity (1995), boys 19.5%, girls 21%

• Adult diabetes now seen in adolescents

• NO monitoring of the situation

0

5

10

15

20

25

30

7-11 12-15 7-11 12-15

1985* 1995* 2000#

Boys Girls

%

y

*Daniels et al 2001 - national data#Goodman et al 2002 – single NSW school

Centre for Physical Activity and Nutrition

Australian children versus England and USA

0

5

10

15

20

25

30

Boys Girls Boys Girls Boys Girls

Obese

Overweight

England Australia USA1994 4-11y/o 1995 7-11y/o 1991 6-11y/o

Definitions by Cole et alLihui & Bell (in press)

Centre for Physical Activity and Nutrition

What do decision-makers need to know

about obesity?• What is the size of the problem?– Increasing prevalence rates, burden of disease, cost

of illness, comparative risk assessment etc

• What are the causes?– Simple but complex– Reviews, WHO Technical Report #916

• What can be done about it?– Bits and pieces of evidence– No evidence on a comprehensive program– No success at obesity prevention in whole populations

Centre for Physical Activity and Nutrition

Burden (‘costs’) of childhood overweight

and obesityChildho

odAdultho

od

Direct costs (govt, personal) o c o cIndirect(lost productivity, early death) o c o cIntangible(loss of quality of life) o c o c

O = overweight/obesity C = complications of obesity

Centre for Physical Activity and Nutrition

Causes of obesity – convincing evidence

WHO Technical Report #916 (www.who.int)

• Regular physical activity (protective)• Sedentary lifestyle (causative)• Diet high in fibre (protective) • High intake of energy-dense foods

(causative) – ED foods are mainly high in fat and/or

sugar– High fat, vegetable-based foods may not

be very energy dense

Centre for Physical Activity and Nutrition

Target groups for prevention

• Adults– Substantial treatment component– Fewer options and issues about free choice

• High risk adults– Probably cost effective

• Children and adolescents– More potential interventions – Greater influence of environments– Greater appeal to public and politicians– Need to be aware of communication dangers

Centre for Physical Activity and Nutrition

How much PA is needed to prevent unhealthy weight gain in adults?

• We don’t know• For post-obese

– About 90 minutes per day

• For adults in sedentary occupations – Almost certainly more than 30 minutes

moderate intensity PA on most days– More like 45-60 minutes per day

Centre for Physical Activity and Nutrition

Prevention of childhood obesity

• Childhood obesity increasing everywhere• No country has a comprehensive program• Evidence on interventions ranges from

thin to non-existent to impossible-to-get• Urgent needs

– Policy leadership – Serious funding– Public advocacy– Evidence

Centre for Physical Activity and Nutrition

Lessons from obesity prevention research to

date• Education (esp curriculum) alone has little impact

• Reducing TV viewing has significant effect on decreasing BMI

• School studies cannot usually get a high enough dose of intervention

• Long duration is needed to see effects

• ?role of RCTs in prevention trials

Centre for Physical Activity and Nutrition

Best Investments to Address Childhood

Obesity• Project funded by Commonwealth

Department of Health and Ageing• 3 components

– Develop appropriate structure for a comprehensive approach

– Estimating effectiveness of interventions– Estimating health care costs and therefore

the warranted investment in prevention

Centre for Physical Activity and Nutrition

Proposed structure(structure/content developed with ~50

Australian experts)• Essential elements

– Communication and education – Whole-of-community demonstration areas– Co-ordination and capacity building– Monitoring and research

• Settings– (Homes), schools*, pre-schools*, neighbourhoods, fast

food outlets, primary care, ante/post natal care

• Sectors– Food supply, food marketing*, (transport, urban

planning)

* = high priority

Centre for Physical Activity and Nutrition

prevalence of childhood overweight & obesity

TV viewing

Fast food outlets

Active neighbour-hoods

Interventions (examples)

Estimated effectiveness

Warranted investment

Economic cost of obesity (O) & its complications (C)

Direct

Indirect

Intangible

Childhood Adulthood

COCO

COCO

COCO

Schema for the threshold analysis for reducing childhood obesity

evidence modelling

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Modelling • First pass of modelling economic

costs and intervention effectiveness completed but remains confidential– Many of the modelling methods are new

