Risk factors: Thats life

1
Risk factorsThats life!

• Mark Cooper-StanburyAIHW

2
Overview

• The risk factors web
• A focus on three diet, physical activity and
  body weight
• What Australias Health 2006 reports
• Taking a broader view
• Data priorities for Australia

3
Introduction the complexity of risk factors
4
Conceptual framework
Generalbackgroundfactors Environ-mentalfacto
rs
Socio-economiccharacteristics Knowledgeandat
titudes
Healthbehaviours Psychologicaleffects Safety
factors
Biomedicalfactors
Individual and population health
Individual makeup
See Figure 3.1 in Australias Health 2006 for
more detail.
5
A focus on three
6
The energy equation

• Intense public media focus on overweight and
  obesity
• Everyone has a personal stake
• Newsworthy
• Health behaviours
• Dietary behaviour (energy in)
• Physical activity (energy out)
• Biomedical factors
• Body weight( energy in energy out).

7
What we report
8
Dietary behaviours

• A major risk/protective factor for
• Heart disease, stroke and high blood pressure
• Many cancers
• Diabetes
• Osteoporosis
• Overweight and obesity.
• Around 1.4 of the burden of disease (BoD) and
  injury is attributed to inadequate fruit and
  vegetable intake.

9
Dietary behaviours (cont.)

• Should be seen in the context of Dietary
  Guidelines
• Eat a wide variety of nutritious foods
• Take care to limit intake of fat, alcohol, salt
  and sugar
• Be physically active
• Prepare and store food safely
• Encourage and support breastfeeding.

10
Dietary behaviours (cont.)

• Prevalence of inadequate fruit and vegetable
  consumption

Persons aged 18 years and over. Source
Australias Health 2006Table 3.15.
11
Dietary behaviours (cont.)

• Saturated fat intake
• Australian adults sourced 13 of their energy
  from saturated fat (c.f. recommended 10)
• 52 males and 39 females consumed full-cream
  milk (an indicator of saturated fat intake).

12
Physical activity

• Protective factor for
• Heart disease and high blood pressure
• Some cancers
• Diabetes
• Osteoporosis
• Mental wellbeing
• Overweight and obesity.
• Around 6.8 of total BoD attributed to physical
  inactivity.

13
Physical activity (cont.)

• Should be seen in context of Physical Activity
  Guidelines
• 30 minutes of moderate-intensity PA on most
  days, or a total of 150 minutes per week
• for children, 60 minutes every day.

14
Physical activity (cont.)

• Prevalence of insufficient activity
• Males 45.6
• Females 52.4
• Persons 49.1
• Sedentary behaviour
• 3035 of adult Australians have less than 100
  minutes of exercise over a two-week period.

Persons aged 18 years and over. Less than 150
minutes and/or fewer than five session. Source
Australias Health 2006Figure 3.4.
15
Body weight (mass)

• Increasing prevalence of overweight/obesity
  (OO) termed a global epidemic by WHO.
• Risk factor for
• Diabetes
• Heart disease and high blood pressure
• Some cancers
• Osteoarthritis
• Sleep disorders
• Psychological disorders and social problems.
• Accounts for 5.0 of Australian BoD.

16
Body weight (cont.)

• The body mass index (BMI) concept
• Weight/Height2
• e.g. my BMI 65kg/1.82219.6
• WHO classification of BMI
• Underweight lt 18.5
• Normal 18.5 lt 25
• Overweight 25 lt 30
• Obese 30
• My normal weight range is 6183kg.

17
Body weight (cont.)

• Prevalence of overweight and obesity

Persons aged 18 years and over. Source Table
3.17.
18
Body weight (cont.)

• Obesity by age and sex

Source AusDiab 1999-2000.
19
Taking a broader view
20
The overweight controversy

• Large amount of evidence that being overweight is
  healthier than normal weight
• Flegal et al. 2005 showed that both underweight
  and obese were associated with excess mortality
  (compared with normal weight), but overweight was
  not
• Many other studies with similar findings.

21
Another problem

• The BMI categories are a bit simplistic the
  relationship between body mass and health is
  likely more complex
• Continuous rather than discrete function
• As the framework at the beginning showed, health
  is an outcome of a range of risk and protective
  factors
• We are tempted to use obesity as aproxy for
  other ill health.

22
Nutrition is more than energy in

• Diet is not just about calories, although thats
  important
• One excess slice of bread per day adds 4kg per
  year to your body mass
• Conversely, it takes an overall deficit of more
  than 32,000kJ to lose 1kg of body fat
• Given that one Big Mac yields 2,010kJ (480 Cal)

23
Just forego this
24
A broader view of diet

• Diet is also not just about fruit and vegetables
• Although it is likely that if you are meeting the
  recommendations here your overall diet quality is
  good.
• The Guidelines are quite clear that total diet
  quality is important
• Variety of foods
• Sources of energy
• Appropriate micronutrients (e.g. folate).

25
PA is more than energy out

• Although thats important
• ½ hour of walking at moderate pace burns around
  900 kJ
• 2 hours of ironing burns over 2,000 kJ!
• Not everyone is able to do the recommended number
  of minutes or number of sessions.

26
A broader view of PA

• Other patterns/intensity can still be
  health-conferring
• Sufficient PA typically often narrowly
  interpreted with respect to cardiovascular
  health
• Range of movement exercises, for example, would
  be important following joint replacement surgery.

27
Data priorities
28
The problem with self-report

• Most of the measures reported here are
  self-report and subjective.
• We know that people typically
• Under-assess their energy consumption by up to
  25
• Over-assess their activity levels
• Over-report their height and under-report their
  weight (and the error increases as people age).

29
Objective is better

• We need objective measures of
• Diet quality/sufficiency
• Physical activity/inactivity
• Body mass, body fat and body fat distribution.
• We need these repeated over time.

30
Other needs

• Similar measures for children.
• Measures of other health-conferring types of
  physical activity.
• Conceptual development of total risk relative
  to specific outcomes.

31
Questions and comments?