baur - tackling causes of the causes - youth health forum

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Obesity in young people: tackling the causes of the causes

Youth Health Forum – August 2016

Louise A BaurUniversity of Sydney: Discipline of Child & Adolescent Health, Sydney Medical School, AND Sydney School of Public Health

The Children’s Hospital at Westmead, Sydney: Weight Management Services

Email: [email protected]

Obesity

• A serious, chronic, relapsing disease

→ But is it really an issue for young people?

Is it a problem?Globally

http://www.iaso.org/resources/obesity-data-portal/resources/maps/

http://www.iaso.org/resources/obesity-data-portal/resources/maps/ http://www.iaso.org/resources/obesity-data-portal/resources/maps/

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http://www.iaso.org/resources/obesity-data-portal/resources/maps/

Is it a problem?In Australia?

Proportion of school‐children with overweight & obesity (Body mass index)

International Obesity Taskforce cut‐points; 1985 Health & Fitness Survey; 1995 National Nutritional Survey; 2007 National Children's Nutrition & PA Survey; 2012/2014 Australian Health Survey

0

5

10

15

20

25

30

1985 1995 2007 2012 2014

Obese

Overwt

10.0%

15.7%

17.2%18.3%

1.7%

5.2%

7.4%7.5%

7.4%

20.2%

Garnett SP et al Obesity Reviews 2011; Garnet SP et al PLOS One 2016

0

5

10

15

20

25

30

1985 1995 2007 2012

Australian school‐children are changing shape

Waist to height ratio ≥0.5Overweight/obesity (BMI)

Garnett SP et al Obesity Reviews 2011; Garnet SP et al PLOS One 2016

1985 Health and Fitness Survey; 1995 National Nutritional Survey; 2007 National Children's Nutrition & PA Survey; IOTF cut‐points to adjust for age and sex; Morbid obesity equivalent to adult BMI >35

0

5

10

15

20

25

30

1985 1995 2007 2012

Morbid

Obese

Overwt

Increased central adiposity for the same weight & height

3

High

Medium

Low

1.0 2.0

Socioeconomic position: Adjusted odds ratios for overweight & obesity in Australian secondary school students

National Secondary Students Diet and Activity Survey 2009-2010; 12,000 students Years 7-10. Morley BA et al. MJA 2012; 196:189-192.

Youth of lower SEP are 1.67 times more likely to be affected

So, what is causing this epidemic?

Numerousenvironmentalinfluences

Genetic predisposition

Chronic energy imbalance

Energy expenditure

Energy intake

Numerousenvironmentalinfluences

Genetic predisposition

Chronic energy imbalance

Energy expenditure

Energy intake

epigenetic influences; medications; parenting styles; psychosocial stress; smoking; early life factors…

Broader socioeconomic factors influence energy balance

It is the environment which

determines whether an

individual’s genetic predisposition

to obesity is manifest or not

4

z

Our cultural wallpaper

In the early 21st centurythe unhealthy choices

(around food and physical activity) are the easy choices

The default response to most westernised environments – especially

much of Australia – is to be less physically active and more sedentary

Changes in urban design have moved us into cars and stopped active transport

Walking is less likely ….

… where there’s just one land use and nowhere to walk to

5

0

5

10

15

20

25

30

35

USA

Canad

a

United

Kin

gdom

France

Italy

German

y

Sweden

Austri

a

Nether

lands

Switzer

land

Denmar

k

Per

cent

of

Obe

sity

0

10

20

30

40

50

60

Per

cent

of

Wal

k, C

ycle

and

Pub

lic T

rans

it

Obesity Walk, Cycle, Public Transit

Does car-dependency make us fat? Obesity falls sharply with increased walking, cycling, and transit use!

Source: Pucher and Dijkstra, Promoting Safe Walking and Cycling to Improve Public Health, Am Journal of Public Health, 2003.

Copyright ©2006 BMJ Publishing Group Ltd.Lean, M. et al. BMJ 2006;333:1261-1264

Safe cycle lanes, Netherlands ….

…. versus traffic snarls in Sydney

Community design can promote walking – or not! Charlottesville, Virginia

Existing conditions

Definitely not conducive to walking!

But how might this influence walkability?

Public street improvements, low-density private development

Public street improvements with roundabout, medium-density private development

Or this?

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Street trees

Or even this? We have become much more sedentary!

Prevalence of obesity and TV viewing 12-17 year olds (Dietz & Gortmaker, 1985)

0

5

10

15

20

25

0 - 1 1 - 2 2 - 3 3 - 4 4 - 5 >5

TV hours per day

Ob

esit

y p

reva

len

ce (

%)

Screen time has increased

The default response to most westernised environments – especially much of Australia – is also to passively

consume extra calories

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A bewildering array of junk food, marketed in many ways to appeal to young & old

Celebrity endorsement. Is junk food really a part of their training regimen?

How easy is to know exactly what you are eating – without several university degrees?!

McDonald D. Challenging Ronald: McDonald vsMcDonald’s. J Paediatr Ch Health 2012; 48: 103-105.