& assumptions need to be agreed upon– Needs greater consultation, other data

to fill gaps, and peer review– First pass gave politically difficult results – Able to discuss methodology

Centre for Physical Activity and Nutrition

Average number of food advertisements

0 2 4 6 8 10 12 14

Australia

USA

UK

France

Greece

Finland

Germany

Denmark

Netherlands

Belgium Club RTL

Norway TV3

Austria

Sweden TV4

Cou

ntr

y

Average number of food ads per hour

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Assumed pathways

Sedentariness

Physical activity

Prevalence overweight/

obesity

Food ED

Beverage ED Energy

intake

Energy output

Weight BMI

Centre for Physical Activity and Nutrition

• Sedentary behaviour– Used TV viewing BMI (Robinson,

Gortmaker) – estimate 3pp o/w obesity prevalence per 1hour TV viewing

– No modelling via EE• Physical activity

– Used the added energetic values for PA (eg walking = 0.4kJ/kg/min)

– Uncertainty about compensation (assumed 50%)

Modelling assumptions PA

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Best Investments

• Childhood O/W & obesity costs a lot of money and the ‘warranted investment’ in prevention is large

• A comprehensive prevention program should substantially reduce prevalence

• Currently being considered by the National Obesity Taskforce

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Whole-of-community demonstration areas

• Funding is scarce – Need to concentrate to have greatest

effect• Lack of evidence

– Need to closely evaluate interventions• Dose needs to be high

– Multiple strategies in multiple settings• Need intersectoral collaboration

– Better at local level

Centre for Physical Activity and Nutrition

Sentinel Site for Obesity Prevention

Barwon-South Western Region of Victoria

Warrnambool Colac Geelong

Centre for Physical Activity and Nutrition

Aims of the Sentinel Site

• Capacity building– To increase the knowledge and expertise in obesity

prevention and physical activity promotion

• Monitoring– To develop indicators and monitoring systems for

physical activity, nutrition and obesity

• Intervention support– To work with communities and DHS to develop and

implement multi-strategy, multi-setting interventions

• Evaluation– To evaluate the effects of the interventions and

disseminate findings

Centre for Physical Activity and Nutrition

Sentinel Site: Proposed schema for action

TimeRegular monitoring of region: Monitor PAN environments, behaviours, outcomes in a variety of settings. Use for baseline and outcome variables for interventions, assessment of program reach and population impact. Linked to state/national monitoring programs.

Develop indicators,Pilot testing,monitoring design

Demo area 1 - interventions & evaluation

Demo area 2 – interventions & evaluation

Demo area 3 – interventions & evaluation

Act

ivit

ies

Develop and support interventions

Increase capacity, training

2002 2003 2004 2005

ReachSustainability

2006

Centre for Physical Activity and Nutrition

Choosing sites

• Why Barwon-SW?– Strong, existing Deakin-DHS (BSW)

partnerships– Strong, existing nutrition & PA networks– Range of SES and rural/small town/urban

• Which demonstration area?– Good existing infrastructure, relationships,

expertise– Geographical bounds– Needs, SES, community capacity

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Progress to date

• Funding from DHA, DHS, VicHealth• Colac Y1

– Partnerships & structures, coordinator, planning, training (ANGELO, social marketing, schools, GPs), action plan, baseline measurements

• Monitoring– Outcomes (BMI), behaviours (PA, eating),

determinants (policies, environments etc)– Schools, LGA

• Course development for Obesity Prevention

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Action plan

• ANGELO process – scan environments, prioritise target behaviours, env actions, communication messages

• Comprehensive planCommunications Capacity building

Monitoring TV viewing

Sugar drinks water ED snacks fruit

Active transport Active play (3-6pm)

Fast food outlets Mgt for o/w children

Centre for Physical Activity and Nutrition

Conclusions

• The rising obesity epidemic is the largest preventable health problem in Australian children

• A comprehensive, multi-strategy, multi-setting approach is needed to reverse it

• Whole-of-community demonstration areas are needed to build the evidence