Location, location! Fast food outlets and schools

Serve sizes are bigger now than in the past

Models of obesity causationUK Foresight Report

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UK Foresight ReportObesity: a “complex system”

• UK Foresight “Tackling Obesities: Future Choices” (UK Government Office for Science, 2007)

• A series of maps showing causal loops centred around the basic energy balance “engine” of the individual

http://www.bis.gov.uk/foresight/our-work/projects/current-projects/tackling-obesities

The “System Engine”Foundational loop- basic energy balance

Positive causal loopNegative causal loop

The “System Engine” is influenced in a number of ways

Full Generic MapThematic clusters

Source: Foresight ‐ Tackling obesities: future choices ‐ http://www.foresight.gov.uk/Obesity/Obesity_final/Index.html

Full Generic Map Weighted Causal Linkages

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!!!!!Models of obesity causation

International Obesity Taskforce

COMMUNITYLOCALITY

Agriculture/Gardens/

Local markets

Health Care

PublicSafety

PublicTransport

Manufactured/Imported

Food

Sanitation

Modified from Ritenbaugh C, Kumanyika S, Morabia A, Jeffery R, Antipatis V. IOTF website 1999: http://www.iotf.org

POPULATION

%OBESE

AND

OVER-WEIGHT

WORK/SCHOOL/HOME

SchoolFood &Activity

Infections

Labour

Worksite Food & Activity

LeisureActivity/Facilities

Family &Home

INDIVIDUAL

EnergyExpenditure

Food intake :

Nutrient density

Societal policies and processes influencing the population prevalence of obesity

NATIONAL/ REGIONAL

Education

Food & Nutrition

Urbanization

Health

Social security

Transport

Media &Culture

Nationalperspective

INTERNATIONALFACTORS

Development

Globalizationof

markets

Media programs

& advertising

COMMUNITYLOCALITY


Local markets

Health Care

PublicSafety

PublicTransport


Food

Sanitation


POPULATION

%OBESE

AND

OVER-WEIGHT

WORK/SCHOOL/HOME


Infections

Labour



Family &Home

INDIVIDUAL

EnergyExpenditure

Food intake :

Nutrient density


NATIONAL/ REGIONAL

Education

Food & Nutrition

Urbanization

Health

Social security

Transport

Media &Culture

Nationalperspective


Development

Globalizationof

markets

Media programs

& advertising

Most of these factors lie well beyond the capacity of the individual,

the family or even the Health Sector to modify

Hence the need for a trans-sectoral and whole-of-government

approach to obesity prevention

Implications of these models of causation

• Change or intervention is needed across the whole of the “system map” or along the “causal pathway”

• Interventions at multiple levels are needed

• No “one thing” has gone wrong and needs to be corrected. However, some interventions may be necessary, although not sufficient, for change to occur (e.g. school interventions)

• A focus just on the young person and the family &/or school environment is unlikely to lead to long-term improvements in obesity prevalence

So how can obesity be tackled?

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Individualbehaviour change

Adapted from Puska P, 2004

Healthy eatingHealthy activityHealthy weight

Complementary approaches to prevention

The environmental gradient is steep

Environmental change





So, changing the gradient …






… will make it easier to change behaviour


So, what approaches can:

Make the gradient less steep?

and/or

Support individuals and families to change behaviour?

General comments

• Many factors have led to the development of obesity – hence, likely to respond to interventions acting at many points on the causal pathway

• Focus of research has been on a limited number of settings e.g. schools, workplaces

• Little research on:– interventions that work outside the healthcare,

school and care sector– up-stream interventions– strategies that work with older adolescents &

young adults, or high-risk groups

Many reports on what to do!

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Great recommendations in these reports

Most based on reasonable evidence, or are reasonable guesses, or have additional

health/ societal benefits

NSW Health is leading in planning and implementation for many state level

initiatives

But few strategies have been adopted at a national level

COMMUNITYLOCALITY


Local markets

Health Care

PublicSafety

PublicTransport


Food

Sanitation


POPULATION

%OBESE

AND

OVER-WEIGHT

WORK/SCHOOL/HOME


Infections

Labour



Family &Home

INDIVIDUAL

EnergyExpenditure

Food intake :

Nutrient density


NATIONAL/ REGIONAL

Education

Food & Nutrition

Urbanization

Health

Social security

Transport

Media &Culture

Nationalperspective


Development

Globalizationof

markets

Media programs

& advertising

The upstream drivers of obesity are generally

not being tackled

Upstream prevention of adolescent obesity – some examples of what are yet to be tackled

• Food marketing to children & young people– TV and radio, point of sale, school environs, web-sites,

social media …

• Food labelling– Provision of youth- and consumer-friendly information about

fat, sugar, salt & energy content

• Urban planning & transport policies– to promote active neighbourhoods, increased incidental

activity and active transport

• Agricultural, food transport & pricing policies– to improve availability, and decrease the cost, of healthy

food choices – in schools, workplaces, local markets and supermarkets

• The drivers of inequity, poverty, unemployment!! ….

We need new ways of thinking and doing policy if real changes are to occur

Would you have seen a link between combating climate change and dealing with obesity?

Moir, Sydney Morning Herald, 2007

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Final reflections

• No simple solution. No quick fix

• Some hopeful signs for primary school children!!

• BUT adolescents????

– School-based interventions necessary, BUT only a (smallish) part of the solution

Community ownership, and political will be needed, to tackle the broader upstream issues

Acknowledgements

• Members of The Children’s Hospital at Westmead (CHW) Weight Management Services team, and the CHW Obesity Research Group

• Members of the Healthy Beginnings Trial and the EPOCH study groups

• Staff of CHW Endocrinology and Sleep Units

• The Early Prevention of Obesity in Childhood (EPOCH) CRE!

• PIs, CIs, research students & members of the following research teams: HIKCUPS, LEAP, Metformin trial, PEACH, RESIST, Loozit …

• Members of the Prevention Research Collaboration and the Boden Institute at the University of Sydney

• Members of the former Australasian Child & Adolescent Obesity Research Network

Thank you!

baur - tackling causes of the causes - youth health forum

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